Hume’s Hume’s TreatiseTreatise, Book 1, Book 1

Peter MillicanPeter Millican

Hertford College, OxfordHertford College, Oxford

4. Of Knowledge and 4. Of Knowledge and ProbabilityProbability

4(a)4(a)

Relations, and a Relations, and a detour via the detour via the Causal MaximCausal Maxim

33

““Of Knowledge and Probability”Of Knowledge and Probability”

Despite the title of Despite the title of TreatiseTreatise 1.3: 1.3:– Only Only T T 1.3.1 deals with “Knowledge” (a 1.3.1 deals with “Knowledge” (a

word Hume uses in a strict sense, as word Hume uses in a strict sense, as meaning meaning deductivedeductive knowledge). knowledge).

– Apart from the Apart from the titletitle of of T T 1.3.2, “probability” 1.3.2, “probability” doesn’t make an entrance until doesn’t make an entrance until T T 1.3.6.4.1.3.6.4.

The real unifying theme is the idea of The real unifying theme is the idea of causationcausation, and causal reasoning. But , and causal reasoning. But Hume’s route to his account of it is Hume’s route to his account of it is rather circuitous …rather circuitous …

44

Hume’s Dichotomy AgainHume’s Dichotomy Again

Hume divides his seven types of relation Hume divides his seven types of relation into two groups into two groups (T(T 1.3.1.1) 1.3.1.1)::– The Four “Constant” RelationsThe Four “Constant” Relations

Those relations that ‘depend entirely on the Those relations that ‘depend entirely on the ideas, which we compare together’ (i.e. ideas, which we compare together’ (i.e. resemblanceresemblance, , contrarietycontrariety, , degrees in qualitydegrees in quality, , proportions in quantity or numberproportions in quantity or number););

– The Three “Inconstant” RelationsThe Three “Inconstant” RelationsThose relations that ‘may be chang’d without Those relations that ‘may be chang’d without any change in the ideas’ (i.e. any change in the ideas’ (i.e. identityidentity, , relations relations of time and placeof time and place, , cause and effectcause and effect).).

55

A Taxonomy of Mental OperationsA Taxonomy of Mental Operations

Hume argues, rather simplistically, that his Hume argues, rather simplistically, that his seven relations map neatly onto four seven relations map neatly onto four different mental operations:different mental operations:– resemblanceresemblance, , contrarietycontrariety, and , and degrees in qualitydegrees in quality

are “discoverable at first sight” (are “discoverable at first sight” (TT 1.3.1.2) 1.3.1.2)– proportions of quantity or numberproportions of quantity or number are susceptible are susceptible

of demonstration (of demonstration (TT 1.3.1.2-5) 1.3.1.2-5)– identityidentity and and relations of time and placerelations of time and place are matters are matters

of perception rather than reasoning (of perception rather than reasoning (TT 1.3.2.1) 1.3.2.1)– causationcausation is the only relation “that can be trac’d is the only relation “that can be trac’d

beyond our senses, [to] existences and objects, beyond our senses, [to] existences and objects, which we do not see or feel” (which we do not see or feel” (TT 1.3.2.3) 1.3.2.3)

66

Constant relationsConstant relations Inconstant relationsInconstant relations

PerceptionPerception IntuitionIntuition

resemblanceresemblance

contrarietycontrariety

degrees in qualitydegrees in quality

Sensory PerceptionSensory Perception

identityidentity

situations in time situations in time and placeand place

ReasoningReasoning DemonstrationDemonstration

proportions in proportions in quantity and numberquantity and number

ProbabilityProbability

causationcausation

77

The Idea of CausationThe Idea of Causation

To understand reasoning to the unobserved To understand reasoning to the unobserved (i.e. (i.e. probableprobable reasoning, though Hume has reasoning, though Hume has not yet used the term), “we must consider the not yet used the term), “we must consider the idea of idea of causationcausation, and see from what origin it , and see from what origin it is deriv’d” (is deriv’d” (TT 1.3.2.4). 1.3.2.4).

The search for the origin of this idea will The search for the origin of this idea will shape the remainder of shape the remainder of TreatiseTreatise 1.3. 1.3.

There is no specific quality that characterises There is no specific quality that characterises causes and effects, so it must be some causes and effects, so it must be some relationrelation between the two. ( between the two. (TT 1.3.2.5-6) 1.3.2.5-6)

88

Contiguity and PriorityContiguity and Priority

We find causes and effects to be We find causes and effects to be contiguouscontiguous in space and time (in space and time (TT 1.3.2.6), though a 1.3.2.6), though a footnote hints at a significant reservation footnote hints at a significant reservation (explored in (explored in TT 1.4.5 which points out that 1.4.5 which points out that many perceptions have no spatial location).many perceptions have no spatial location).

We also find causes to be We also find causes to be priorprior to their to their effects (effects (TT 1.3.2.7), though again Hume 1.3.2.7), though again Hume seems to indicate that this isn’t a particularly seems to indicate that this isn’t a particularly crucial matter (crucial matter (TT 1.3.2.8). 1.3.2.8).

There still seems to be something missing … There still seems to be something missing …

99

Necessary ConnexionNecessary Connexion

There follows a famous passage, which is There follows a famous passage, which is commonly misunderstood:commonly misunderstood:

““Shall we then rest contented with these two Shall we then rest contented with these two relations of contiguity and succession, as relations of contiguity and succession, as affording a compleat idea of causation? By no affording a compleat idea of causation? By no means. An object may be contiguous and prior to means. An object may be contiguous and prior to another, without being consider’d as its cause. another, without being consider’d as its cause. There is a There is a NECESSARY CONNEXIONNECESSARY CONNEXION to be taken to be taken into consideration; and that relation is of much into consideration; and that relation is of much greater importance, than any of the other two greater importance, than any of the other two above-mention’d.” (above-mention’d.” (TT 1.3.2.11) 1.3.2.11)

1010

To Neighbouring FieldsTo Neighbouring Fields

Hume is looking for the crucial extra Hume is looking for the crucial extra component (beyond component (beyond single-casesingle-case contiguity contiguity and succession) that makes up our idea of and succession) that makes up our idea of cause and effectcause and effect

It seems elusive, so he proceeds like those It seems elusive, so he proceeds like those who “beat about all the neighbouring fields, who “beat about all the neighbouring fields, without any certain view or design, in hopes without any certain view or design, in hopes their good fortune will at last guide them to their good fortune will at last guide them to what they search for” (what they search for” (TT 1.3.2.13). 1.3.2.13).

There are two such fields …There are two such fields …

1111

The Causal MaximThe Causal Maxim

The first field is the Causal Maxim:The first field is the Causal Maxim:

“’“’Tis a general maxim in philosophy, that Tis a general maxim in philosophy, that whatever begins to exist, must have a cause of whatever begins to exist, must have a cause of existenceexistence” (” (TT 1.3.3.1) 1.3.3.1)

Hume argues that this is neither intuitively nor Hume argues that this is neither intuitively nor demonstratively certain (demonstratively certain (TT 1.3.3.1-8) 1.3.3.1-8)

““Since it is not from knowledge or any scientific Since it is not from knowledge or any scientific reasoning, that we derive [this] opinion …, [it] reasoning, that we derive [this] opinion …, [it] must necessarily arise from observation and must necessarily arise from observation and experience. …experience. … ( (TT 1.3.3.9) 1.3.3.9)

1212

The Sinking of the Causal MaximThe Sinking of the Causal Maxim

… … The next question, then, shou’d naturally be, The next question, then, shou’d naturally be, how experience gives rise to such a principle?how experience gives rise to such a principle? But as I find it will be more convenient to sink But as I find it will be more convenient to sink this questionthis question in the following, in the following, Why we conclude, Why we conclude, that such particular causes must necessarily that such particular causes must necessarily have such particular effects, and why we form have such particular effects, and why we form an inference from one to another?an inference from one to another? we shall we shall make that the subject of our future enquiry. make that the subject of our future enquiry. ’Twill, perhaps, be found in the end, that the ’Twill, perhaps, be found in the end, that the same answer will serve for both questions.” same answer will serve for both questions.” ((TT 1.3.3.9) 1.3.3.9)

1313

Does Hume Accept the Causal Maxim?Does Hume Accept the Causal Maxim?

Unfortunately Hume never returns Unfortunately Hume never returns explicitly to the Causal Maxim, and some explicitly to the Causal Maxim, and some of his contemporaries took him to be of his contemporaries took him to be denying it.denying it.

But there is significant evidence that he But there is significant evidence that he accepts it, deriving both from his general accepts it, deriving both from his general deterministic outlook (as we’ll see later), deterministic outlook (as we’ll see later), and from letters that he wrote to those and from letters that he wrote to those contemporaries who misunderstood …contemporaries who misunderstood …

1414

Letter from a GentlemanLetter from a Gentleman (1745) (1745)

““it being the Author’s Purpose, in the it being the Author’s Purpose, in the Pages cited in the Specimen, to examine Pages cited in the Specimen, to examine the Grounds of that Proposition; he used the Grounds of that Proposition; he used the Freedom of disputing the common the Freedom of disputing the common Opinion, that it was founded on Opinion, that it was founded on demonstrative or intuitive Certainty; demonstrative or intuitive Certainty; but but asserts, that it is supported by moral asserts, that it is supported by moral EvidenceEvidence, and is followed by a Conviction , and is followed by a Conviction of the same Kind with these Truths, That of the same Kind with these Truths, That all Men must die, and that the Sun will rise all Men must die, and that the Sun will rise To-morrow.” (To-morrow.” (LFGLFG 26) 26)

1515

Letter to John StewartLetter to John Stewart (1754) (1754)

“… “… But allow me to tell you, that I never asserted But allow me to tell you, that I never asserted so absurd a Proposition as that any thing might so absurd a Proposition as that any thing might arise without a Cause: arise without a Cause: I only maintain’d, that our I only maintain’d, that our Certainty of the Falshood of that Proposition Certainty of the Falshood of that Proposition proceeded neither from Intuition nor proceeded neither from Intuition nor Demonstration; but from another SourceDemonstration; but from another Source. That . That Caesar existed, that there is such an Island as Caesar existed, that there is such an Island as Sicily; for these Propositions, I affirm, we have Sicily; for these Propositions, I affirm, we have no demonstrative nor intuitive Proof. Woud you no demonstrative nor intuitive Proof. Woud you infer that I deny their Truth, or even their infer that I deny their Truth, or even their Certainty?” (Certainty?” (HLHL i 186) i 186)

1616

Leading Up to InductionLeading Up to Induction

TreatiseTreatise 1.3.4 argues that causal reasoning, 1.3.4 argues that causal reasoning, if it is to result in real belief, must start from if it is to result in real belief, must start from something perceived or remembered.something perceived or remembered.

TT 1.3.5.1 sets out a corresponding agenda: 1.3.5.1 sets out a corresponding agenda:““Here therefore we have three things to explain, Here therefore we have three things to explain, viz. viz. FirstFirst, The original impression. , The original impression. SecondlySecondly, , The transition to the idea of the connected The transition to the idea of the connected cause or effect. cause or effect. ThirdlyThirdly, The nature and , The nature and qualities of that idea.”qualities of that idea.”

1717

““Of the impressionsOf the impressionsof the senses and memory”of the senses and memory”

The title of The title of TreatiseTreatise 1.3.5 seems odd, since 1.3.5 seems odd, since memory presents memory presents ideasideas, not , not impressionsimpressions..

But Hume’s main point here is that the But Hume’s main point here is that the perceptions of the senses and memory are alike perceptions of the senses and memory are alike in being more in being more strong and livelystrong and lively – having more – having more force and vivacityforce and vivacity – than the ideas of the – than the ideas of the imagination.imagination.

