Mohan Matthen

Byrne & Hilbert are right that it might be an objective fact that a particular tomato is unique red, but wrong that it cannot simultaneously be yellowish-red (not only objectively, but from somebody else's point of view). Sensory categorization varies among organisms, slightly among conspecifics, and sharply across taxa. There is no question of truth or falsity concerning choice of categories, only of utility and disutility. The appropriate framework for color categories is Nominalism and Pluralistic Realism.

This paper offers a new definition of "adaptationism". An evolutionary account is adaptationist, it is suggested, if it allows for multiple independent origins for the same function -- i.e., if it violates the "Unique Origin Constraint". While this account captures much of the position Gould and Lewontin intended to stigmatize, it leaves it open that adaptationist accounts may sometimes be appropriate. However, there are many important cases, including that of human rationality, in which it is not.

natural selection may show why all (most, some) humans have an opposable thumb, but cannot show why any particular human has one, Karen Neander ([1995a], [1995b]) argues that this is false because natural selection is 'cumulative'. It is argued here, on grounds independent of its cumulativity, that selection can explain the characteristics of individual organisms subsequent to the event. The difference of opinion between Sober and his critics turns on an ontological dispute about how organisms are identified and individuated. The assumption that Sober needs to make his point is extraneous to population genetics, and, for this reason, gratuitous.

Endogenous depression is highly correlated with low levels of serotonin in the central nervous system. Does this imply or suggest that this sort of depression just is this neurochemical deficit? Scorning such an inference, Antonio Damasio writes:If feeling happy or sad … corresponds in part to the cognitive modes under which your thoughts are operating, then the explanation also requires that the chemical acts on the circuits which generate and manipulate [such thoughts]. Which means that reducing depression to a statement about the availability of serotonin or norepinephrine in general- a popular statement in the days and age of Prozac- is unacceptably rude.Damasio's thought is that depression is essentially a modification of how we perceive the world, reason about it, and make decisions about how to act in it - in other words, that it is essentially cognitive. A reduced level of serotonin might cause the said modification, but no adequate account of depression would identify the malady with its cause. A proper account would minimally need to say how cognitive processing is affected by a reduced level of serotonin.

A main point of my article, as I see it, is that we can solve Putnam's problem, as articulated in the first paragraph of section three, without recourse to the definition of “natural-kind term” as “rigid designator of a natural kind”. I had three main objections to this definition: It makes the classification of a term as a natural-kind term dependent on one's metaphysics, i.e., on the status given to natural kinds. However, Putnam's argument seems to be independent of such metaphysical considerations, and the sort of natural kinds it establishes should be “read off its face”, not set down in advance. It permits the derivation of “exotic necessary truths” such as “If water is H20 then necessarily water is H20”. Putnam's main point appears to be about the independence of a term's extension from a linguistic community's beliefs. Why should this point affect the theory of designation? Kripke's argument about names establishes the non-descriptiveness of names while leaving undisturbed the classical conception of names designating individuals. Why should we not take his and Putnam's parallel arguments as establishing the non-descriptiveness of natural-kind terms while leaving undisturbed the classical conception of general terms designating classes?