Division of Humanities and Social Sciences, 228-77, California Institute of Technology, Pasadena, CA 91125, USA
Dr Turner is quite wrong to argue that Donald Davidson has shown there cannot, in any useful sense, be a science of the mental because of the impossibility of either strict psychological or strict psychophysical laws (Turner, 2003: p. 472). It is true that Davidson (1970) argued that there could not be strict laws relating mental events either to physical events or to each other, but its lack of strict laws does not endanger the scientific status of psychiatry, since strict laws are rare in science.
Davidson argues that the relationship between a cause and an effect is strictly lawful if and only if the cause is always followed by the effect irrespective of what else is going on; a sentence stating that the cause occurred must logically entail a sentence asserting the existence of the effect. Davidson (1993: pp. 89) concedes that this very demanding conception of a law is something that one could at best hope to find in a developed physics and that there are not, and perhaps could not be expected to be, laws of this sort in the special sciences. Most, if not all, of the practical knowledge that we (or engineers, chemists, geneticists and geologists) have that allows us to predict and explain ordinary happenings does not involve strict laws.
In the special sciences (by which philosophers mean all the sciences except physics) laws hold only under normal circumstances; unlike strict laws, they may fail to hold if circumstances are sufficiently abnormal. Davidson's view is quite consistent with the existence of laws in psychiatry that are not strict but are as robust and useful as laws in genetics, chemistry or geology. Unless one thinks that chemistry, genetics and geology are useless, this means that there could be laws robust enough to make psychiatry a useful science of the mind. If psychiatry counts as a science in the same sense as genetics counts as a science, even the most fervent proponents of scientific psychiatry should be satisfied.
REFERENCES
Davidson, D. (1970) Mental events. Reprinted in Essays on Actions and Events, pp. 207 -227. Oxford: Clarendon Press.
Davidson, D. (1993) Thinking causes. In Mental Causation (eds J. Heil & A. Mele), pp. 3 -19. Oxford: Clarendon Press.
Turner, M. A. (2003) Psychiatry and the human
sciences. British Journal of Psychiatry,
182, 472
-474.
Duchess of Kent's Psychiatric Hospital, Horne Road, Catterick Garrison, North Hospital, Horne Road, Catterick Garrison, North Yorkshire DL9 4DF, UK
Author's reply: Concerning the substantive philosophical issues, while Drs Murphy and Owen and colleagues are correct that Davidson himself embraces non-strict laws, the important question has always been whether or not his anomalous monism, like any form of non-reductive materialism, is entitled to them. Essentially, as many of Davidson's commentators have pointed out, non-strict laws lead to intractable difficulties with mental causation (Kim, 1993). The upshot is that non-reductive materialism faces the horns of an interpretationistreductionist dilemma. My editorial makes it plain which horn I prefer to be impaled on and my discussion of Philosophical Anthropology (Turner, 2003) was an attempt to explain why interpretationism is not compatible with laws of any kind. The reason, which is worth reiterating, is that mental states qua interpretations are not, as Murphy and Owen et al assume, brute data. Understanding their meanings is a presupposition of formulating the very laws on which non-reductive materialism is allegedly based (Von Wright, 1971).
This brings me to Owen et al's puzzling claim that biological psychiatrists are not trying to solve the mindbody problem. One reason the claim is puzzling is that Owen et al's correlations are the very non-strict laws that, by their own admission, have played a crucial role in recent attempts to solve the mindbody problem. In any case, I think we can safely say that the mindbody problem, like Owen et al's argument, would be helped considerably by the discovery of non-strict laws. The authors, of course, realise this and proceed to inform us that their existence is obvious. I must say that if their existence were as obvious as Owen et al make out, then it is unlikely that they would have had to rely on Penfield to justify their claims. Indeed, it is interesting that while Owen et al are keen to remind us that Jaspers is not the last word in psychopathology, they are oblivious to the implications of allowing that Penfield is the last word on psychophysical correlations.
From the hermeneutical perspective what makes mental states mental states is that they are rationally and holistically related to one another. Once these relations are removed, as they are, for example, in hallucinations, autochthonous delusions and Penfieldesque states, then it becomes difficult to justify the claim that the phenomena in question are mental states. This is where Jaspers' notion of un-understandability comes in. Un-understandability is introduced by Jaspers precisely to signal that in some circumstances the search for understanding must be replaced by the search for psychophysical correlations. Therefore, one might reasonably have expected that even if cognitive psychologists labouring to extend the boundaries of folk-psychological understanding found Jaspers' notion obstructive to progress, Owen et al would embrace it. Instead, they apparently find Jaspers' contribution obscure, and to justify their claim they are content to appeal simply to the authority of Cutting.
Criticisms of criticisms aside, what does seem obvious is that the dividing line between psychopathology and normality can only be arbitrarily drawn. This suggests that Owen et al are really advocating, not extricating psychiatry from the humanities, but extricating humanity from the humanities. Ridiculous as this may seem, it should come as no surprise since it is what most biological psychiatrists secretly think is possible anyway.
REFERENCES
Kim, J. (1993) The non-reductivist's troubles with mental causation. In Mental Causation (eds J. Heil & A. Mele), pp. 189-210. Oxford: Clarendon Press.
Turner, M. A. (2003) Psychiatry and the human
sciences. British Journal of Psychiatry,
182, 472
-474.
Von Wright, G. H. (1971) Explanation and Understanding. London: Routledge and Keegan Paul.