That force and vivacity, apparently, is what That force and vivacity, apparently, is what enables them to act as a “foundation of that enables them to act as a “foundation of that reasoning, which we build … when we trace the reasoning, which we build … when we trace the relation of cause and effect” (relation of cause and effect” (TT 1.3.5.7) 1.3.5.7)

4(b)4(b)

The Argument The Argument Concerning Concerning InductionInduction

1919

Three Versions of the ArgumentThree Versions of the Argument

TreatiseTreatise 1.3.6 contains the famous argument 1.3.6 contains the famous argument concerning induction, though Hume doesn’t concerning induction, though Hume doesn’t seem entirely to appreciate its significance – seem entirely to appreciate its significance – it is mainly a staging post in his search for the it is mainly a staging post in his search for the origin and nature of our idea of causation.origin and nature of our idea of causation.

In the In the AbstractAbstract of 1740 it is elevated to a of 1740 it is elevated to a much more prominent position, as the centre-much more prominent position, as the centre-piece of Hume’s “Chief Argument”.piece of Hume’s “Chief Argument”.

The fullest and clearest version is in the first The fullest and clearest version is in the first EnquiryEnquiry, Section 4., Section 4.

2020

A Very Brief OverviewA Very Brief Overview

Suppose we see Suppose we see AA followed by followed by BB again again and again. When we next see an and again. When we next see an AA, we , we naturally infer a naturally infer a BB. But why?. But why?– A Priori A Priori insight? insight? NoNo: : a prioria priori, we can know , we can know

nothing whatever about what causal effects nothing whatever about what causal effects AA will have. “Intelligibility” is just an illusion.will have. “Intelligibility” is just an illusion.

Such causal/probable/moral inference is Such causal/probable/moral inference is based on based on extrapolatingextrapolating into the future the into the future the associations that we have observed.associations that we have observed.

2121

Inferring UniformityInferring Uniformity

What ground can we give for extrapolating What ground can we give for extrapolating from observed to unobserved?from observed to unobserved?– Sensory knowledge? Sensory knowledge? NoNo: what we perceive of : what we perceive of

objects gives us no insight into the basis of objects gives us no insight into the basis of their powers, hence no reason to extrapolate.their powers, hence no reason to extrapolate.

– Logical intuition? Logical intuition? NoNo..– Demonstrative reasoning? Demonstrative reasoning? NoNo: neither of : neither of

these, because it’s clear that extrapolation these, because it’s clear that extrapolation couldcould fail, so it can’t be a matter of pure logic. fail, so it can’t be a matter of pure logic.

– Probable reasoning? Probable reasoning? NoNo: would be circular.: would be circular.

2222

TreatiseTreatise and and EnquiryEnquiry

In the In the TreatiseTreatise, Hume doesn’t explicitly , Hume doesn’t explicitly rule out sensation and intuition as possible rule out sensation and intuition as possible foundations for this “Uniformity Principle”.foundations for this “Uniformity Principle”.

There, he seems just to assume that There, he seems just to assume that demonstrative and probable reasoning demonstrative and probable reasoning provide the only available options.provide the only available options.

So the So the EnquiryEnquiry argument is apparently argument is apparently more more completecomplete in this respect (but in this respect (but otherwise very similar in spirit).otherwise very similar in spirit).

2323

A Simplified VersionA Simplified Version

The essential logic of the argument can be The essential logic of the argument can be represented using the ‘founded on’ relation represented using the ‘founded on’ relation (FO), together with:(FO), together with:

p Probable inference (to the unobserved)p Probable inference (to the unobserved)

c Causal reasoningc Causal reasoning

e (Reasoning from) Experiencee (Reasoning from) Experience

u Uniformity Principleu Uniformity Principle

R ReasonR Reason

d Demonstrationd Demonstration

i Intuitioni Intuition

s Sensations Sensation

2424

FO(c,e)

FO(p,u)

¬FO(p,R)

FO(e,u)

¬FO(u,s)

¬FO(u,d)

¬FO(u,R)¬FO(u,i)

¬FO(u,p)

FO(p,c)

FO(p,e)

Hume’s Argument Hume’s Argument concerning concerning

InductionInduction

Only in Only in EnquiryEnquiry

2525

The Four “Kinds of Evidence”The Four “Kinds of Evidence”

So the So the EnquiryEnquiry argument implicitly reasons: argument implicitly reasons:

¬FO(u,s) & ¬FO(u,i) & ¬FO(u,d) & ¬FO(u,p) ¬FO(u,s) & ¬FO(u,i) & ¬FO(u,d) & ¬FO(u,p) ¬FO(u,R) ¬FO(u,R)

If UP isn’t founded on sensation, intuition, demonstration If UP isn’t founded on sensation, intuition, demonstration or probable inference, then it isn’t founded on Reason.or probable inference, then it isn’t founded on Reason.

Compare this passage from Hume’s Compare this passage from Hume’s Letter Letter from a Gentlemanfrom a Gentleman (1745): (1745):

““It is common for Philosophers to distinguish the It is common for Philosophers to distinguish the Kinds of Evidence into Kinds of Evidence into intuitiveintuitive, , demonstrativedemonstrative, , sensiblesensible, and , and moral”moral”

2626

A A ScepticalSceptical Argument? Argument?

Hume’s famous argument concerning Hume’s famous argument concerning induction …induction …– Starts by showing that all probable inference Starts by showing that all probable inference

is founded on the Uniformity Principle;is founded on the Uniformity Principle;– Then goes on to undermine every available Then goes on to undermine every available

“kind of evidence” for UP;“kind of evidence” for UP;– Then draws from this the conclusion that Then draws from this the conclusion that

probable inference is not founded on reason.probable inference is not founded on reason.

This way of arguing seems to imply that This way of arguing seems to imply that the conclusion has sceptical intent …the conclusion has sceptical intent …

2727

TreatiseTreatise 1.3.6 – A Closer Look 1.3.6 – A Closer Look

Recall Hume’s aim here:Recall Hume’s aim here:– He is seeking to understand our idea of He is seeking to understand our idea of

necessary connexion (cf. necessary connexion (cf. TT 1.3.2.11). 1.3.2.11).– This leads him to ask “Why we conclude, that This leads him to ask “Why we conclude, that

… particular causes must necessarily have … … particular causes must necessarily have … particular effects, and why we form an particular effects, and why we form an inference from one to another?” (inference from one to another?” (TT 1.3.3.9). 1.3.3.9).

– The key part of this process is “the inference The key part of this process is “the inference from the impression to the idea” (cf. from the impression to the idea” (cf. TT 1.3.5.1); 1.3.5.1); call this “causal inference” for short.call this “causal inference” for short.

2828

Causal Inference Is Not A PrioriCausal Inference Is Not A Priori

Hume first argues that causal inference Hume first argues that causal inference can’t be a priori (can’t be a priori (TT 1.3.6.1), because we 1.3.6.1), because we can conceive things coming out differently.can conceive things coming out differently.

Here he makes the [common] assumption Here he makes the [common] assumption that any a priori inference would have to that any a priori inference would have to yield complete certainty.yield complete certainty.

“’“’Tis therefore by EXPERIENCE only, that Tis therefore by EXPERIENCE only, that we can infer the existence of one object we can infer the existence of one object from that of another” (from that of another” (TT 1.3.6.2). 1.3.6.2).

2929

Experience and Constant ConjunctionExperience and Constant Conjunction

The kind of experience on which causal The kind of experience on which causal inference is based is repeated patterns of inference is based is repeated patterns of one thing, one thing, AA, followed by another, , followed by another, BB::

““Without any farther ceremony, we call the one Without any farther ceremony, we call the one causecause and the other and the other effecteffect, and infer the existence , and infer the existence of the one from that of the other.” (of the one from that of the other.” (TT 1.3.6.2) 1.3.6.2)

““Thus … we have … discover’d a new Thus … we have … discover’d a new relation betwixt cause and effect, when we relation betwixt cause and effect, when we least expected it … This relation is their least expected it … This relation is their CONSTANT CONJUNCTIONCONSTANT CONJUNCTION.” (.” (TT 1.3.6.3) 1.3.6.3)

3030

““Perhaps ’twill appear in the end …”Perhaps ’twill appear in the end …”

The capitalisation in The capitalisation in TT 1.3.6.3 clearly links back 1.3.6.3 clearly links back to to TT 1.3.2.11, as does the text: 1.3.2.11, as does the text:

““Contiguity and succession are not sufficient to make Contiguity and succession are not sufficient to make us pronounce any two objects to be cause and effect, us pronounce any two objects to be cause and effect, unless … these two relations are preserv’d in several unless … these two relations are preserv’d in several instances [i.e. there’s a constant conjunction].”instances [i.e. there’s a constant conjunction].”

But how can this give rise to the new idea of But how can this give rise to the new idea of necessary connexion? Anticipating necessary connexion? Anticipating TT 1.3.14.20, 1.3.14.20,

““Perhaps ’twill appear in the end, that the necessary Perhaps ’twill appear in the end, that the necessary connexion depends on the inference, instead of the connexion depends on the inference, instead of the inference’s depending on the necessary connexion”.inference’s depending on the necessary connexion”.

3131

A Question of FacultiesA Question of Faculties

Since causal reasoning from [impression of] Since causal reasoning from [impression of] cause cause AA to [idea of] effect to [idea of] effect BB is founded on is founded on “past “past experienceexperience, and … remembrance of … , and … remembrance of … constant conjunctionconstant conjunction” (” (TT 1.3.6.4), 1.3.6.4),

““the next question is, whether experience the next question is, whether experience produces the idea [of the effect produces the idea [of the effect BB] by means of ] by means of the the understandinunderstanding or g or imaginationimagination; whether we are ; whether we are determin’d by determin’d by reasonreason to make the transition, or by to make the transition, or by a certain association and relation of a certain association and relation of perceptions?”perceptions?”

Hume will now argue that it can’t be reason.Hume will now argue that it can’t be reason.

3232

UP: The Uniformity PrincipleUP: The Uniformity Principle

In the In the TreatiseTreatise– ““If reason determin’d us [to infer effect If reason determin’d us [to infer effect BB from from

cause cause AA], it wou’d proceed upon that principle, ], it wou’d proceed upon that principle, that that instances of which we have had no experience, instances of which we have had no experience, must resemble those of which we have had must resemble those of which we have had experience, and that the course of nature continues experience, and that the course of nature continues always uniformly the samealways uniformly the same.” (.” (TT 1.3.6.4) 1.3.6.4)

– This seems This seems conditionalconditional: : IFIF reason is involved, reason is involved, THENTHEN it must be based on this principle. it must be based on this principle.

– The principle seems implausibly strong: surely we The principle seems implausibly strong: surely we don’t have to believe in don’t have to believe in completecomplete uniformity! uniformity!

3333

UP in the UP in the EnquiryEnquiry

In the In the EnquiryEnquiry– ““all our experimental [experiential] conclusions all our experimental [experiential] conclusions

proceed upon the supposition, that the future proceed upon the supposition, that the future will be conformable to the past”. (will be conformable to the past”. (EE 4.19) 4.19)

– No suggestion of conditionality (cf. also No suggestion of conditionality (cf. also EE 5.2: 5.2: “in “in allall reasonings from experience, reasonings from experience, there is a there is a step taken by the mindstep taken by the mind” corresponding to UP).” corresponding to UP).

– Much vaguer than UP in Much vaguer than UP in TreatiseTreatise, and so more , and so more plausible: we expect the future to “resemble” plausible: we expect the future to “resemble” ((EE 4.21) the past, but not copy exactly. 4.21) the past, but not copy exactly.

