This thesis evaluates a variety of important modern approaches to the study of the mind/brain in the light of recent developments in the debate about how evidence should be used to support a theory and its constituent hypotheses. Although all these approaches are ostensibly based upon the principles of scientific realism, this evaluation will demonstrate that all of them fall well short of these requirements. Consequently, the more modern, co-evolutionary theories of the mind/brain do not constitute the significant advance upon (...) more traditional theories that their authors take them to be. There are two fundamental elements within my discussion of the relationship between evidence and the constituent hypotheses of a theory. Firstly, I shall demonstrate that the traditional veil-of-perception issue has a wider relevance than that which has historically been attributed to it, since it is the paradigm case of an attempt to construct a two level theory on the basis of evidence tha~ does not adequately support either hypothesis. This interpretation of the issue can be represented by constructing a semantically inconsistent tetrad. It is shown that similar tetrads can be constructed for each of the theories of the mind/brain discussed in this thesis. Secondly, I shall argue that the theories discussed all employ a variety of the bootstrap strategy. This strategy is a relatively recent development in the philosophy of science, which suggests a way in which the same evidence can be used to generate both a general and a specific hypothesis within a theory without violating the constraints of scientific realism. However, I contend that recent use of this strategy in the investigation of mind is largely unsatisfactory as a result of a neglect of structural as well as more informal influences upon the kinds of evidence employed to support the hypotheses contained in the theories. The thesis is divided into three major sections. The first (Section A) discusses the influence of the motivations of the individual theorists upon their arguments and provides a critical discussion of the issues of the veil-of-perception and bootstrapping. The second section (Section B) comprises a detailed examination of a range of modern theories of the mind/brain and critically analyses their success. The final section (Section C) draws together general conclusions and methodological consequences of the detailed analysis of the nature of realism and evidence in the philosophy of mind. (shrink)