This work draws out the philosophical implications of European functionalist linguistics. It contains an account of human linguistic capacities through considering the role of languages in overall semiotic behaviour and the nature of our models of language and languages. It is particularly concerned with the nature of linguistically conveyed messages and their role in consciousness and with the methods for their understanding. The implications are related to an emergent anthropocentric philosophy and to metaphysics, epistemology in the wider sense, the philosophy of science and ethics. There is a special consideration of the limitations on human understanding which are due to the nature of our linguistic communication and our methods of analysis.