3434

The Role of the Uniformity PrincipleThe Role of the Uniformity Principle

Hume is not suggesting, even in the Hume is not suggesting, even in the EnquiryEnquiry, , that we think of UP that we think of UP explicitlyexplicitly when making when making inductive inferences (cf. inductive inferences (cf. TT 1.3.8.13). 1.3.8.13).

Rather, in making an inductive inference, we Rather, in making an inductive inference, we manifestmanifest the assumption of UP, in basing our the assumption of UP, in basing our inferential behaviour on past experience.inferential behaviour on past experience.– So inferring from past to future is So inferring from past to future is ipso factoipso facto treating treating

“the past [as a] rule for the future” (cf. “the past [as a] rule for the future” (cf. EE 4.21) 4.21)– Hence the question arises: can this assumption be Hence the question arises: can this assumption be

founded on reason, or is there some other founded on reason, or is there some other explanation for why we make it?explanation for why we make it?

3535

Demonstrative and ProbableDemonstrative and Probable

Hume takes for granted a Lockean framework, Hume takes for granted a Lockean framework, recognising two types of reasoning:recognising two types of reasoning:– In In demonstrativedemonstrative reasoning (which potentially reasoning (which potentially

yields “knowledge” in the strict sense), each link yields “knowledge” in the strict sense), each link in the inferential chain is “intuitively” certain.in the inferential chain is “intuitively” certain.

– In In probableprobable reasoning, some links are merely reasoning, some links are merely probable. [Note that in the probable. [Note that in the EnquiryEnquiry, Hume also , Hume also calls this “moral reasoning” or “reasoning calls this “moral reasoning” or “reasoning concerning matter of fact and existence”]concerning matter of fact and existence”]

Our modern terms are Our modern terms are deductiondeduction and and induction.induction.

3636

UP Not Founded on ReasonUP Not Founded on Reason

““let us consider all the arguments, upon which let us consider all the arguments, upon which [UP] may be suppos’d to be founded; … these [UP] may be suppos’d to be founded; … these must be deriv’d either from must be deriv’d either from knowledgeknowledge [i.e. [i.e. demonstration] or demonstration] or probabilityprobability”. (”. (TT 1.3.6.4) 1.3.6.4)

We can conceive a change in the course of We can conceive a change in the course of nature, so UP cannot be demonstratively proved. nature, so UP cannot be demonstratively proved. ((TT 1.3.6.5) 1.3.6.5)

Probable reasoning must be causal, and hence Probable reasoning must be causal, and hence founded on UP. So it cannot provide a foundation founded on UP. So it cannot provide a foundation for UP, on pain of circularity. (for UP, on pain of circularity. (TT 1.3.6.6-7) 1.3.6.6-7)

3737

The Gap in Hume’s ArgumentThe Gap in Hume’s Argument

The Uniformity Principle is not founded on:The Uniformity Principle is not founded on:– demonstrative argument from past experiencedemonstrative argument from past experience

because a change in the course of nature is because a change in the course of nature is possible, whereas any demonstrative argument possible, whereas any demonstrative argument would have to yield total certainty;would have to yield total certainty;

– probable argument from past experienceprobable argument from past experiencebecause any probable argument is itself founded on because any probable argument is itself founded on experience and hence on the Uniformity Principle.experience and hence on the Uniformity Principle.

But what if we could find a way of arguing But what if we could find a way of arguing probabilisticallyprobabilistically but but a prioria priori??– Hume just assumes this to be impossible.Hume just assumes this to be impossible.

3838

The Sceptical [?] ConclusionThe Sceptical [?] Conclusion

““Thus not only reason fails us in the discovery of the Thus not only reason fails us in the discovery of the ultimate connexionultimate connexion of causes and effects, but even of causes and effects, but even after experience has inform’d us of their after experience has inform’d us of their constant constant conjunctionconjunction, ’tis impossible for us to satisfy ourselves , ’tis impossible for us to satisfy ourselves by our reason, why we shou’d extend that by our reason, why we shou’d extend that experience beyond those particular instances, which experience beyond those particular instances, which have fallen under our observation. We suppose, but have fallen under our observation. We suppose, but are never able to prove, that there must be a are never able to prove, that there must be a resemblance betwixt those objects, of which we resemblance betwixt those objects, of which we have had experience, and those which lie beyond have had experience, and those which lie beyond the reach of our discovery.” (the reach of our discovery.” (TT 1.3.6.11) 1.3.6.11)

3939

Hume’s Alternative ExplanationHume’s Alternative Explanation

Reason can’t explain inductive inference; Reason can’t explain inductive inference; so instead, it must arise from associative so instead, it must arise from associative principles of the imagination:principles of the imagination:

““When the mind, therefore, passes from the When the mind, therefore, passes from the idea or impression of one object [the cause idea or impression of one object [the cause AA] ] to the idea or belief of another [the effect to the idea or belief of another [the effect BB], it ], it is not determin’d by reason, but by certain is not determin’d by reason, but by certain principles, which associate together the ideas principles, which associate together the ideas of these objects, and unite them in the of these objects, and unite them in the imagination.” (imagination.” (TT 1.3.6.12) 1.3.6.12)

4040

Custom and General IdeasCustom and General Ideas

Hume later calls this associative principle Hume later calls this associative principle “custom” (“custom” (TT 1.3.7.6, 1.3.8.10, 1.3.8.12-14). 1.3.7.6, 1.3.8.10, 1.3.8.12-14).

His attitude to it is not entirely negative:His attitude to it is not entirely negative:““Custom, then, is the great guide of human life. Custom, then, is the great guide of human life. It is that principle alone, which renders our It is that principle alone, which renders our experience useful to us …” (experience useful to us …” (EE 5.6, cf. 5.6, cf. AA 16) 16)

At At TT 1.3.6.14, Hume says this is essentially 1.3.6.14, Hume says this is essentially the same sort of custom as that which the same sort of custom as that which explained general ideas at explained general ideas at TT 1.1.7.7 ff. 1.1.7.7 ff.

4(c)4(c)

Belief and Belief and ProbabilityProbability

4242

““Of the nature of the idea or belief”Of the nature of the idea or belief”

Recall the agenda set at Recall the agenda set at TT 1.3.5.1: 1.3.5.1:““Here therefore we have three things to explain, Here therefore we have three things to explain, viz. viz. FirstFirst, The original impression [, The original impression [TT 1.3.5]. 1.3.5]. SecondlySecondly, The transition to the idea of the , The transition to the idea of the connected cause or effect [connected cause or effect [TT 1.3.6]. 1.3.6]. ThirdlyThirdly, , The nature and qualities of that idea.”The nature and qualities of that idea.”

Accordingly, Accordingly, TT 1.3.7 – “Of the nature of the 1.3.7 – “Of the nature of the idea or belief” – focuses on the idea [of the idea or belief” – focuses on the idea [of the effect effect BB] that we infer from the impression ] that we infer from the impression [of the cause[of the cause A A] in causal inference.] in causal inference.

4343

An Idea Associated with an ImpressionAn Idea Associated with an Impression

Since all belief about the unobserved Since all belief about the unobserved arises from causal inference (arises from causal inference (TT 1.3.2.3, 1.3.2.3, 1.3.6.7), and causal inference moves 1.3.6.7), and causal inference moves “from the impression to the idea”,“from the impression to the idea”,

““we may establish this as one part of the we may establish this as one part of the definition of an opinion or belief, definition of an opinion or belief, that ’tis an that ’tis an idea related to or associated with a present idea related to or associated with a present impressionimpression” (” (TT 1.3.6.15) 1.3.6.15)

Hume now goes on to investigate the Hume now goes on to investigate the nature of the associated idea.nature of the associated idea.

4444

““a new question unthought ofa new question unthought ofby philosophers” (by philosophers” (AA 17) 17)

Hume finds himself asking a profound Hume finds himself asking a profound question: “question: “Wherein consists the difference Wherein consists the difference betwixt incredulity and belief?betwixt incredulity and belief?” (” (TT 1.3.7.3). 1.3.7.3).

This anticipates Frege:This anticipates Frege:““two things must be distinguished in an two things must be distinguished in an indicative sentence: the content … and the indicative sentence: the content … and the assertion. The former is the thought … it is assertion. The former is the thought … it is possible to express the thought without laying possible to express the thought without laying it down as true.” (1918, p. 21).it down as true.” (1918, p. 21).

4545

A Manner of ConceptionA Manner of Conception

TT 1.2.6.4 argued that we have no separate 1.2.6.4 argued that we have no separate idea of existence; so that can’t make the idea of existence; so that can’t make the difference between belief and unbelief, and difference between belief and unbelief, and nor does any other idea (nor does any other idea (TT 1.3.7.2). 1.3.7.2).

If I believe proposition If I believe proposition PP, and you don’t, the , and you don’t, the same ideas must be involved, or it wouldn’t same ideas must be involved, or it wouldn’t be the same proposition (be the same proposition (TT 1.3.7.3-4 ). 1.3.7.3-4 ).

So the difference must lie in the So the difference must lie in the manner of manner of conceptionconception, or , or force and vivacityforce and vivacity ( (TT 1.3.7.5).1.3.7.5).

4646

The Definition of BeliefThe Definition of Belief

The initial sketch of belief asThe initial sketch of belief as““an idea related to or associated with a an idea related to or associated with a present impressionpresent impression” (” (TT 1.3.6.15) 1.3.6.15)

can now be filled out:can now be filled out:““An opinion, therefore, or belief may be most An opinion, therefore, or belief may be most accurately defin’ed, accurately defin’ed, A LIVELY IDEA RELATED TO A LIVELY IDEA RELATED TO OR ASSOCIATED WITH A PRESENT OR ASSOCIATED WITH A PRESENT

IMPRESSIONIMPRESSION.” (.” (TT 1.3.7.5) 1.3.7.5)

4747

What is “Force and Vivacity”?What is “Force and Vivacity”?

This isn’t entirely satisfactory:This isn’t entirely satisfactory:– A fictional story can be much more “forceful and A fictional story can be much more “forceful and

lively” than a dull historical account.lively” than a dull historical account.– ““Force and vivacity” isn’t a separate impression, Force and vivacity” isn’t a separate impression,

so how does it fit into Hume’s theory of ideas?so how does it fit into Hume’s theory of ideas?– If it’s part of the ideas believed, then how can If it’s part of the ideas believed, then how can

we distinguish between the belief in a dull red we distinguish between the belief in a dull red door and the imagination of a bright red door?door and the imagination of a bright red door?

– ““Manner of conception” suggests an Manner of conception” suggests an attitudeattitude change, rather than a change in the ideas.change, rather than a change in the ideas.

4848

Symptoms of UneaseSymptoms of Unease

In a paragraph added in the 1740 Appendix, In a paragraph added in the 1740 Appendix, Hume expresses discomfort with his account:Hume expresses discomfort with his account:

““An idea assented to An idea assented to feelsfeels different from a fictitious different from a fictitious idea … And this different feeling I endeavour to idea … And this different feeling I endeavour to explain by calling it a superior explain by calling it a superior forceforce, or , or vivacityvivacity, or , or soliditysolidity, or , or firmnessfirmness, or , or steadinesssteadiness. … ’tis . … ’tis impossible to explain perfectly this feeling or impossible to explain perfectly this feeling or manner of conception. We may make use of manner of conception. We may make use of words, that express something near it. But its true words, that express something near it. But its true and proper name is and proper name is beliefbelief, which is a term than , which is a term than every one sufficiently understands …” every one sufficiently understands …” ((TT 1.3.7.7) 1.3.7.7)

4949

““Of the causes of belief”Of the causes of belief”

TreatiseTreatise 1.3.8 draws a natural conclusion 1.3.8 draws a natural conclusion from two of Hume’s “discoveries”:from two of Hume’s “discoveries”:– TT 1.3.5.3 concluded that causal reasoning has 1.3.5.3 concluded that causal reasoning has

to start from an “impression” of the senses or to start from an “impression” of the senses or memory, distinguished from mere ideas of the memory, distinguished from mere ideas of the imagination by their “force and vivacity”. This imagination by their “force and vivacity”. This constitutes their “constitutes their “beliefbelief or or assentassent” (” (TT 1.3.5.7). 1.3.5.7).

