A Pragmatic Theory of Scientific Explanation

1. A PragmaticTheory of ScientificExplanation RaoulGervais

2. BasicIdea • Construct a theory of scientificexplanation ‘bottom up’; i.e. bystartingfromananalysis of scientificpractice • Considerexamplesfrom a wide range of disciplines

3. BasicIdea • Explanations as answers to why-questions • Why-questionsoriginate in different epistemicinterests • Epistemicinterestsinfluence the structure of explanations • Epistemicinterests provide a context in which to analyzeexplanatory power

4. Specificquestions • Whichepistemicinterestscanlead to explanationrequests and how do theyrelate to eachother? • What does thistellusabout the possiblestructures of scientificexplanations? • What does thistellusabout the criteria forassessingexplanatory power?

5. Goals • To answer these questionssystematicallyfor a wide range of disciplines • Seewhat these answers have in common • Arrive at a scientificallyinformedtheory of explanation

6. My contribution • To answer these questionsfor: • Psychology • Biology • Relating these answers back to the overall project • Example of current research

7. Explainingdepression • What kind of epistemicinterestsmightone have concerningdepression? • Basicunderstanding • Description • Prediction • Prevention • Therapeutic interest

8. Explaining depression • Look at neuroticism: like depression, a psychologically defined state: irritability, anger, anxiety etc. • Is statistically identified as cause of depression: depression explained as an effect of neuroticism, which is fine if our epistemic interest is prediction or description

9. Explainingdepression • Preventive/therapeutic • Psychotherapy • Neurology

10. The problem of interlevelexplanation • Withinthisparticular account, interlevelexplanation poses a particularproblem: • So then, if neuroscientific explanations are going to compete with psychological ones with respect to a set of questions, the contrast class for the two domains questions [sic] would have to correspond. But because psychology and neuroscience operate in such different academic environments, prima facie it is doubtful that the contrast classes do correspond. At least, we would need an argument that the contrast classes are importantly similar (Hardcastle 1998, p. 16-17).

11. The erotetic account • Obvious solution: translating vocabularies • However, the example of classical reductionism acts as a deterrent • Proposal: • Pragmatic factors suggest on what level to look • First, hypothetical interlevel identities are assumed • Next, the identity is confirmed by experiments/manipulation • So, the second and third requirments are met: pluralism regarding levels, but what level is chosen is determined by pragmatic factors

12. The depression/neuroticism example • The pragmatic factors suggest where to look: in the case of neuroticism, over six decades of experimentation has established link to serotonin levels • At first, this was a mere hypothesis (Wooley and Shaw) • But has since been confirmed by experimentation and a successful track record (pharmacology)

13. The depression/neuroticismexample • A quote fromWoolley & Shawsaysit in a nutshell: • …these pharmacological findings indicate that serotonin has an important role to play in mental processes and that the suppression of its action results in a mental disorder. If now a deficiency of serotonin in the central nervous system were to result from metabolic rather than from pharmacologically induced disturbances, these same mental aberrations would be expected to become manifest. […] If the hypothesis about serotonin deficiency is accepted, then the obvious thing to do is to treat patients having appropriate mental disorders with serotonin (Woolley & Shaw 1954 p. 230).