In this paper, I will argue that Locke is a substance dualist in the general sense, in that he holds that there are, independent of our classificatory schema, two distinct kinds of substances: wholly material ones and wholly immaterial ones. On Locke’s view, the difference between the two lies in whether they are solid or not, thereby differentiating him from Descartes. My way of establishing Locke as a general substance dualist is to be as minimally committal as possible at the (...) outset, especially with respect to the classic debates on Locke’s positions in this domain, including those concerning substrata, real essences, and the like. Nonetheless, I show that minimal commitments about Locke’s primary/secondary quality distinction are sufficient to derive some substantive conclusions about his positions on these issues, as well as that he is a general substance dualist. (shrink)

I argue that Locke’s distinction between ‘determined’ and ‘undetermined’ ideas incorporates an account of semantic indeterminacy: if the complex idea to which a general term is annexed is ‘undetermined’, the term lacks a determinate extension. I propose that a closer look at this account of semantic indeterminacy illuminates various charges of confusion, misuse and abuse of language Locke levels against his philosophical contemporaries.

The paper argues against the claim held, e.g., by Leibniz, that Locke employs a double standard for determining whether an object before the mind (i.e., an idea) is real. Using Locke's ectype-archetype distinction it is shown that this charge is the result of confusing Locke's criterion of reality with its application. Depending on whether it applies to a simple, substance or mode idea, the criterion works out differently. Next it is argued that although Locke maintains only a single criterion, this (...) criterion is untenable, since it fails to properly distinguish real from fantastical ideas. (shrink)

Locke's claims about the "inadequacy" of substance-ideas can only be understood once it is recognized that the "sort" represented by such an idea is not wholly determined by the idea's descriptive content. The key to his compromise between classificatory conventionalism and essentialism is his injunction to "perfect" the abstract ideas that serve as "nominal essences." This injunction promotes the pursuit of collections of perceptible qualities that approach ever closer to singling out things that possess some shared explanatory-level constitution. It is (...) in view of this norm regulating natural-historical inquiry that a substance-idea represents a sort for which some such constitution serves as the "real essence," i.e. as that on which all the sort's characteristic "properties" depend. (shrink)

John Locke famously claimed that our idea of substance is but a confused idea of “something we know not what.” However, he also thought that the idea of substance is a fundamental part of our ideas of ourselves and the objects surrounding us—of objects we do know. Interpreting this apparently ambivalent stance has long been a major challenge for Locke scholarship. In this article, I argue that the leading interpretations of Locke's conception of substance have failed to resolve this tension (...) because they have misconstrued the source of Locke's skepticism about our knowledge of what substance is. This skepticism, I argue, issues from an observation about the signification of the term “substance”: Locke maintained that the philosophical usage of the term is irremediably equivocal. This reading allows us to acknowledge that Locke could consistently hold that ordinary objects, such as persons, horses, or trees, are paradigmatic examples of substances. It also points to a better appreciation of how Locke's discussion of substance relates to the scholastic conceptions of substance he tried to overcome. (shrink)

In this paper, we intend to offer an interpretation about the explanation of the (relative) idea of pure substance in general on John Locke’s philosophy, from Thomas Reid’s notion of ‘natural suggestion’. To achieve this aim, after contextualizing Locke’s notion of pure substance in general and distinguishing it from the idea of particular substance (section 1), we explicit that Locke’s words about the source of the idea of the former in the mind (either empirical or rational) are ambiguous and inconclusive (...) (section 2). Then, we argue that the parallels between this idea and that of ‘relation’, as well as of ‘power’ do not assist in that answer, due to some problems we identify on them (section 3). Finally, we argue that the Reidian explanation for the source of the idea of ‘mind’, from the notion of ‘natural suggestion’ allows us to i) avoid those problems and ii) inasmuch as, according to this interpretation, the idea of pure substance in general would have an empirical source, Lockian empiricism would remain intact (section 4). (shrink)

This paper derives the essence of a substance (i.e., the nominal essence) and its content by respectively discussing substance and real essence, substance and nominal essence, providing an answer to the question: “What certainty can substance derive from Locke’s description of essence”. Substance and real essences answer different questions, and the idea of explaining substance in terms of real essence (as represented by Michael Ayers) is not feasible; the true essence of the substance is nominal essence, from which the substance (...) derives only the meaning of substance’s name, and this meaning cannot be fully revealed, so that one does not have complete knowledge of the essence of substance. Overall, we know very little about substance and the content of their essences (nominal essences), this negative result provides a new perspective on empirical agnosticism. (shrink)

Locke, in his discussion of essences, makes extensive use of a distinction he introduces between nominal and real essences. This distinction has always been found interesting and important, and in fact, R.I. Aaron said of it that ‘there is no more important distinction in the Essay.’ Nevertheless, to say there has not been general agreement about what Locke was getting at is putting it mildly. Interpretations of Locke's point in making such a distinction have varied widely, depending upon whether the (...) importance of the real or the nominal essence is stressed. Locke tells us we should distinguish the nominal essence, which is the abstract idea to which a general name is attached and for which it stands, from the real essence, which is the ‘real internal, but generally in Substances, unknown Constitution of Things, whereon their discoverable Qualities depend.’. (shrink)

in The Cambridge Companion to Locke’s Essay, edited by Lex Newman. Cambridge: Cambridge University Press, 2007.