– TT 1.3.7.5 concluded that something inferred by 1.3.7.5 concluded that something inferred by causal inference becomes a causal inference becomes a beliefbelief in virtue of in virtue of its force and vivacity.its force and vivacity.

5050

The Hydraulic Theory of BeliefThe Hydraulic Theory of Belief

““I wou’d willingly establish it as a general maxim in I wou’d willingly establish it as a general maxim in the science of human nature, the science of human nature, that when any that when any impression becomes present to us, it not only impression becomes present to us, it not only transports the mind to such ideas as are related to transports the mind to such ideas as are related to it, but likewise communicates to them a share of its it, but likewise communicates to them a share of its force and vivacityforce and vivacity.” (.” (TT 1.3.8.2) 1.3.8.2)

The remainder of The remainder of TT 1.3.8 gives various 1.3.8 gives various “experiments” to illustrate that the three “experiments” to illustrate that the three associational relations also convey force and associational relations also convey force and vivacity to the associated ideas, confirming this vivacity to the associated ideas, confirming this as a general phenomenon of human nature.as a general phenomenon of human nature.

5151

““Nothing But a Species of Sensation”Nothing But a Species of Sensation”

Hume sums up his theory of belief in Hume sums up his theory of belief in dramatic terms at dramatic terms at TT 1.3.8.12: 1.3.8.12:

““Thus all probable reasoning is nothing but a Thus all probable reasoning is nothing but a species of sensation. ’Tis not solely in poetry and species of sensation. ’Tis not solely in poetry and music, we must follow our taste and sentiment, music, we must follow our taste and sentiment, but likewise in philosophy. When I am convinc’d but likewise in philosophy. When I am convinc’d of any principle, ’tis only an idea, which strikes of any principle, ’tis only an idea, which strikes more strongly upon me. When I give the more strongly upon me. When I give the preference to one set of arguments above preference to one set of arguments above another, I do nothing but decide from my feeling another, I do nothing but decide from my feeling concerning the superiority of their influence.”concerning the superiority of their influence.”

5252

UP is (Typically) UnconsciousUP is (Typically) Unconscious

At At TT 1.3.8.13, Hume observes that: 1.3.8.13, Hume observes that:““the past experience, on which all our judgments the past experience, on which all our judgments concerning cause and effect depend, may concerning cause and effect depend, may operate on our mind in such an insensible operate on our mind in such an insensible manner as never to be taken notice of. … The manner as never to be taken notice of. … The custom operates before we have time for custom operates before we have time for reflection. The objects seem so inseparable, that reflection. The objects seem so inseparable, that we interpose not a moment’s delay in passing we interpose not a moment’s delay in passing from the one to the other. … the understanding from the one to the other. … the understanding or imagination [sic.] can draw inferences from or imagination [sic.] can draw inferences from past experience, without reflecting on it, much past experience, without reflecting on it, much more without forming any principle concerning it”more without forming any principle concerning it”

5353

Fast Forward to Fast Forward to TreatiseTreatise 1.3.14 1.3.14

Hume’s discussions in Hume’s discussions in TreatiseTreatise 1.3.9-13 1.3.9-13 mainly concern various types of rational and mainly concern various types of rational and irrational beliefs, and the psychological irrational beliefs, and the psychological mechanisms underlying them.mechanisms underlying them.

These sections are commonly ignored, but These sections are commonly ignored, but we’ll return to them briefly when considering we’ll return to them briefly when considering the nature of Hume’s “scepticism”.the nature of Hume’s “scepticism”.

The main narrative of The main narrative of TreatiseTreatise 1.3 resumes 1.3 resumes at Section 14, its culmination.at Section 14, its culmination.

4(d)4(d)

“Of the Idea of “Of the Idea of Necessary Necessary Connexion”Connexion”

5555

Reminder 1: The Idea of CauseReminder 1: The Idea of Cause

In In TreatiseTreatise I.3.2, Hume identifies the comp- I.3.2, Hume identifies the comp-onents of the idea of causation as onents of the idea of causation as contiguitycontiguity, , priority in timepriority in time (of (of AA to to BB), and ), and necessary necessary connexion connexion (see especially (see especially TT 1.3.2.11). 1.3.2.11).

At At TT 1.3.6.3, he identifies 1.3.6.3, he identifies constant conjunctionconstant conjunction (i.e. (i.e. regularregular succession) as the basis of our succession) as the basis of our ascription of necessary connexion.ascription of necessary connexion.

In the remainder of 1.3.6, he argues that causal In the remainder of 1.3.6, he argues that causal reasoning is founded on reasoning is founded on customcustom..

5656

Reminder 2: The Copy PrincipleReminder 2: The Copy Principle

According to (what is commonly called) According to (what is commonly called) Hume’s Hume’s Copy Principle Copy Principle ((TT 1.1.1.7), all our 1.1.1.7), all our simple ideas are copied from impressions.simple ideas are copied from impressions.

This provides “a new microscope” (This provides “a new microscope” (EE 7.4) for 7.4) for investigating the nature of ideas, by finding investigating the nature of ideas, by finding the corresponding impressions.the corresponding impressions.

In In TreatiseTreatise 1.3.14, he accordingly sets out to 1.3.14, he accordingly sets out to identify the impression from which the idea of identify the impression from which the idea of necessary connexion is copied.necessary connexion is copied.

See 1.3.14.1 for a preview of the argument.See 1.3.14.1 for a preview of the argument.

5757

Synonymy and DefinitionSynonymy and Definition

Hume begins his quest for the impression:Hume begins his quest for the impression:““I begin with observing that the terms of I begin with observing that the terms of efficacy, efficacy, agency, power, force, energy, necessity, connexionagency, power, force, energy, necessity, connexion, , and and productive qualityproductive quality, are all nearly synonimous; and , are all nearly synonimous; and therefore ’tis an absurdity to employ any of them in therefore ’tis an absurdity to employ any of them in defining the rest. By this observation we reject at defining the rest. By this observation we reject at once all the vulgar definitions, which philosophers once all the vulgar definitions, which philosophers have given of power and efficacy; and instead of have given of power and efficacy; and instead of searching for the idea in these definitions, must look searching for the idea in these definitions, must look for it in the impressions, from which it is originally for it in the impressions, from which it is originally deriv’d. If it be a compound idea, it must arise from deriv’d. If it be a compound idea, it must arise from compound impressions. If simple, from simple compound impressions. If simple, from simple impressions.” (impressions.” (TT 1.3.14.4)  1.3.14.4)

5858

Two PuzzlesTwo Puzzles

Why does Hume assume that “necessity”, Why does Hume assume that “necessity”, “power”, “force” etc. are virtual synonyms?“power”, “force” etc. are virtual synonyms?

Why does he assume that the idea of Why does he assume that the idea of “necessary connexion” is “necessary connexion” is simplesimple, and , and hence cannot be explicitily defined?hence cannot be explicitily defined?

Suggested solutionSuggested solution: Hume’s interest lies : Hume’s interest lies in in a single common elementa single common element of the of the relevant ideas, what we might call the relevant ideas, what we might call the element of element of consequentialityconsequentiality..

5959

A Third PuzzleA Third Puzzle

If If necessary connexionnecessary connexion is a key component is a key component of our idea of cause, then how can anyone of our idea of cause, then how can anyone even even believebelieve that causes could be less than that causes could be less than absolutely necessitating?absolutely necessitating?

““The vulgar … attribute the uncertainty of events to The vulgar … attribute the uncertainty of events to such an uncertainty in the causes as makes the latter such an uncertainty in the causes as makes the latter often fail of their usual influence …” (often fail of their usual influence …” (TT 1.3.12.5,  1.3.12.5, EE 8.13) 8.13)

This too is explained if the key idea is not This too is explained if the key idea is not necessitynecessity, but rather , but rather consequentiality:consequentiality: a a forceforce or or agencyagency need not be compelling. need not be compelling.

6060

““Power”, or “Necessary Connexion”?Power”, or “Necessary Connexion”?

In In TreatiseTreatise 1.3.14, Hume refers to the idea of 1.3.14, Hume refers to the idea of “power” or “efficacy” around three times more “power” or “efficacy” around three times more often than to the idea of “necessity” or often than to the idea of “necessity” or “necessary connexion”!“necessary connexion”!

My suggestion makes the former more My suggestion makes the former more appropriate, so why emphasise the latter in appropriate, so why emphasise the latter in the section’s title, and when summing up?the section’s title, and when summing up?

Suggested explanationSuggested explanation: The key result is to : The key result is to shed light on “liberty and necessity”, the shed light on “liberty and necessity”, the problem of free will (problem of free will (TT 2.3.1-2, 2.3.1-2, EE 8). 8).

6161

Refuting Locke and MalebrancheRefuting Locke and Malebranche

Locke is wrong to suggest we can get the Locke is wrong to suggest we can get the idea of power from “new productions in idea of power from “new productions in matter” (matter” (TT 1.3.14.5). 1.3.14.5).

Malebranche is right to deny that “the secret Malebranche is right to deny that “the secret force and energy of causes” can be found in force and energy of causes” can be found in bodies (bodies (TT 1.3.14.7). 1.3.14.7).

But the Copy Principle refutes Malebranche’s But the Copy Principle refutes Malebranche’s claim that we acquire the idea of an “active claim that we acquire the idea of an “active principle” from our idea of God principle” from our idea of God (T(T 1.3.14.10) 1.3.14.10)..

6262

No Idea from Single InstancesNo Idea from Single Instances

Powers cannot be found among the known or Powers cannot be found among the known or perceived properties of matter (perceived properties of matter (TT 1.3.14.7-11). 1.3.14.7-11).

Nor among the properties of mind (added in Nor among the properties of mind (added in the the AppendixAppendix of 1740, of 1740, TT 1.3.14.12, SB 632-3). 1.3.14.12, SB 632-3).

We cannot find any We cannot find any specificspecific impression of impression of power in these various sources, hence they power in these various sources, hence they cannot possibly yield any cannot possibly yield any generalgeneral idea of idea of power either (power either (TT 1.3.14.13; cf. the theory of 1.3.14.13; cf. the theory of “general or abstract ideas” of 1.1.7).“general or abstract ideas” of 1.1.7).

6363

Repeated InstancesRepeated Instances

The actual source of the key impression is The actual source of the key impression is revealed when we turn to revealed when we turn to repeatedrepeated instances instances of observed conjunctions of “objects”. In of observed conjunctions of “objects”. In these circumstances,these circumstances,

“… “… we immediately conceive a connexion betwixt we immediately conceive a connexion betwixt them, and … draw an inference from one to them, and … draw an inference from one to another. This multiplicity of resembling instances, another. This multiplicity of resembling instances, therefore, constitutes the very essence of power or therefore, constitutes the very essence of power or connexion, and is the source, from which the idea connexion, and is the source, from which the idea of it arises.” (of it arises.” (TT 1.3.14.16) 1.3.14.16)

6464

An An InternalInternal Impression Impression

Repeated instances supply no new Repeated instances supply no new impression impression from the objectsfrom the objects; to find the ; to find the elusive impression of power we must look elusive impression of power we must look inside ourselves to the habitual transition of inside ourselves to the habitual transition of the mind (i.e. the operation of custom).the mind (i.e. the operation of custom).

