Online research in philosophy

Paul Churchland's philosophical work enjoys an increasing popularity. His imaginative papers on cognitive science and the philosophy of psychology are widely discussed. Scientific Realism and the Plasticity of Mind (1979), his major book, is an important contribution to the debate on realism. Churchland provides us with the intellectual tools for constructing a unified scientific Weltanschauung. His network theory of language implies a provocative view of the relation between science and common sense. This paper contains a critical examination of Churchland's network theory of language, which is the foundation of his philosophy. It is argued that the network theory should be seen as deriving its point from traditional empiricism. The network theory enables the empiricist to resist the phenomenalistic temptations inherent in his position, and to build a realist philosophy on the basis of the representative theory of perception. This interpretation is confirmed by the fact that the representative theory is presupposed by Churchland's main argument in favour of the network view. Churchland tends to conceive of himself as a naturalistic epistemologist. But the philosophical faction to which Churchland belongs is rather that of modern neo?Kantianism.

The present essay is addressed simultaneously to two distinct audiences.

Recent research into the evolution of higher cognition has piqued an interest in the effect of natural selection on the ability of creatures to respond to their environment (behavioral plasticity). It is believed that environmental variation is required for plasticity to evolve in cases where the ability to be plastic is costly. We investigate one form of environmental variation: frequency dependent selection. Using tools in game theory, we investigate a few models of plasticity and outline the cases where selection would be expected to maintain it. Ultimately we conclude that frequency dependent selection is likely insuffcient to maintain plasticity given reasonable assumptions about its costs. This result is very similar to one aspect of the well-discussed Baldwin effect, where plasticity is first selected for and then later selected against. We show how in these models one would expect plasticity to grow in the population and then be later reduced. Ultimately we conclude that if one is to account for the evolution of behavioral plasticity in this way, one must appeal to a very particular sort of external environmental variation.

Recent research into the evolution of higher cognition has piqued an interest in the effect of natural selection on the ability of creatures to respond to their environment (behavioral plasticity). It is believed that environmental variation is required for plasticity to evolve in cases where the ability to be plastic is costly. We investigate one form of environmental variation: frequency dependent selection. Using tools in game theory, we investigate a few models of plasticity and outline the cases where selection would be expected to maintain it. Ultimately we conclude that frequency dependent selection is likely insufficient to maintain plasticity given reasonable assumptions about its costs. This result is very similar to one aspect of the well-discussed Baldwin effect, where plasticity is first selected for and then later selected against. We show how in these models one would expect plasticity to grow in the population and then be later reduced. Ultimately we conclude that if one is to account for the evolution of behavioral plasticity in this way, one must appeal to a very particular sort of external environmental variation. Keywords: Game theory, Evolutionarily stable strategy, Behavioral plasticity..

It is very tempting to try to reconcile perception and cognition perceptual symbol systems may be a good way to achieve this; but is there actually a perception-cognition continuum? We offer several arguments for and against the existence of such a continuum and in favor of the choice of perceptual symbol systems. One of these arguments is purely theoretical, some are based on PET-scan observations and others are based on research with handicapped subjects who have communication problems associated with cerebral lesions. These arguments suggest that modal perceptual symbols do indeed exist and that perception and cognition might have a common neuronal basis; but perceptual and cognitive activities require the activation of different neuronal structures.

Paul Churchland has become famous for holding three controversial and interrelated doctrines which he put forward in early papers and in his first book. Scientific Realism and the Plasticity of Mind (1979): eliminative materialism, the doctrine of the plasticity of perception, and a general network theory of language. In his latest book, The Engine of Reason, the Seat of the Soul (1995), Churchland aims to make some results of connectionist neuroscience available to the general public and explores the philosophical and social consequences that neuroscience is likely to have. I argue that these results of neuroscience refute the three doctrines that Churchland advocated in his earlier works. Yet youthful dreams do not die easily and Churchland is reluctant to relinquish his early views.

In this paper I argue that because Churchland does not adequately address the distinction between high-level cognitive theories and low-level embodied theories, Churchland's claims for theory-laden perception lose their epistemological significance. I propose that Churchland and others debating the theory-ladenness of perception should distinguish carefully between two main ways in which perception is plastic: through modifying our high-level theories directly and through modifying our low-level theories using training experiences. This will require them to attend to two very different types of constraints on the modification of our perceptions.

The basic problem of perceptual change is how to account for both variation and constancy in perceiving the world. Is order learned? How deep does plasticity go in that respect? I argue that different kinds of perceptual plasticity have been confused in recent debates, notably between J. Fodor and P. M. Churchland. By focusing on changes in the use of concepts, the issues in the Fodor-Churchland debate can be resolved. Beyond that debate, I propose a generalized encoding approach to perception as a way of accounting for a significant form of perceptual change.

The doctrine that the character of our perceptual knowledge is plastic, and can vary substantially with the theories embraced by the perceiver, has been criticized in a recent paper by Fodor. His arguments are based on certain experimental facts and theoretical approaches in cognitive psychology. My aim in this paper is threefold: (1) to show that Fodor's views on the impenetrability of perceptual processing do not secure a theory-neutral foundation for knowledge; (2) to show that his views on impenetrability are almost certainly false; and (3) to provide some additional arguments for, and illustrations of, the theoretical character of all observation judgments.