Abstract

This thesis examines the epistemological and metaphysical aspects of consciousness or sentience, and how they relate to standards of scientific practice. Historically, orthodox science has denied that there are any real problems of sentience because there is no scientific evidence to support claims regarding its nature and existence. In recent years, however, new approaches to sentience have entered into scientific debate that can be classified by metaphysical frameworks that vary in their conceptions of scientific evidence. In this thesis, four such frameworks are considered and compared: Ordinary Materialism, Property Dualism, Type-F Monism and Phenomenal Representationalism. Many sentience theorists adopt an Ordinary Materialist framework that conceives of scientific observation as the interaction of our physical sensory apparatus with the surrounding physical world. Sentience-friendly theories in this framework fail to present supporting evidence that is acceptable by ordinary scientific standards. There are also contradictions in their claims that we know of conscious events via naturalised introspection, and their claims that these events create no publicly observable physical effects. Theories proposed within Property Dualist and Type-F Monist frameworks suffer from similar problems to Ordinary Materialist theories, especially contradictions between claims of knowledge by direct acquaintance and how this knowledge is stored and processed by publicly observable physical systems. Phenomenal Representationalism is advocated as the most consistent and complete way for science to deal with questions of sentience. In this framework, questions of sentience are part of wider epistemological concerns that provide presumptions for scientific practice, rather than subjects for scientific investigation.