Abstract

It has long been recognized that 'idea' was Locke's central epistemological concept. So important was it that most commentators consider it necessary to first fix what that concept was before attempting to interpret Locke's epistemology. However, identifying what it was is only possible by reconstructing how it functioned within the development and defense of his epistemology. Traditionally, in other words, scholars have approached the question the wrong way around. This dissertation is devoted to the first step of such a reconstruction, recovering the nature of the ideational understructure---what Locke called Semeiotike---infixed into and informing his epistemology. ;Semeiotike was the doctrine of signs, of which Locke recognized two types: ideas and words. Word-signs were, for Locke, significant yet it was his semiotic of idea-signs that was, philosophically, the most basic; thus that is the cynosure of this dissertation. Two basic doctrines comprised Locke's semiotic: psychological empiricism and ideational semantics. Locke, it is argued, melded an empirical account of ideas as psychological elements, an account taken from his understanding of ancient medical empiricism , to the termist semantics of the late Scholastics. This melding produced something altogether new, a semiotic neither Scholastic nor empiric, one utterly unique but retaining many of the hallmarks of both. ;In the dissertation's first part Locke's empirical psychology is addressed. After examining the failure of the debate about ideas, new interpretations of Locke's attack on innatism, his defense of empiricism, and his historical plain method are proffered. Furthermore, it is argued that abstraction was, for Locke, a form of non-inferential experience and that reflection and sensation were both representational, but in a very different way than scholars have taken them to be. In the second part ideational semantics is addressed. A logical interpretation of Lockean simplicity is defended followed by close examinations of how his complex ideas were constructed out of those simple semantic elements. Finally, it is shown how the properties of ideas---clarity, distinctness, reality, adequacy, and truth---follow from their semantics