1 In New Essays in the Philosophy of Mind, John, King-Farlow and Roger A., Shiner eds., Canadian journal of Philosophy Supplementary Volume No.1, Part 2 (1975), pp. 171–183.Google Scholar

2 Ibid., p. 174. Precisely this argument is considered by C.D., Broad (The Mind and its Place in Nature, London, 1925, pp. 119–120)Google Scholar, and attributed by him to William James. Broad claims that this argument is “quite obviously invalid” (119); his reasons for thinking this, however, are different from ours, and are, in our opinion, equally invalid. Broad says: “Natural selection is a purely negative process; it simply tends to eliminate individuals and species which have variations unfavourable to survival. … [I]t does not account for the origin or for the growth in complexity of anything whatever.” Broad is right about natural selection alone; but evolutionary theory also postulates random variation of characteristics; these two explain the origin and proliferation, as well as the disappearance of characteristics. We thank the Executive Editors of the Canadian journal of Philosophy for having pointed out this passage in Broad to us.

3 In fact, certain regularities, for example, laws of chemistry, physics, biology, etc. are needed in addition to the principles of evolution to explain and predict certain evolutionary changes; e.g., the fact that a bird has a certain form of wing rather than another can be explained by the principles of evolution in conjunction with certain principles of aerodynamics, which show why the having of the one wing shape allows flying with less expenditure of energy, compared to the other, and thus why the having of the first is a relative advantage. lf these laws are needed in addition to the principles of evolution to provide a complete explanation, they can hardly be explained by the principles of evolution.

4 From a standard biology text: Weisz, The Science of Biology, p. 769.

5 Indeed the theory specifically allows for the occurrence of such characteristics and the question of their ubiquity is one of pressing biological interest. We quote from a recent work, The Philosophy of Biology, by M. Ruse (London, 1973), p. 115:

[T]here are at least five reasons why evolutionists think some characters might not be adaptive …. One is the possible existence of genetic drift, leading to the fixation of non-adaptive (or even positively disadvantageous) characters. Another is pleiotropism. If a pleiotropic gene causes two phenotypic characters, one of which is adaptive and the other inadaptive, it might be to the organism's benefit to tolerate the latter for the sake of the former. A third reason is changed conditions. A character may once have been adaptive, but, with changed environmental conditions, is no longer so. As yet, it has not disappeared from the population. A fourth reason is a character having two roles. The peacock's tail may attract the peahen; but at the same time, it may make its owner vulnerable to attack. Fifthly, there is allometric growth. Some genes cause phenotypic characters to grow more rapidly than the rest of the body, and these characters continue growing after the sexual maturity is reached. They may give their owners the reproductive edge over other organisms, even though later they prove to be a handicap (by which time, the genetic damage is done).

6 Brandt, and Kim, “The Logic of the Identity Theory,” The journal of Philosophy, Vol. LXIV, No. 17, Sept. 7, 1967. Quoted by Puccetti on p. 175.Google Scholar

7 p. 176.

8 p. 176.

9 This is rather generous. The experimental findings do not seem to be unequivocal and Puccetti makes certain assumptions in the descriptions of the findings. Among these are the assumptions that the experiments in the first example show that the cortical processes are not accompanied by consciousness (and that it is not the case that there is consciousness but that the characteristic outward signs of it have been repressed); and that the experiments in the second example show the epileptic and sleepwalker are in fact not conscious (and that it is not the case that they are conscious or semi-conscious but later forget about their conscious experiences and are unable to report having had them). But we shall let these assumptions go by.

10 p. 177.

11 p. 179.

12 Perhaps consciousness is the result of genetic drift, or was once adaptive and is so no longer because of changed conditions. See footnote 5 and Ruse, p. 40.

13 Puccetti does convincingly argue that organisms for which every brain event were also sufficient for a mind-event would be comparatively disadvantaged. But this sort of isomorphism is obviously not required by the Identity Theory. Moreover it should be noted that this fact does not in and by itself render the isomorphism of every brain-state with some mental state incompatible with evolutionary theory. After all, this occurrence might be the result of pleiotropism. Mental and physical characteristics might be the result of a single pleiotropic gene.

14 p. 183.