Amidst the progress being made in the various (sub-)disciplines of the behavioural and brain sciences a somewhat neglected subject is the problem of how everything fits into one world and, derivatively, how the relation between different levels of discourse should be understood and to what extent different levels, domains, approaches, or disciplines are autonomous or dependent. In this paper I critically review the most recent proposals to specify the nature of interdiscourse relations, focusing on the concept of supervenience. Ideally supervenience (...) is a relation between different discourses which has all the advantages of reduction, but without its disadvantages. I apply the more abstract considerations to two concrete cases: schizophrenia and colour. Usually an interlevel or interdiscourse relation is seen as asymmetrical: the overlaying discourse depends on the underlying discourse (and not vice versa), where the out- or un-spoken assumption is that the ultimate underlying discourse is physical. Instead I argue that scientific categories referred to in interdiscourse relations are, ultimately, dependent on common sense categories and common sense normative criteria. It is the manifest categories and common sense ideas about what is reasonable and what is right that determine the relevant categorisations at the deeper, underlying levels. I suggest that the implications of this are not merely methodological or epistemological. (shrink)

Supervenience is the impossibility of independent variation. A crude statement of supervenience would be the claim that things cannot differ in some respect without differing in some other respect. For example, to say that the mental supervenes on the physical is to say that there cannot be mental differences without physical differences. ;The basic idea behind supervenience can be developed in a number of ways. My dissertation contains a detailed study of the different supervenience relations found in the literature. I (...) consider their logical relations to one another and their relative strengths and weaknesses. I then develop new, more useful supervenience relations. ;In general, supervenience is supposed to be a nonreductive dependence relation. A primary goal of my dissertation is to determine the nature and philosophical significance of the dependence relation provided by supervenience. So, for example, I attempt to determine whether materialism is adequately formulated as a supervenience thesis. Recently, many have claimed that it is not. They claim that the mental could supervene on the physical without being asymmetrically dependent on the physical in the way that materialism requires. I respond by agreeing that supervenience is not sufficient for the relevant sort of dependence, but I contend that the supervenience of the mental on the physical is a nontrivial necessary condition on materialism. So the question of the supervenience of the mental on the physical is significant, for if it fails to hold, then materialism is false. Thus, I defend the importance of supervenience to philosophy while acknowledging that some of the recent criticisms of supervenience are sound. (shrink)