This module aims to introduce students to the two major traditions within modern philosophy: rationalism and empiricism. The first half of the module will address Descartes' Meditations: the problem of scepticism and the 'evil demon' hypothesis: Descartes' "proofs" of the existence of God; mind-body dualism; the problem of error; and the nature of knowledge. The second half will address parts of Locke's Essay Concerning Human Understanding, covering topics such as the justification of belief in the external world; personal identity; the existence of God; primary and secondary qualities; real and nominal essences.