The Revolutionary.. ‘If’ Victor Howard Dudman

Preview:

Citation preview

The Revolutionary .. ‘If’

Victor Howard Dudman

Mark Thakkar

Amyas Merivale

…and somebody else

The Principles of Ingsoc

War is PeaceFreedom is Slavery

Ignorance is Strength

The Principles of Oxlog

Sentence determines message

Truth is a property of sentences

‘’If’ is ‘’

[A] If Oswald didn’t shoot Kennedy, somebody else did

whines, we beat him[B] If Oswald doesn’t shoot Kennedy, somebody else

will

[C] If Oswald hadn’t shot Kennedy, somebody else

would have

If James whines, we beat him whines, we beat him

If James whines, we beat him whines, we beat him

If James whines, we beat him whines, we beat him

If James whines, we beat him whines, we beat him

Hypothetical message

(Logical)

If James whines, we beat him whines, we beat him

Habitual message

If James whines, we beat him whines, we beat him

Fantasy message

If the door was locked, Grannie jumped in through the window

Hypothetical message

(Logical)

If the door was locked, Grannie jumped in though the window

whines, we beat him

Habitual message

If she misses the last bus, Her Majesty will walk home

Fantasy message

If she misses the last bus, Her Majesty will walk home

Habitual message

Stand Alone

If P, then Q

There is an antecedent

If Oswald didn’t shoot Kennedy, somebody else did

whines, we beat him.Oswald didn’t shoot

Kennedy.(YES)

If Her Majesty misses the last bus, she will usually walk

home

.Her Majesty misses the last bus.

(NO)

If the vicar annoys Grannie again, she will show no mercy

.The vicar annoys Grannie again.

(NO)

Contraposition

If P, then Q

If not Q, then not P

If Oswald didn’t shoot Kennedy, somebody else did whines, we

beat himIf nobody else shot

Kennedy, then Oswald did(YES)

If Her Majesty misses the last bus, she will usually walk home

If Her Majesty will not usually walk home, she

doesn’t miss the last bus.(NO)

If the vicar annoys Grannie again, she will show no mercy

If Grannie will show mercy, the vicar doesn’t annoy Grannie again.

(NO)

Time and Tense

Tense: time registered by formTime: time the message is

about

If Oswald didn’t shoot Kennedy, somebody else did whines, we

beat himTense: PastTime: Past

(Tense = Time)

If Her Majesty misses the last bus, she will usually walk home

whines, we beat himTense: PresentTime: Present

(Tense = Time)

If the vicar annoys Grannie again, she will show no mercy

Tense: PresentTime: Future

(Tense < Time)

If Grannie commits suicide, she will make it look like murder

Tense: Present

Time about: Future

If Grannie commited suicide, she would make it look like murder

Tense: Past

Time about: Future

If the accountants had come tomorrow, they would have found

our books in order

Tense: Past past

Time about: Future

If Oswald doesn’t shoot Kennedy, somebody else will

Tense: Present

Time about: Future

If Oswald hadn’t shot Kennedy, somebody else would have.

Tense: Past Past

Time about: Past

Logical messages

• Pass Stand-Alone

• Contrapose

• Tense = Time

Habitual messages

• Fail Stand-Alone

• Don’t contrapose

• Tense = Time

Fantasy messages

• Fail Stand-Alone

• Don’t contrapose

• Tense < Time

Non-logical hypothetical messages

• The dog – if it was a dog – ran off

• If it rained, it didn’t rain hard• If the Mayor is married, his

wife did not accompany him

Non-logical hypothetical messages

• If it didn’t run off, it wasn’t a dog

• If it rained hard, it didn’t rain• If his wife did accompany him,

the Mayor is not married

Non-logical hypothetical messages

• Pass Stand-Alone

• Don’t Contrapose

• Tense = Time

[A] If Oswald didn’t shoot Kennedy, somebody else did

whines, we beat him[B] If Oswald doesn’t shoot Kennedy, somebody else

will

[C] If Oswald hadn’t shot Kennedy, somebody else

would have

Logical messages …

… are condensed arguments

If P, then Q

P. So Q

If Oswald didn’t shoot Kennedy

…then somebody else did

Oswald didn’t shoot Kennedy

So: Somebody else did

Logical messages

• Cannot have truth-values

• Their standard is deductive validity

Habitual messages

• Do have truth-values

• They are propositions

• - claims of fact about their tenses.

Fantasy messages

• Cannot have truth-values

• Are not propositions

• Are justified by inductive reasoning

The Bad News

• Almost every prelim examination over the last few years has misunderstood all this.

The Good News

• Your tutors can cope

20 September

480 B.C.

The Battle of Salamis

DATELINE 19 SEPTEMBER

THE EVE OF THE BATTLE

Artful Themistocles

DATELINE 20 SEPTEMBER

THE DAY OF THE BATTLE

Brave Aristides

DATELINE 21 SEPTEMBER

THE DAY AFTER THE BATTLE

Herodotus

Father of Greek History

Aeschylus

Father of Greek Tragedy

?

What the fuck?

I mean, er.. what the

fucking fuck?

We are young men and women of high spirit and noble ideals.

We are philosophers, interested in the semantics of English ‘if’.

What in God’s name are we doing here?

Aristotle

De Interpretatione

De Interpretatione 9"With regard to what is and

what has been it is necessary for the affirmation or the negation to be true or false ................ .....But with particulars that are going to be it is different."

DATELINE 19 SEPTEMBER

THE EVE OF THE BATTLE

[19A]    There will be a sea-

battle tomorrow

[19B]    There will be a sea-

battle tomorrow

even if a storm destroys the Persian

fleet overnight

DATELINE 20 SEPTEMBER

THE DAY OF THE BATTLE

[20A]   There is a sea-battle

going on now

[20B]    There is a sea-battle

going on now

even if a storm destroyed the Persian

fleet overnight

DATELINE 21 SEPTEMBER

THE DAY AFTER THE BATTLE

[21A]   There was a sea-battle yesterday

[21B]    There was a sea-battle yesterday

even if a storm destroyed the Persian fleet the night before

[1] LOGIC

• PAST: There was a battle yesterday

• PRESENT: There is a battle (raging) now

• FUTURE: There will be a battle tomorrow

[2] TRUTH-VALUE

• PAST: There was a battle yesterday

• PRESENT: There is a battle (raging) now

• FUTURE: There will be a battle tomorrow

[3] NEGATION

• PAST: There was a battle yesterday• There was no battle yesterday

• PRESENT: There is a battle (raging) now• There is no battle (raging) now

• FUTURE: There will be a battle tomorrow• There might be no battle tomorrow

‘Will’ and ‘Will not’ are not contradictories

They are contraries

Messages about the Future

• Are Fantasy messages

• Cannot have truth-values

• Are not propositions – claims of fact about their tenses

• They are ……

Judgements

Fin