TT 1.3.6.3 anticipated this result: 1.3.6.3 anticipated this result:““Perhaps ’twill appear in the end, that the Perhaps ’twill appear in the end, that the necessary connexion depends on the necessary connexion depends on the inference, instead of the inference’s depending inference, instead of the inference’s depending on the necessary connexionon the necessary connexion.”.”

6565

Is the Impression a Is the Impression a FeelingFeeling? ?

““This connexion … which we This connexion … which we feelfeel in the mind, this in the mind, this customary transition of the imagination from one customary transition of the imagination from one object to its usual attendant, is the sentiment or object to its usual attendant, is the sentiment or impression, from which we form the idea of power impression, from which we form the idea of power or necessary connexion.” (or necessary connexion.” (EE 7.28). 7.28).

Stroud and others take the impression to be a Stroud and others take the impression to be a feelingfeeling of compulsion that accompanies the of compulsion that accompanies the operation of customary inference.operation of customary inference.

But Hume’s own arguments seem to rule out the But Hume’s own arguments seem to rule out the possibility that mere feelings could be the source possibility that mere feelings could be the source of the idea (of the idea (TT 1.3.14.121.3.14.12, , EE 7.15 n. 13). 7.15 n. 13).

6666

Is “Determination of theIs “Determination of theMind” an Mind” an Impression?Impression?

Why does Hume equate Why does Hume equate inferenceinference from from AA to to BB – a transition of thought from – a transition of thought from AA to to BB, , with with anotheranother, third, “perception”?, third, “perception”?

““This determination is the only effect of the resemblance; This determination is the only effect of the resemblance; and therefore must be the same with power or efficacy, and therefore must be the same with power or efficacy, whose idea is deriv’d from the resemblance. … Necessity, whose idea is deriv’d from the resemblance. … Necessity, then, is … nothing but an internal impression of the mind, then, is … nothing but an internal impression of the mind, or a determination to carry our thoughts from one object to or a determination to carry our thoughts from one object to another.another.” (” (TT 1.3.14.20) 1.3.14.20)

Hume needs an “impression” to satisfy his Copy Hume needs an “impression” to satisfy his Copy Principle, but this may be misleading …Principle, but this may be misleading …

6767

Reflexive Awareness of InferenceReflexive Awareness of Inference

ConsequentialityConsequentiality may be the key here … may be the key here …

InferenceInference isis genuinely consequential: genuinely consequential:““that inference of the understanding, which is the only that inference of the understanding, which is the only connexion, that we can have any comprehension of” connexion, that we can have any comprehension of” ((EE 8.25) 8.25)

Hume should be taken literally: the source of the Hume should be taken literally: the source of the idea is the idea is the reflexive awareness of making causal reflexive awareness of making causal inferenceinference, and , and notnot a feeling. a feeling.

This awareness is very dubiously an “impression”; This awareness is very dubiously an “impression”; here Hume’s theory of the mind is far too crude in here Hume’s theory of the mind is far too crude in limiting our awareness to ideas and impressions.limiting our awareness to ideas and impressions.

6868

Necessity in the Mind, not in ObjectsNecessity in the Mind, not in Objects

““[customary inference] is the essence of necessity. [customary inference] is the essence of necessity. … necessity is something, that exists in the mind, not … necessity is something, that exists in the mind, not in objects; nor is it possible for us ever to form the in objects; nor is it possible for us ever to form the most distant idea of it, consider’d as a quality in most distant idea of it, consider’d as a quality in bodies. … necessity is nothing but that bodies. … necessity is nothing but that determination of the thought to pass from causes to determination of the thought to pass from causes to effects and from effects to causes, according to their effects and from effects to causes, according to their experienc’d union.” (experienc’d union.” (TT 1.3.14.22) 1.3.14.22)

““When we say, therefore, that one object is When we say, therefore, that one object is connected with another, we mean only, that they connected with another, we mean only, that they have acquired a connexion in our thought, and give have acquired a connexion in our thought, and give rise to this inference …” (rise to this inference …” (EE 7.28) 7.28)

6969

Hume’s Anti-RealismHume’s Anti-Realism

Hume is not saying that there Hume is not saying that there isis some kind of full-some kind of full-blooded “thick” necessity, but that it applies only blooded “thick” necessity, but that it applies only to events in the mind. Rather …to events in the mind. Rather …

We find ourselves inferring from We find ourselves inferring from AA to to BB, and this , and this consequential relation is consequential relation is all that we can all that we can understandunderstand by “necessity”. We can’t even make by “necessity”. We can’t even make sense of any more “full-blooded” necessity.sense of any more “full-blooded” necessity.

This seems incredible to us because “the mind This seems incredible to us because “the mind has a great propensity to spread itself on external has a great propensity to spread itself on external objects, and to conjoin with them any internal objects, and to conjoin with them any internal impressions, which they occasion” (impressions, which they occasion” (TT 1.3.14.25). 1.3.14.25).

7070

An Outrageous Conclusion …An Outrageous Conclusion …

““But tho’ this be the only reasonable account we can But tho’ this be the only reasonable account we can give of necessity … I doubt not that my sentiments give of necessity … I doubt not that my sentiments will be treated by many as extravagant and ridiculous. will be treated by many as extravagant and ridiculous. What! the efficacy of causes lie in the determination What! the efficacy of causes lie in the determination of the mind! As if causes did not operate entirely of the mind! As if causes did not operate entirely independent of the mind, and wou’d not continue their independent of the mind, and wou’d not continue their operation, even tho’ there was no mind existent to operation, even tho’ there was no mind existent to contemplate them … to remove [power] from all contemplate them … to remove [power] from all causes, and bestow it on a being, that is no ways causes, and bestow it on a being, that is no ways related to the cause or effect, but by perceiving them, related to the cause or effect, but by perceiving them, is a gross absurdity, and contrary to the most certain is a gross absurdity, and contrary to the most certain principles of human reason.” (principles of human reason.” (TT 1.3.14.26) 1.3.14.26)

7171

… … Which Hume Defends!Which Hume Defends!

““I can only reply to all these arguments, that the case I can only reply to all these arguments, that the case is here much the same, as if a blind man shou’d is here much the same, as if a blind man shou’d pretend to find a great many absurdities in the pretend to find a great many absurdities in the supposition, that the colour of scarlet is not the same supposition, that the colour of scarlet is not the same with the sound of a trumpet, nor light the same with with the sound of a trumpet, nor light the same with solidity. If we really have no idea of a power or solidity. If we really have no idea of a power or efficacy in any object, or of any real connexion efficacy in any object, or of any real connexion betwixt causes and effects, ’twill be to little purpose to betwixt causes and effects, ’twill be to little purpose to prove, that an efficacy is necessary in all operations. prove, that an efficacy is necessary in all operations. We do not understand our own meaning in talking so, We do not understand our own meaning in talking so, but ignorantly confound ideas, which are entirely but ignorantly confound ideas, which are entirely distinct from each other.” (distinct from each other.” (TT 1.3.14.27) 1.3.14.27)

7272

Objective Causes, in a Sense …Objective Causes, in a Sense …

““As to what may be said, that the operations of As to what may be said, that the operations of nature are independent of our thought and nature are independent of our thought and reasoning, I allow it; and accordingly have reasoning, I allow it; and accordingly have observ’d, that objects bear to each other the observ’d, that objects bear to each other the relations of contiguity and succession; that like relations of contiguity and succession; that like objects may be observ’d in several instances to objects may be observ’d in several instances to have like relations; and that all this is have like relations; and that all this is independent of, and antecedent to the operations independent of, and antecedent to the operations of the understanding.” (of the understanding.” (TT 1.3.14.28) 1.3.14.28)

There is an objective and a subjective side There is an objective and a subjective side to our idea of power or necessity; hence to our idea of power or necessity; hence two definitions of “cause”.two definitions of “cause”.

7373

Two “Definitions of Cause”Two “Definitions of Cause”

Hume’s main discussions of “the idea of Hume’s main discussions of “the idea of necessary connexion” (necessary connexion” (TreatiseTreatise 1.3.14 and 1.3.14 and EnquiryEnquiry 7) both culminate with two 7) both culminate with two “definitions of cause”.“definitions of cause”.

The first definition is based on The first definition is based on regular regular successionsuccession of the “cause” of the “cause” AA followed by followed by “effect” “effect” BB (plus contiguity in the (plus contiguity in the TreatiseTreatise).).

The second definition is based on the The second definition is based on the mind’s tendency to mind’s tendency to inferinfer BB from from AA..

7474

““There may two definitions be given of this relation, There may two definitions be given of this relation, which are only different, by their presenting a different which are only different, by their presenting a different view of the same object … We may define a view of the same object … We may define a CAUSECAUSE to to be ‘An object precedent and contiguous to another, and be ‘An object precedent and contiguous to another, and where all the objects resembling the former are plac’d in where all the objects resembling the former are plac’d in like relations of precedency and contiguity to those like relations of precedency and contiguity to those objects, which resemble the latter.’ If this definition be objects, which resemble the latter.’ If this definition be esteem’d defective, because drawn from objects foreign esteem’d defective, because drawn from objects foreign to the cause, we may substitute this other definition in its to the cause, we may substitute this other definition in its place, place, viz.viz. ‘A ‘A CAUSECAUSE is an object precedent and is an object precedent and contiguous to another, and so united with it, that the idea contiguous to another, and so united with it, that the idea of the one determines the mind to form the idea of the of the one determines the mind to form the idea of the other, and the impression of the one to form a more lively other, and the impression of the one to form a more lively idea of the other.’ Shou’d this definition also be rejected idea of the other.’ Shou’d this definition also be rejected for the same reason, I know no other remedy …”for the same reason, I know no other remedy …”

((TT 1.3.14.31)1.3.14.31)

7575

The Confused Vulgar Idea of PowerThe Confused Vulgar Idea of Power

““as we as we feelfeel a customary connexion … we transfer that a customary connexion … we transfer that feeling to the objects; as nothing is more usual than to feeling to the objects; as nothing is more usual than to apply to external objects every internal sensation, apply to external objects every internal sensation, which they occasion” (which they occasion” (EE 7.29 n. 17) 7.29 n. 17)

At TAt T 1.3.14.25 n. 32, referring to 1.4.5.13, this is comp- 1.3.14.25 n. 32, referring to 1.4.5.13, this is comp-ared to our propensity to objectify taste impressions: ared to our propensity to objectify taste impressions: “All this absurdity proceeds from our endeavouring to “All this absurdity proceeds from our endeavouring to bestow a place on what is utterly incapable of it”.bestow a place on what is utterly incapable of it”.

Necessity involves “the same propensity” (Necessity involves “the same propensity” (TT 1.3.14.25). 1.3.14.25).

““the sentiment of the sentiment of nisusnisus or endeavour” also “enters very or endeavour” also “enters very much into” the vulgar idea (much into” the vulgar idea (EE 7.15 n. 13, 7.29 n. 17). 7.15 n. 13, 7.29 n. 17).

7676

The More Precise Humean IdeaThe More Precise Humean Idea

“’“’tis probable, that these expressions do here lose their tis probable, that these expressions do here lose their true meaning by being true meaning by being wrong apply’dwrong apply’d, than that they , than that they never have any meaning”never have any meaning” ( (TT 1.3.14.14). 1.3.14.14).

Hume takes his analysis and definitions to Hume takes his analysis and definitions to vindicatevindicate a a more precise idea of power, by revealing that there is a more precise idea of power, by revealing that there is a bona fidebona fide impression from which it is derived. impression from which it is derived.

