This thesis examines aspects of Sigmund Freud's philosophy of mind, particularly with respect to his concept of unconscious mental events. Freud moved from psycho-physical dualism to a version of the identity theory in 1895. This transition coincided with, and provided the basis for his theory of unconscious mental events. Freud used a principle of mental continuity to provide philosophical support for his physicalistic theory of unconscious mental processes and to defend it against rival theories of neurophysiological dispositional ism and the dissociationism. The neuroscientist Jackson had a strong influence on the development of Freud's philosophical ideas. Freud eventually rejected Jackson's ontological dualism, although he ultimately retained Jackson's methodological dualism and anti-localisation ism. Freud's physicalistic theory of consciousness, which is intimately related to his theory of the unconscious, was set out in 1895, and the main features of this account were retained for the rest of his lifetime. Freud's concern with the neurophysiological ontology of mental items led him to take an anti-realist stance toward folk-psychological entities. His theory of mind is hospitable to homuncular· functionalism but incompatible with causal role functionalism. Freud advanced a thesis that the mental system that he called Ucs. is not governed by rational norms that raises problems for the attribution of mental contents to Ucs. John Searle has strongly criticised Freud's theory of mind and has used a form of neurophysiological dispositional ism to support his concept of the 'connection principle'. Searle's criticisms of Freud are unsound, and Freud's arguments against neurophysiological dispositional ism undermine Searle's argument on behalf of the connection principle. Donald Davidson attempts to philosophically underwrite Freud's theory of mind, but his split mind thesis does not capture Freud's distinctive theory and is vulnerable to criticism. Five appendices discuss matters of interest that would otherwise detract from the logical flow of the text. I have limited the scope of the present work to an investigation of a set of interlocking philosophical issues that were of concern to Freud and have been taken up by Searle and Davidson in relation to Freudian claims. Several important topics in the philosophy of psycho-analysis have therefore inevitably been touched upon only in a cursory fashion or ignored altogether.