In place of earlier instrumentalist and phenomenalist interpretations of science both Quine and Sellars have developed highly influential realist positions centering around the doctrine that accepting a theory as explanatory and irreducible rationally entails accepting the entities posited by the theory. A growing reaction against this realism is partially based on perceived inadequacies in the doctrines of Quine and Sellars, but even more on reconstructions of scientific explanations which do not involve such ontic commitments. Three types of anti-realistic positions are considered and criticized. Hesse's neo-Duhemian position couples a statistical theory of inference to a downgrading of purely theoretical statements. Sneed uses the method of axiomatization through set-theoretic predicates to supply a reconstruction of Kuhn's account of scientific development. Here Ramsey-reduction sentences serve to eliminate purely theoretical terms. The longest section deals with van Fraassen's semantic model based on a state-space representation of scientific theories and the use of this model in interpreting quantum mechanics. It is argued that the model is valuable, but that the anti-realist interpretation accorded it is not justified and entails serious inconsistencies.

It is here argued that functionalist constraints on psychology do not preclude the applicability of classic forms of reduction and, therefore, do not support claims to a principled, or de jure, autonomy of psychology. In Part I, after isolating one minimal restriction any functionalist theory must impose on its categories, it is shown that any functionalism imposing an additional constraint of de facto autonomy must also be committed to a pure functionalist—that is, a computationalist—model for psychology. Using an extended parallel to the reduction of Mendelian to molecular genetics, it is shown in Parts II and III that, contrary to the claims of Hilary Putnam and Jerry Fodor, there is no inconsistency between computational models and classical reductionism: neither plurality of physical realization nor plurality of function are inconsistent with reductionism as defended by Ernest Nagel. Employing the results of Part I, the conclusions of Parts II and III are generalized in Part IV to cover any version of functionalism whatsoever; thus, functionalism and reductionism are shown to be consistent. It is urged in conclusion that although a de facto form of autonomy is defensible, there are sound methodological grounds for unconditionally rejecting any principled version of the autonomy of psychology.

Many philosophers, both past and present, object to materialism not from any romantic anti-scientific bent, but from sheer inability to understand the thesis. It seems utterly inconceivable to some that qualia should exist in a world which is entirely material. This paper investigates the grain objection, a much neglected argument which purports to prove that sensations could not be brain events. Three versions are examined in great detail. The plausibility of the first version is shown to depend crucially on whether one holds a direct or non-direct theory of perception. Only on the latter is this version plausible. An analysis of the second “semantic” version concludes that a materialist description and explanation of the world should not be expected to transparently convey all that would be of interest or importance to human beings. The final version explicitly makes use of Grover Maxwell's non-direct perceptual theory of structural realism. Although a confusion is charged to Maxwell between phenomenal and objective properties, the critical difficulty for the grain objection is its failure to characterize “structure” from a non-percipient point of view. As the grain objection is ultimately found wanting, the real difficulty for materialism crystallizes as its irreconciliability with the mere existence of sentience, which seems to force some sort of emergence upon us.

Richard Rorty's eliminative materialism is an attack on dualism that has frequently been misrepresented and incorrectly criticized. By taking account of the mistakes that philosophers have made concerning eliminative materialism, a proper definition of the doctrine and a clarification of its relation to traditional materialism will emerge, as well as an understanding of its true strengths and weaknesses. The discussion centers around the original manner in which Rorty defended eliminative materialism by means of analogies to the elimination of talk about demons and talk about macroscopic physical objects.

The fact that the names of biological species refer independently of identifying descriptions does not support the view of Ghiselin and Hull that species are individuals. Species may be regarded as natural kinds whose members share an essence which distinguishes them from the members of other species and accounts for the fact that they are reproductively isolated from the members of other species. Because evolutionary theory requires that species be spatiotemporally localized their names cannot occur in scientific laws. If natural kind status is denied to species on this ground, it must also be denied to most classes of concrete entities which are now accorded such status.