He seems to be saying we should apply that idea He seems to be saying we should apply that idea according to the first definition (constant conjunction), according to the first definition (constant conjunction), and understand its application as implying willingness to and understand its application as implying willingness to draw inferences accordingly (as in the second definition).draw inferences accordingly (as in the second definition).

This is close to a kind of “quasi-realism” (Blackburn’s This is close to a kind of “quasi-realism” (Blackburn’s term), parallel with Hume’s moral theory.term), parallel with Hume’s moral theory.

7777

““Corollaries” of the DefinitionsCorollaries” of the Definitions

““All causes are of the same kind … For the same All causes are of the same kind … For the same reason we must reject the distinction betwixt reason we must reject the distinction betwixt causecause and and occasionoccasion … If constant conjunction be imply’d in what … If constant conjunction be imply’d in what we call occasion, ’tis a real cause. If not, ’tis no relation we call occasion, ’tis a real cause. If not, ’tis no relation at all …” (at all …” (TT 1.3.14.32) 1.3.14.32)

““there is but one kind of there is but one kind of necessitynecessity … and … the common … and … the common distinction betwixt distinction betwixt moralmoral and and physicalphysical necessity is necessity is without any foundation in nature.” (without any foundation in nature.” (TT 1.3.14.33) 1.3.14.33)

It is now easy to see why the Causal Maxim of It is now easy to see why the Causal Maxim of TT 1.3.3 is 1.3.3 is not intuitively or demonstratively certain. (not intuitively or demonstratively certain. (TT 1.3.14.35) 1.3.14.35)

““we can never have reason to believe that any object we can never have reason to believe that any object exists, of which we cannot form an idea.” (exists, of which we cannot form an idea.” (TT 1.3.14.36) 1.3.14.36)

4(e)4(e)

Understanding Understanding Hume on Hume on CausationCausation

7979

The “New Hume”The “New Hume”

Hume has generally been read as denying the Hume has generally been read as denying the existence of any causal “power” or “necessity” existence of any causal “power” or “necessity” going beyond his two definitions (i.e. any going beyond his two definitions (i.e. any upper-case Causation or “thick connexions”).upper-case Causation or “thick connexions”).

The “New Hume” is the view of John Wright, The “New Hume” is the view of John Wright, Edward Craig, Galen Strawson and others that Edward Craig, Galen Strawson and others that Hume is instead a “Causal Realist”.Hume is instead a “Causal Realist”.

Their most persuasive argument:Their most persuasive argument: Hume’s texts Hume’s texts show him to be taking causation, causal power show him to be taking causation, causal power and causal necessity very seriously …and causal necessity very seriously …

8080

““Sceptical Realism”Sceptical Realism”

John Wright coined the term “Sceptical John Wright coined the term “Sceptical Realism” for this point of view:Realism” for this point of view:

– RealismRealism: Causation in things goes beyond : Causation in things goes beyond functional relations of regular succession, functional relations of regular succession, involving a full-blooded necessity which, if we involving a full-blooded necessity which, if we knew it, would license a priori inference.knew it, would license a priori inference.

– ScepticalSceptical: In so far as Causation goes : In so far as Causation goes beyond what is captured by Hume’s two beyond what is captured by Hume’s two definitions, it cannot be known or understood.definitions, it cannot be known or understood.

8181

Hume’s Advocacy of Causal ScienceHume’s Advocacy of Causal Science

Hume seems in general to have a very Hume seems in general to have a very positive attitude towards causal science:positive attitude towards causal science:

a)a) He says that causation is the basis of all He says that causation is the basis of all empirical inference;empirical inference;

b)b) He proposes “rules by which to judge of He proposes “rules by which to judge of causes and effects”;causes and effects”;

c)c) He talks of “secret powers”;He talks of “secret powers”;

d)d) He advocates a search for hidden causes He advocates a search for hidden causes underlying inconstant phenomena.underlying inconstant phenomena.

8282

(a) (a) The Basis of Empirical InferenceThe Basis of Empirical Inference

““The only connexion or relation of objects, The only connexion or relation of objects, which can lead us beyond the immediate which can lead us beyond the immediate impressions of our memory and senses, is impressions of our memory and senses, is that of cause and effect …” (that of cause and effect …” (TT 1.3.6.7) 1.3.6.7)

“’“’Tis evident, that all reasonings concerning Tis evident, that all reasonings concerning matter of factmatter of fact are founded on the relation of are founded on the relation of cause and effect” (cause and effect” (AA 8) 8)

““All reasonings concerning matter of fact All reasonings concerning matter of fact seem to be founded on the relation of Cause seem to be founded on the relation of Cause and Effect.” (and Effect.” (EE 4.4, cf.  4.4, cf. EE 7.29) 7.29)

8383

(b)(b) The Rules of The Rules of TreatiseTreatise 1.3.15 1.3.15

““Since therefore ’tis possible for all objects to Since therefore ’tis possible for all objects to become causes or effects to each other, it may become causes or effects to each other, it may be proper to fix some general rules, by which be proper to fix some general rules, by which we may know when they really are so.” we may know when they really are so.” ((TT 1.3.15.1) 1.3.15.1)

““[Phenomena] in nature [are] compounded and [Phenomena] in nature [are] compounded and modify’d by so many different circumstances, modify’d by so many different circumstances, that … we must carefully separate whatever is that … we must carefully separate whatever is superfluous, and enquire by new experiments, if superfluous, and enquire by new experiments, if every particular circumstance of the first every particular circumstance of the first experiment was essential to it” (experiment was essential to it” (TT 1.3.15.11) 1.3.15.11)

8484

(c)(c) Hume’s Talk of “Secret Powers” Hume’s Talk of “Secret Powers”

Most prominent in Most prominent in EnquiryEnquiry 4-5 4-5::– ““the ultimate cause of any natural operation … the ultimate cause of any natural operation …

that power, which produces any … effect in the that power, which produces any … effect in the universe … the causes of these general causes universe … the causes of these general causes … ultimate springs and principles” (… ultimate springs and principles” (EE 4.12); 4.12);

– ““the secret powers [of bodies] … those powers the secret powers [of bodies] … those powers and principles on which the influence of … and principles on which the influence of … objects entirely depends” (objects entirely depends” (EE 4.16); 4.16);

– ““those powers and forces, on which this regular those powers and forces, on which this regular course and succession of objects totally course and succession of objects totally depends” (depends” (EE 5.22); 5.22);

8585

Necessity as Essential to CausationNecessity as Essential to Causation

““Power” is a term from the same family – Power” is a term from the same family – derived from the same impression – as derived from the same impression – as “necessity”, which Hume sees as an “necessity”, which Hume sees as an essential part of our idea of causation:essential part of our idea of causation:– ““According to my definitions, necessity makes According to my definitions, necessity makes

an essential part of causation” (an essential part of causation” (TT 2.3.1.18, cf.  2.3.1.18, cf. also also 1.3.2.11, 1.3.6.3).1.3.2.11, 1.3.6.3).

– ““Necessity may be defined two ways, conform-Necessity may be defined two ways, conform-ably to the two definitions of ably to the two definitions of causecause, of which it , of which it makes an essential part.” (makes an essential part.” (EE 8.27, cf. 8.25) 8.27, cf. 8.25)

8686

(d)(d) The Search for Hidden Causes The Search for Hidden Causes

““philosophers, observing, that, almost in every philosophers, observing, that, almost in every part of nature, there is contained a vast variety part of nature, there is contained a vast variety of springs and principles, which are hid, by of springs and principles, which are hid, by reason of their minuteness or remoteness, find, reason of their minuteness or remoteness, find, that it is at least possible the contrariety of that it is at least possible the contrariety of events may … proceed … from the secret events may … proceed … from the secret operation of contrary causes. ... they remark, operation of contrary causes. ... they remark, that, upon an exact scrutiny, a contrariety of that, upon an exact scrutiny, a contrariety of effects always betrays a contrariety of causes, effects always betrays a contrariety of causes, and proceeds from their mutual opposition.”and proceeds from their mutual opposition.”(E 8.13, copied from (E 8.13, copied from TT 1.3.12.5) 1.3.12.5)

8787

Causal Science and Causal RealismCausal Science and Causal Realism

We have seen that Hume indeed takes We have seen that Hume indeed takes causal sciencecausal science very seriously. All very seriously. All science must be causal; causal relations science must be causal; causal relations can be established by rules; explanation can be established by rules; explanation involves reference to secret powers; and involves reference to secret powers; and we should search for hidden causes.we should search for hidden causes.

But the presumption that this implies But the presumption that this implies Casual RealismCasual Realism that goes beyond the that goes beyond the two definitions can be challenged …two definitions can be challenged …

8888

Hume’s Anti-Realism: an Initial CaseHume’s Anti-Realism: an Initial Case

1.1. Berkeley’s example proves that a positive Berkeley’s example proves that a positive attitude to science need not imply Causal attitude to science need not imply Causal Realism. Hume’s attitude seems quite similar.Realism. Hume’s attitude seems quite similar.

2.2. Hume’s argument concerning the origin of the Hume’s argument concerning the origin of the idea of necessary connexion, in idea of necessary connexion, in TreatiseTreatise 1.3.14 1.3.14 and and EnquiryEnquiry 7, has standardly been read as 7, has standardly been read as implying that he is a Causal anti-Realist. implying that he is a Causal anti-Realist.

3.3. An important footnote connects the power An important footnote connects the power references in references in EnquiryEnquiry 4-5 with the apparently 4-5 with the apparently anti-Realist argument of anti-Realist argument of Enquiry Enquiry 7, in such a 7, in such a way as to undermine their apparent force.way as to undermine their apparent force.

8989

1.1. Berkeley’s Instrumentalism Berkeley’s Instrumentalism

… … the difference there is betwixt natural philosophers the difference there is betwixt natural philosophers and other men, with regard to their knowledge of the and other men, with regard to their knowledge of the phenomenaphenomena, … consists, not in an exacter knowledge , … consists, not in an exacter knowledge of the efficient cause that produces them, for that can of the efficient cause that produces them, for that can be no other than the be no other than the will of a spiritwill of a spirit, but only in a greater , but only in a greater largeness of comprehension, whereby analogies, largeness of comprehension, whereby analogies, harmonies, and agreements are discovered in the harmonies, and agreements are discovered in the works of Nature, and the particular effects explained, works of Nature, and the particular effects explained, that is, reduced to general rules … which rules that is, reduced to general rules … which rules grounded on the analogy, and uniformness observed grounded on the analogy, and uniformness observed in the production of natural effects (in the production of natural effects (PrinciplesPrinciples i 105) i 105)

9090

Science as SimplificationScience as Simplification

““the utmost effort of human reason is, to reduce the the utmost effort of human reason is, to reduce the principles, productive of natural phaenomena, to a principles, productive of natural phaenomena, to a greater simplicity, and to resolve the many parti-greater simplicity, and to resolve the many parti-cular effects into a few general causes, by means cular effects into a few general causes, by means of reasonings from analogy, experience, and of reasonings from analogy, experience, and observation. But as to the causes of these general observation. But as to the causes of these general causes, we should in vain attempt their discovery causes, we should in vain attempt their discovery … and we may esteem ourselves sufficiently … and we may esteem ourselves sufficiently happy, if, by accurate enquiry and reasoning, we happy, if, by accurate enquiry and reasoning, we can trace up the particular phaenomena to, or near can trace up the particular phaenomena to, or near to, … general principles.” (to, … general principles.” (EE 4.12, cf.  4.12, cf. TT intro 8) intro 8)

9191

2.2. An Argument for Anti-Realism An Argument for Anti-Realism

Hume’s entire argument is structured around Hume’s entire argument is structured around the Copy Principle quest for an impression.the Copy Principle quest for an impression.

