3IO BOOK REVIEWS his essay in this volume 'Determinism and the Study of Man'. I find it difficult to see how he has done this and what, if anything, remains of his claim in the original book that 'the practical syllogism provides the sciences of man with an explanation model in its own right'. The collection contains some interesting material, but in the end what it seems to show is that Von Wright's 'Explanation and Understanding' Downloaded from https://academic.oup.com/mind/article/LXXXVII/2/310/956669 by guest on 29 September 2021 does not deserve the attention this symposium gives it.

UNIVERSITY OF BRISTOL D. E. MILLIGAN

Perception, Common Sense and Science. By JAMES W. CORNMAN. Yale University Press, 1975. Pp. 420. £11. This large volume is tightly packed with carefully worded statements and carefully tabulated arguments. It contains acutely argued distinctions and conclusions which help the mind, and not only in the analytical taxonomy of philosophical positions. It covers many talking-points in and around the philosophy of perception, reaching into the philosophy of science. While we need not expect philosophers to agree as to what are the most important objections to a given contention, all or most of the objections Cornman mentions are well worth mentioning. Through a difference of approach, however, I find myself alienated from many of Cornman's characterisations and categorisations. Re- currently I find that 'I would not have called that a such-and-such'—a belief, a fact, a theory, metaphysical, a premiss, common sense, a problem, a solution, evidence, probable, reasonable. In that respect, for a reader who has been influenced by Wittgenstein, Wisdom, Ayer, Ryle or Austin, it is like reading Broad or Ewing. In other respects, not; there is certainly no lack of up-to-date analytical concepts. Wisely or not, but understandably at any rate, Cornman is not content merely to withhold his assent from what he recognises to be the unclear traditional doctrine that we never 'directly perceive' physical things. He tries to define a sense of 'directly perceive' in which the opposing state- ment, that we do sometimes 'directly perceive' physical things, can be defended—not as evident fact but as a reasonable philosophical theory. To define the terms of that statement in such a way that it expresses an evident fact is easy; just make it mean that we sometimes perceive physical things by looking directly at them. To define the terms of a statement in such a way that it turns out to be a reasonable philosophical theory is in contrast either difficult or impossible, and indeed Cornman's book will not lead any reader to underestimate the difficulties and the particular controversialities that such an enterprise involves. If Comman neverthe- less thinks his task worth while, this reflects his declared purpose of making, in the totality of his writings, an interconnected set of statements about man and nature that are philosophical or even metaphysical but that aim at exactitude. Yet someone could have that un-Wittgensteinian objective without wanting to piece together so many of the fragments of traditional Anglo-Saxon epistemology. BOOK REVIEWS 311 The thesis Cornman defends is, in his own outline formulation, that 'we directly perceive sensuously-coloured physical objects, which are made up of the unobservable particulars posited by Science'. Cornman also asserts, in the course of a long and contextually important Intro- duction, that many or even most of us, when we are not theorising, behave and talk as if we believe that we directly perceive various physical Downloaded from https://academic.oup.com/mind/article/LXXXVII/2/310/956669 by guest on 29 September 2021 things. I am not sure whether he means that we behave and talk as if we believe that we 'directly perceive' those things in the complex sense which he carefully defines. I have not been able to convince myself that we do. Or even quite to see how we would have to behave and talk when not theorising, in order to be deemed to have behaved and talked as if we believed that, exactly. Nor do I see an alternative way of interpreting Cornman's claim about our everyday behaviour, in which it comes out true. I see no very close connection between Cornman's direct- perception thesis and our everyday beliefs. However, this does not settle the question whether Cornman's direct-perception thesis is one that we have a right to accept. In defending his thesis, Cornman is using the notion of a 'sensum*. For although he is by no means saying that there are sensa, he is not just withholding assent from the doctrines in which sensa are posited. His definition of direct perception is such that, in saying of a subject S that he directly perceives something, y, you are saying two things. You are saying that S perceives y. And you are saying that there is no sensum or group of sensa x, non-identical with y and neither a constituent of y nor having y as a constituent, such that S's perceptual experience of y consists in his experiencing x. The notion of a sensum is deliberately used by Cornman in a way which he recognises to be unusually broad. A sensum is a phenomenal individual, that is, an individual that exists when and only when experienced and that has at least one phenomenal property— roughly, a non-physical property something has when, and only when, it is experienced to have that property. The term, 'an individual', is left undefined, but a contrast with events is evidently intended. Otherwise, sensings and perceivings might by some thinkers be claimed to be phenomenal individuals. Cornman's strategy is to step, by means of three principles of reason, from there being no good reason for positing sensa to there being good reason to deny them. His possibly insecure, and to me doubly unattrac- tive, categorisation of his own direct-perception thesis as a metaphysical theory has relevance here. For the three principles are very much about Theory. Moreover one can confidently predict that the principles will be found controversial and/or ambiguous in themselves as well as in their application. I am not convinced that, from there being no good reason to posit entities of kind K, it even follows—as Comman claims— that it is more reasonable to deny than to posit them. The principle of giving some preference to the pre-theoretical beliefs of mankind is supposed to favour realism; it will not work in that way for those of us who fail to see how you can reasonably posit a consensus when you are not yet positing external objects. There is appropriately more to Cornman's Realism than appears in 312 BOOK REVIEW8 the authorised outline formulation I have quoted. Notably it involves a rejection of a phenomenalism of 'sensings'. Startlingly, acceptance of the Realism is claimed to make it unreasonable to accept any form of materialism. As one might infer, 'materialism' is narrowly redefined.

