Explanatory mechanisms: The contribution of systems thinking and critical realism

Professor John MingersKent Business School (j.mingers@kent.ac.uk)

University of KentNovember 2011

Philosophy of Science

Critical Realism

Systems and Cybernetics

Mechanisms

1. Introduction: The Philosophy of Science

Explanatory mechanisms

• Philosophy of science: the nomological tradition• Hempel’s deductive-nomological model (D-N)• Induction and falsificationism

• The alternative: mechanistic explanation• Particular mechanisms are hypothesised that would

generate the phenomena of interest• Avoids problems with D-N and fits better with what

scientists actually do

Bechtel, W. and A. Abrahamsen (2005). 'Explanation: A mechanist alternative', Studies in History and Philosophy of Biological and Biomedical Sciences, 36, pp. 421-441.

Chakravartty, A. (2005). 'Causal realism: Events and processes', Erkenntnis, 63.Craver, C. (2006). 'When mechanistic models explain', Synthese, 153, pp. 355-376.Craver, C. (2007). Explaining the Brain, Clarendon Press, Oxford.Darden, L. (2006). Reasoning in Biological Discoveries, Cambridge University Press, Cambridge.Gerring, J. (2007). 'Review article: The mechanismic worldview: Thinking inside the box', British Journal of Political

Science, 38, pp. 161-179.Glennan, S. (1996). 'Mechanisms and the nature of causation', Erkenntnis, 44, pp. 49-71.Glennan, S. (2002). 'Rethinking Mechanistic Explanation', Philosophy of Science, 69, pp. S342-S353.Illari, P. and J. Williamson (2011). 'Mechanisms are real and local'. In: P. Illari and J. Williamson (eds.), Causality in the

Sciences. pp. 818-844. Oxford University Press, Oxford.Machamer, P. (2004). 'Activities and causation: The metaphysics and epistemology of mechanisms', International Studies

in the Philosophy of Science, 18, pp. 27-39.Machamer, P., L. Darden and C. F. Craver (2000). 'Thinking about Mechanisms', Philosophy of Science, 67, pp. 1-25.Salmon, W. (1998). Causality and Explanation, Oxford University Press, Oxford.Salmon, W. (1998). 'Comets, pollen and dreams: Some reflections on scientific explanation'. Causality and Explanation.

pp. 50-67. Oxford University Press, Oxford.Torres, P. (2009). 'A modified conception of mechanisms', Erkenntnis, 71, pp. 233-251.Wimsatt, W. (2007). Re-Engineering Philosophy for Limited Beings: Piecewise Approximations to Reality, Harvard

University Press.

The literature makes little reference to systems thinking (e.g., Maturana) or critical realism (Bhaskar)

2. The logic of mechanistic explanation: not deduction or induction but abduction

• Deduction: Given a general law or rule, we can deduce that particular instances will follow from it• But, where does the law come from?

• Induction: Given empirical instances, we can induce a general law to cover them• But, see the Hume/Popper critiques of induction

• Abduction (also called retroduction): Given some phenomena to explain, what mechanism might have generated it?“Abduction consists in studying facts and devising a theory to explain them” (Peirce,

1903, “5th Lecture on Pragmatism”)

• Critical realism (Bhaskar): generative mechanisms• The Real consists of stratified causal mechanisms that interact with each

other• The Actual are the events and occurrences generated by the real

mechanisms• The Empirical are those events in the actual that are observed for

scientific purposes • Methodology (DREI)

• Describe an unusual phenomena or anomaly• Retroduct putative causal mechanisms which, if they existed, would

generate the phenomenon• Eliminate alternative explanations• Identify the correct mechanism

Explanatory mechanisms

The REAL: mechanisms and structures with enduring properties

The ACTUAL: events (and non-events) that are generated by the mechanisms

The EMPIRICAL: events that are actually observed and experienced

3. Systems thinking and autopoiesis• In essence, a mechanism is the same as a system. It is

characterised in terms of:• Parts/wholes, boundaries, emergence, hierarchy, information and

feedback (cybernetics) and the observer (2nd order cybernetics, soft systems thinking)

• Maturana’s mechanistic philosophy – close to critical realism• Presentation of the experience (phenomena) to be explained so that a

standard observer can experience it• Reformulation into a generative mechanism that if realised would allow

the observer to experience it• Deduction of other experiences that should follow from the mechanism• Occurrence of these experiences

(Maturana, 1990, “Science and Daily Life”)

4. Issues in mechanistic explanationA. The nature of mechanistic explanation

• D-N model is reductionist, reducing the real to the actual and the actual to the empirical. CR and systems is emergent and holistic

• There is a distinction between epistic and ontic explanations. Is it the explanation (model or theory) that does the explaining or the mechanism itself? This is a difference between CR (both transitive and intransitive domains of science) and Maturana (constituted objectivity not transcendental objectivity)

B. The reality of mechanisms• Two arguments against the reality of mechanisms

• Positivism – unobservable theoretical entities• Maturana – cannot escape the world of experience and observation

• Bhaskar’s transcendental arguments for realityPremise 1: There is some X that we experience or agree aboutPremise 2: X could not be experienced if Y were not the caseConclusion: Y must be the case

• Are unobservable social mechanisms real?• Bhaskar’s transcendental arguments apply although with

modifications to the nature of social systems• Is mechanistic explanation inevitably functionalist?

• Not according to Maturana and Giddens

C. Must mechanisms be local?• Most philosophers argue that mechanisms must “local” in a

physico-temporal sense. But there are questions:• How does one draw the boundaries?• Especially for non-physical systems?• Omissions or absences as causes?

• Systems can be defined differently over similar sets of components

• Systems involve both physical and non-physical elements (e.g., information)

• Social systems are not physically embodied, e.g., “the market”

D. Absences and omissions as causes• Philosophy of science in general, and empiricism in particular, emphasis

the positive – what actually happens (actualism)• But things that do not happen (when expected) are also causes:

• Simple or ontological absence (de-ont), e.g., an unpaid bill• Absenting or negating something, e.g., draining unwanted water or

absenting an absence, e.g., removing a need or want• A process that produces an absence, e.g., shopping producing lack

of money• A product that produces an absence, e.g., lack of money produces

lack of education• This also occurs in cybernetics, e.g., feedback loops trying to close a

gap, or mechanisms selecting from many absent possibilities (Luhmann)

“Causal explanation is usually positive. ... In contrast to this, cybernetic explanation is always negative. We consider what alternative possibilities could conceivably have occurred and then ask why were many of the alternatives not followed, so that the particular event was one of those few which could, in fact, occur.” (Bateson 1973, p. 375)

5. Conclusions• Systems thinking, philosophy of science and critical realism are all using

mechanism as an explanatory construct, but are not speaking to each other• Distinguish between the events that occur (and do not occur) - the actual and the

underlying, enduring structures and mechanisms, the real, that, through the operation of their powers in interaction, causally generate these events.

• Distinguish between the transitive domain of science (which is epistemic) in which theories and knowledge is humanly produced, and the intransitive domain of the independent objects of our knowledge (which is ontic).

• We can accept the reality of mechanisms (or systems more generally) may be non-physical and/or non-observable. The ontological criterion should not be perceptability but causal efficaciousness.

• Mechanistic explanation does not have to be a form of functionalist explanation.• Mechanisms do not have to be localised in a purely physical sense although they

need to be bounded, or able to be demarcated, within their space of interactions.• Absences and omissions may be causes and thus may legitimately be part of

mechanistic explanations.