The Principle is a tool for deciding questions of The Principle is a tool for deciding questions of meaningmeaning ( (TT 1.1.6.1, 1.1.6.1, AA 7, 7, EE 2.9). 2.9).

He aims to find causal terms’ He aims to find causal terms’ meaningmeaning or or signif-signif-icanceicance ( (TT 1.3.14.14 1.3.14.14 && 27, 27, AA 26, 26, EE 7.3, 26 7.3, 26 && 28). 28).

When the When the subjectivesubjective impression is identified, impression is identified, the apparently anti-Realist implication is stated.the apparently anti-Realist implication is stated.

The discussion culminates with two The discussion culminates with two definitionsdefinitions of “cause”, incorporating this anti-Realism.of “cause”, incorporating this anti-Realism.

9292

3.3. Kames and a Footnote Kames and a Footnote

Kames (1751) quoted Hume’s references Kames (1751) quoted Hume’s references to powers in the to powers in the EnquiryEnquiry (at 4.16) (at 4.16) against against him, as evidence of inconsistency; they him, as evidence of inconsistency; they knew each other well and swapped knew each other well and swapped manuscripts prior to publication.manuscripts prior to publication.

In 1750 Hume added a footnote to In 1750 Hume added a footnote to EE 4.16: 4.16:– ““* The word, Power, is here used in a loose * The word, Power, is here used in a loose

and popular sense. The more accurate and popular sense. The more accurate explication of it would give additional evidence explication of it would give additional evidence to this argument. See Sect. 7.to this argument. See Sect. 7.””

9393

Quantitative ForcesQuantitative ForcesIn the In the EnquiryEnquiry, Hume is clear that mechanics , Hume is clear that mechanics involves involves forces:forces: theoretical entities that can be theoretical entities that can be quantified and enter into equations describing quantified and enter into equations describing objects’ behaviour. (e.g. objects’ behaviour. (e.g. EE 4.12-13) 4.12-13)

““Force” is in the same family as “power” etc.Force” is in the same family as “power” etc.

This, rather than Causal Realism, explains the This, rather than Causal Realism, explains the EnquiryEnquiry’s prominent “power” language.’s prominent “power” language.

EE 7.25n and 7.25n and EE 7.29n both suggest an attitude to 7.29n both suggest an attitude to such forces corresponding exactly to the anti-such forces corresponding exactly to the anti-realist spirit of realist spirit of EnquiryEnquiry 7. Forces are to be treated 7. Forces are to be treated instrumentallyinstrumentally (cf. Newton and Berkeley). (cf. Newton and Berkeley).

9494

Why Two Definitions?Why Two Definitions?

The argument of T 1.3.14 and E 7 ends, The argument of T 1.3.14 and E 7 ends, notoriously, with notoriously, with twotwo definitions of cause: definitions of cause:

– The first definition is based on The first definition is based on regular regular successionsuccession of the “cause” of the “cause” AA followed by “effect” followed by “effect” BB (plus contiguity in the (plus contiguity in the TreatiseTreatise).).

– The second definition is based on the mind’s The second definition is based on the mind’s tendency to tendency to inferinfer BB from from AA..

These don’t coincide: constant conjunctions These don’t coincide: constant conjunctions can be unseen, and we can (mistakenly) can be unseen, and we can (mistakenly) infer when the conjunctions are inconstant.infer when the conjunctions are inconstant.

9595

To make sense of the definitions, we should not To make sense of the definitions, we should not assume that they are intended to specify assume that they are intended to specify necessary and sufficient conditions.necessary and sufficient conditions.

Hume’s conception of Hume’s conception of meaningmeaning, associated with , associated with his Copy Principle, suggests a different view. The his Copy Principle, suggests a different view. The meaning of causal necessity can only be meaning of causal necessity can only be understood through the impression from which its understood through the impression from which its idea is derived: idea is derived: reflexive awareness of our own reflexive awareness of our own inferential behaviourinferential behaviour in response to observed in response to observed constant conjunctions.constant conjunctions.

The second definition, accordingly, specifies a The second definition, accordingly, specifies a paradigm case in which we experience this paradigm case in which we experience this impression and thus can acquire the idea.impression and thus can acquire the idea.

9696

Nothing in Hume’s theory requires that, Nothing in Hume’s theory requires that, having having once acquired the ideaonce acquired the idea, we must restrict its , we must restrict its application to those paradigm cases that application to those paradigm cases that characteristically generate it.characteristically generate it.

Indeed his advocacy of “rules by which to judge of Indeed his advocacy of “rules by which to judge of causes and effects” etc. implies that he must think causes and effects” etc. implies that he must think we can go beyond these cases by we can go beyond these cases by systematisingsystematising our application of the idea (cf. his discussion of our application of the idea (cf. his discussion of the “system of realities” at the “system of realities” at TT 1.3.9.3‑5) 1.3.9.3‑5) ..

Accordingly the two definitions can be seen as Accordingly the two definitions can be seen as complementarycomplementary rather than conflicting. The rather than conflicting. The second identifies the relevant idea; the first second identifies the relevant idea; the first specifies the criterion for applying it.specifies the criterion for applying it.

9797

There is a parallel case in Hume’s treatment of There is a parallel case in Hume’s treatment of virtuevirtue or or personal meritpersonal merit in the in the Moral EnquiryMoral Enquiry. . Here again he gives two definitions:Here again he gives two definitions:– ““PERSONAL MERITPERSONAL MERIT consists altogether in the consists altogether in the

possession of mental qualities, possession of mental qualities, usefuluseful or or agreeableagreeable to the to the person himselfperson himself or to or to othersothers. … . … The preceding … definition The preceding … definition … …” (” (MM 9.1, 9.12) 9.1, 9.12)

– ““[My] hypothesis … defines virtue to be [My] hypothesis … defines virtue to be whatever mental action or quality gives to a whatever mental action or quality gives to a spectator the pleasing sentiment of spectator the pleasing sentiment of approbationapprobation; …” (; …” (MM Appendix 1.10) Appendix 1.10)

Again we have a characteristic idea, whose Again we have a characteristic idea, whose application is then to be systematised.application is then to be systematised.

9898

This understanding of the paired definitions This understanding of the paired definitions tells strongly in an anti-Realist direction. For it tells strongly in an anti-Realist direction. For it suggests that the system of causes, like the suggests that the system of causes, like the system of virtues, is essentially being read system of virtues, is essentially being read intointo the world rather than being read the world rather than being read offoff it. it.

We thus have a process of systematisation in We thus have a process of systematisation in which our natural judgement, refined and which our natural judgement, refined and applied more systematically in accordance applied more systematically in accordance with the relevant rules, “raises, in a manner, a with the relevant rules, “raises, in a manner, a new creation”, by “gilding or staining natural new creation”, by “gilding or staining natural objects with the colours, borrowed from objects with the colours, borrowed from internal sentiment” (internal sentiment” (MM Appendix 1.21). Appendix 1.21).

4(f)4(f)

The Point of The Point of Hume’s Hume’s

Analysis of Analysis of CausationCausation

100100

Hume’s Use of his Two DefinitionsHume’s Use of his Two Definitions

If we search for subsequent paragraphs in the If we search for subsequent paragraphs in the TreatiseTreatise that mention the definition of “cause”, that mention the definition of “cause”, “power” or “necessity”, we find just three, at“power” or “necessity”, we find just three, atTT 1.4.5.31, 2.3.1.18, and 2.3.2.4 1.4.5.31, 2.3.1.18, and 2.3.2.4

If we search instead for “constant conjunction” or If we search instead for “constant conjunction” or “constant union”, we find mainly “constant union”, we find mainly T T 1.4.5.30-33, 1.4.5.30-33, 2.3.1.416, and 2.3.2.4 2.3.1.416, and 2.3.2.4 (T(T 1.4.1.2 and 1.4.3.2 also 1.4.1.2 and 1.4.3.2 also mention “constant union” brieflymention “constant union” briefly).).

Similar searches in the Similar searches in the EnquiryEnquiry point very point very clearly clearly to Section 8 (10.5 is the only other).to Section 8 (10.5 is the only other).

101101

Causation and the MindCausation and the Mind

Hume is especially keen to establish causality Hume is especially keen to establish causality and necessity in respect of the mind:and necessity in respect of the mind:– In principle, matter could be the cause of thought In principle, matter could be the cause of thought

(T (T 1.4.5,1.4.5, “Of the Immateriality of the Soul”) “Of the Immateriality of the Soul”)

– The “doctrine of necessity” applies as much to the The “doctrine of necessity” applies as much to the mental world as to the physical worldmental world as to the physical world(T(T 2.3.1-2 and 2.3.1-2 and EE 8 8 “Of Liberty and Necessity”) “Of Liberty and Necessity”)

Both arguments crucially turn on the claim that Both arguments crucially turn on the claim that there is nothing to causal necessity beyond there is nothing to causal necessity beyond the two definitions …the two definitions …

102102

Of the Immateriality of the SoulOf the Immateriality of the Soul

The standard anti-materialist argument The standard anti-materialist argument insists that material changes cannot cause insists that material changes cannot cause thought, because the two are so different.thought, because the two are so different.– “… “… and yet nothing in the world is more easy than and yet nothing in the world is more easy than

to refute it. We need only to reflect on what has to refute it. We need only to reflect on what has been prov’d at large … that to consider the matter been prov’d at large … that to consider the matter a prioria priori, any thing may produce any thing, and , any thing may produce any thing, and that we shall never discover a reason, why any that we shall never discover a reason, why any object may or may not be the cause of any other, object may or may not be the cause of any other, however great, or however little the resemblance however great, or however little the resemblance may be between themmay be between them ”” (T(T 1.4.5.30 1.4.5.30))

103103

Hume then goes further to insist that material Hume then goes further to insist that material motion motion is indeedis indeed found to be the cause of thought: found to be the cause of thought:

– ““we find … by experience, that they are constantly we find … by experience, that they are constantly united; which being united; which being all the circumstances, that all the circumstances, that enter into the idea of cause and effectenter into the idea of cause and effect … we may … we may certainlycertainly conclude, that motion may be, and conclude, that motion may be, and actually isactually is, the cause of thought and perception.” , the cause of thought and perception.” ((TT 1.4.5.30, my emphasis) 1.4.5.30, my emphasis)

– ““as as the constant conjunction of objects constitutes the constant conjunction of objects constitutes the very essence of cause and effectthe very essence of cause and effect, matter and , matter and motion may often be regarded as the causes of motion may often be regarded as the causes of thought, as far as we have any notion of that thought, as far as we have any notion of that relation.” (relation.” (TT 1.4.5.33, my emphasis) 1.4.5.33, my emphasis)

104104

Of Liberty and NecessityOf Liberty and Necessity

Hume’s argument that the same necessity is Hume’s argument that the same necessity is applicable to the moral and physical realms applicable to the moral and physical realms depends on taking our understanding of depends on taking our understanding of necessary connexion to be completely necessary connexion to be completely exhausted by the two factors of constant exhausted by the two factors of constant conjunction and customary inferenceconjunction and customary inference..