Several of the many things in the book that I have no space to mention Downloaded from https://academic.oup.com/mind/article/LXXXVII/2/310/956669 by guest on 29 September 2021 can be highly valued in and by themselves. WORCESTER COLLEGE, OXFORD J. M. HINTON

Teleology. By ANDREW WOODFIELD. Cambridge University Press, 1976. Pp. viii+232. £6.50. There are a number of important questions that fall under the general rubric teleology, the title of Andrew Woodfield's interesting book. Might there be, now or in the future, man-made devices capable of purposeful behaviour? Can behaviourist psychology account for the purposeful behaviour shown by human beings? Is functional analysis an appropriate programme for sociology? If we take as our starting point behaviour that is informed by an agent's consciously entertained purpose we may identify one influential approach in recent years as attempting to represent such consciously purposive behaviour as a special case of a wider phenomenon—as a sub-class of behaviour that is 'goal-directed'; and as maintaining that we draw the boundaries round this wider category by reference to a distinctive pattern displayed by all the behaviour that is to fall within them. Approaches of this type, and related ones, Woodfield labels 'behaviourist', and for good reason. Most obviously, subsuming con- sciously purposive behaviour under the wider category of behaviour that is goal-directed suggests that the role of conscious experience is not a decisive one; but the behaviourist will also be attracted by an interpretation which suggests that the identifying feature of a piece of behaviour is the pattern that it falls under, instead of the nature of the state out of which it emerged. After conducting sustained critiques of what he takes to be the major variants of the 'behaviourist' interpretation— those of Braithwaite, Sommerhoff and Charles Taylor—Woodfield's conclusion is that the general approach is flawed in two basic ways. None of the variants can offer any plausible account of the fact that some systems which display goal-directed behaviour can change the goal they are pursuing from one moment to the next, nor can they account plausibly for the fact that a system may have a goal at a particular time, and yet not act on it. Woodfield's own approach, not without precedent, is to insist that to solve these problems the first thing is to get clear about the meanings of the terms involved. He accepts a little reluctantly that the term 'goal- directed' does indeed mark a non-arbitrary category of behaviour, but he argues that it is defined not by a common pattern of behaviour but by reference to an independently defined category of behaviour and by