These two factors can be shown to apply in These two factors can be shown to apply in the moral realm, and he insists that we can’t the moral realm, and he insists that we can’t even even ascribeascribe any further necessity to matter: any further necessity to matter:

105105

““the ... advocates for [libertarian] free-will the ... advocates for [libertarian] free-will must allow this union and inference with must allow this union and inference with regard to human actions. They will only regard to human actions. They will only deny, that this makes the whole of necessity. deny, that this makes the whole of necessity. But then they must shew, that we have an But then they must shew, that we have an idea of something else in the actions of idea of something else in the actions of matter; which, according to the foregoing matter; which, according to the foregoing reasoning, is impossible.” (reasoning, is impossible.” (AA 34, cf.  34, cf. TT 2.3.1.3-18, 2.3.1.3-18, TT 2.3.2.4, 2.3.2.4, EE 8.4-22, 8.4-22, EE 8.27) 8.27)

Here Hume is arguing against the Causal Here Hume is arguing against the Causal Realist, who thinks that “we have an idea of Realist, who thinks that “we have an idea of something else in the actions of matter”.something else in the actions of matter”.

106106

““A New Definition of Necessity”A New Definition of Necessity”

Even more explicitly than with “Of the Even more explicitly than with “Of the Immateriality of the Soul”, Hume portrays his Immateriality of the Soul”, Hume portrays his argument here as turning on his new argument here as turning on his new understanding of necessity:understanding of necessity:

““Our author pretends, that this reasoning puts the Our author pretends, that this reasoning puts the whole controversy in a new light, by giving a new whole controversy in a new light, by giving a new definition of necessity.” (definition of necessity.” (AA 34) 34)

This requires that his definitions are This requires that his definitions are understood as specifying “the very essence understood as specifying “the very essence of necessity” (of necessity” (TT 2.3.1.10, 2.3.2.2). 2.3.1.10, 2.3.2.2).

107107

Anti-Realism supporting realismAnti-Realism supporting realism

all objects, which are found to be constantly all objects, which are found to be constantly conjoin’d, are conjoin’d, are upon that account onlyupon that account only to be to be regarded as causes and effects. … the regarded as causes and effects. … the constant conjunction of objects constitutes constant conjunction of objects constitutes the the very essencevery essence of cause and effect … of cause and effect …

( (TT 1.4.5.32, my emphasis) 1.4.5.32, my emphasis)

two particulars [are] essential to necessity, two particulars [are] essential to necessity, viz.viz. the constant the constant unionunion and the and the inferenceinference of the mind of the mind … wherever we discover these we must … wherever we discover these we must acknowledge a necessity. (acknowledge a necessity. (TT 2.3.1.4) 2.3.1.4)

108108

Reconstructing Hume’s VisionReconstructing Hume’s Vision

The “chief argument” of the The “chief argument” of the TreatiseTreatise (as (as summarised in the summarised in the AbstractAbstract of 1740) is of 1740) is almost entirely devoted to causation etc. – almost entirely devoted to causation etc. – TreatiseTreatise 1.3 is the central part of the work. 1.3 is the central part of the work.

Applying the Copy Principle to the idea of Applying the Copy Principle to the idea of necessary connexion reveals the nature of necessary connexion reveals the nature of causal necessity, settling fundamental issues causal necessity, settling fundamental issues about causation in the moral sphere, and about causation in the moral sphere, and eliminating aprioristic causal metaphysics.eliminating aprioristic causal metaphysics.

109109

The Cosmological ArgumentThe Cosmological Argument

Hume told Boswell that he “never had Hume told Boswell that he “never had entertained any belief in Religion since he entertained any belief in Religion since he began to read Locke and Clarke”began to read Locke and Clarke”

Both Locke and Clarke advocated the Both Locke and Clarke advocated the Cosmological ArgumentCosmological Argument, and insisted that , and insisted that matter cannot give rise to thoughtmatter cannot give rise to thought..

TreatiseTreatise 1.3.3 – which disputes the basis 1.3.3 – which disputes the basis of the Causal Maxim – identifies both of the Causal Maxim – identifies both Locke and Clarke by name (in footnotes).Locke and Clarke by name (in footnotes).

110110

The Origin of IdeasThe Origin of Ideas

Locke’s empiricism naturally raises the issue Locke’s empiricism naturally raises the issue of the origin of the idea of causal necessity, of the origin of the idea of causal necessity, central to the Cosmological Argument.central to the Cosmological Argument.

Locke’s “Of Power” (Locke’s “Of Power” (EssayEssay II xxi) gives an II xxi) gives an inadequate account: Hume sees this, and inadequate account: Hume sees this, and attempts to remedy the omission.attempts to remedy the omission.

Locke’s chapter focuses also on Free Will. Locke’s chapter focuses also on Free Will. Hume sees his account as supporting Collins Hume sees his account as supporting Collins against Clarke (a debate very familiar to him against Clarke (a debate very familiar to him through Dudgeon, Baxter, Desmaizeaux).through Dudgeon, Baxter, Desmaizeaux).

111111

An Integrated VisionAn Integrated Vision

Hume’s causal anti-Realism Hume’s causal anti-Realism refutesrefutes::– The Cosmological Argument;The Cosmological Argument;

– Anti-materialist arguments;Anti-materialist arguments;

– The Free Will Theodicy (cf. Hume’s early The Free Will Theodicy (cf. Hume’s early memoranda, from the late 1730s);memoranda, from the late 1730s);

– Aprioristic causal metaphysics in general.Aprioristic causal metaphysics in general.

At the same time it At the same time it supportssupports::– Empirical, causal science: the Empirical, causal science: the onlyonly way to way to

establish anything about “matters of fact”;establish anything about “matters of fact”;

– Extension of causal science into moral realm.Extension of causal science into moral realm.

4(g)4(g)

Hume, Hume, Determinism, Determinism, and Libertyand Liberty

Hume’s DeterminismHume’s Determinism

Hume is a determinist, in the sense that he Hume is a determinist, in the sense that he thinks everything happens in conformity thinks everything happens in conformity with universal, exceptionless causal laws.with universal, exceptionless causal laws.

Note that this is entirely compatible with:Note that this is entirely compatible with:– Hume’s view that the uniformity of nature Hume’s view that the uniformity of nature

cannot be cannot be provedproved..– Hume’s analysis of causal necessity.Hume’s analysis of causal necessity.

However the basis for his determinism is However the basis for his determinism is not entirely clear.not entirely clear.

113113

114114

Evidence for Hume’s DeterminismEvidence for Hume’s Determinism

We have seen that Hume’s letters evince a We have seen that Hume’s letters evince a commitment to the Causal Maxim:commitment to the Causal Maxim:

““Whatever begins to exist, must have a cause Whatever begins to exist, must have a cause of existenceof existence” (” (TT 1.3.3.1). 1.3.3.1).

In his sections “Of Liberty and Necessity”In his sections “Of Liberty and Necessity”((TT 2.3.1-2 and 2.3.1-2 and EE 8), Hume argues for the 8), Hume argues for the Doctrine of Necessity (Doctrine of Necessity (TT 2.3.2.3, 2.3.2.3, EE 8.3). 8.3).– It seems fairly clear from how he describes it It seems fairly clear from how he describes it

that Hume takes this “doctrine” to be the thesis that Hume takes this “doctrine” to be the thesis of determinism …of determinism …

Hume’s Statement of NecessityHume’s Statement of Necessity

“’“’Tis universally acknowledg’d, that Tis universally acknowledg’d, that the the operations of external bodies are necessaryoperations of external bodies are necessary, , and that in the communication of their motion, and that in the communication of their motion, in their attraction, and mutual cohesion, in their attraction, and mutual cohesion, there there are not the least traces of indifference or libertyare not the least traces of indifference or liberty. . Every object is determin’d by an absolute fate Every object is determin’d by an absolute fate to a certain degree and direction of its motion, to a certain degree and direction of its motion, and can no more depart from that precise line, and can no more depart from that precise line, in which it moves, than it can convert itself into in which it moves, than it can convert itself into an angel …an angel …

115115

116116

… … The actions, therefore, of matter are to be The actions, therefore, of matter are to be regarded as instances of necessary actions; and regarded as instances of necessary actions; and whatever is in this respect on the same footing whatever is in this respect on the same footing with matter, must be acknowledg’d to be with matter, must be acknowledg’d to be necessary. necessary. That we may know whether this be That we may know whether this be the case with the actions of the mindthe case with the actions of the mind, we shall , we shall begin with examining matter, and considering on begin with examining matter, and considering on what the idea of a necessity in its operations are what the idea of a necessity in its operations are founded …” (founded …” (TT 2.3.1.3) 2.3.1.3)

Hume then goes on to appeal to his two Hume then goes on to appeal to his two definitions, as we saw earlier.definitions, as we saw earlier.

The Necessity of Human BehaviourThe Necessity of Human Behaviour

117117

The Doctrine of Liberty: A Contrast The Doctrine of Liberty: A Contrast between between Treatise Treatise and and EnquiryEnquiry

In the In the EnquiryEnquiry, Hume famously pursues ‘a , Hume famously pursues ‘a reconciling project’ (reconciling project’ (EE 8.23), presenting a  8.23), presenting a compatibilistcompatibilist solution to the problem of free solution to the problem of free will and determinism.will and determinism.

Following Hobbes, he sees Following Hobbes, he sees the doctrine of the doctrine of necessitynecessity as entirely compatible with as entirely compatible with the the doctrine of libertydoctrine of liberty – i.e. the claim that some – i.e. the claim that some of our actions are of our actions are freefree..

But in the But in the TreatiseTreatise, Hume understands , Hume understands “liberty” as “liberty” as chancechance., which he denies.., which he denies.

118118

“… “… this fantastical system of liberty …” this fantastical system of liberty …” ((TT 2.3.1.15) 2.3.1.15)““According to my definitions … liberty … is According to my definitions … liberty … is the very same thing with chance. As the very same thing with chance. As chance is commonly thought to imply a chance is commonly thought to imply a contradiction, contradiction, and is at least directly and is at least directly contrary to experiencecontrary to experience, there are always , there are always the same arguments against liberty or the same arguments against liberty or free-will.” (free-will.” (TT 2.3.1.18) 2.3.1.18)“… “… the doctrine of liberty, however absurd the doctrine of liberty, however absurd it may be in one sense, and unintelligible it may be in one sense, and unintelligible in any other.” (in any other.” (TT 2.3.2.1) 2.3.2.1)

The Evidence for DeterminismThe Evidence for Determinism

““philosophers … find, that it is at least philosophers … find, that it is at least possible the contrariety of events may not possible the contrariety of events may not proceed from any contingency in the cause, proceed from any contingency in the cause, but from the secret operation of contrary but from the secret operation of contrary causes. causes. This possibility is converted into This possibility is converted into certaintycertainty by farther observation; when they by farther observation; when they remark, that, upon an exact scrutiny, a remark, that, upon an exact scrutiny, a contrariety of effects always betrays a contrariety of effects always betrays a contrariety of causes, and proceeds from contrariety of causes, and proceeds from their mutual opposition.” (their mutual opposition.” (TT 1.3.12.5;  1.3.12.5; EE 8.13) 8.13)

119119

120120

Determinism and MoralityDeterminism and Morality

It is commonly assumed that determinism would It is commonly assumed that determinism would undermine moral responsibility, but Hume undermine moral responsibility, but Hume argues that on the contrary, argues that on the contrary,

““this kind of necessity is so essential to religion and this kind of necessity is so essential to religion and morality, that without it there must ensue an absolute morality, that without it there must ensue an absolute subversion of both … as all human laws are founded subversion of both … as all human laws are founded on rewards and punishments, ’tis suppos’d as a on rewards and punishments, ’tis suppos’d as a fundamental principle, that these motives have an fundamental principle, that these motives have an influence on the mind, and both produce the good and influence on the mind, and both produce the good and prevent the evil actions. … common sense requires it prevent the evil actions. … common sense requires it shou’d be esteem’d a cause, and be look’d upon as shou’d be esteem’d a cause, and be look’d upon as an instance of that necessity” (an instance of that necessity” (TT 2.3.2.5) 2.3.2.5)