John Locke holds that matter is solid, the soul thinks, and for all we know the soul may be a material substance divinely endowed with a power to think. Though he openly admits to nothing stronger than the bare possibility of thinking matter, Locke grants that what thinks in us occupies a definite spatial location to the exclusion of other souls. Solidity is the quality that prevents other things from occupying a spatial location. Locke’s general criterion for identity is spatiotemporal (...) exclusion of other things of the same kind. To meet these conditions for identity, souls must be solid. Although Locke refuses to declare that souls really are material things, taking the solidity of souls to be a condition for their identity is consistent with the following of Locke’s other important commitments: nominalism about the essences by which substances are classified, agnosticism about the underlying reality of what supports such “nominal essences,” and the identity of persons is distinct from the identity of any substance. Locke ignores the implication that souls are solid because the solidity of souls is irrelevant to those three aims. Nevertheless he could allow for the solidity of souls without giving up on any of his other important and explicitly held commitments. There is therefore no need for Locke’s commentators to refrain from employing solidity in their accounts of Locke’s general criterion for identity from fear of attributing to Locke the position that souls would be solid. (shrink)

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)

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)

Seth Pringle-Pattison (233n1) observed that Locke “teaches a twofold mystery—in the first place, of the essence (‘for the powers or qualities that are observable by us are not the real essence of that substance, but depend upon it or flow from it’), and in the second place, of the substance itself (‘Besides, a man has no idea of substance in general, nor knows what substance is in itself.’ Bk. II.31.13).” In this paper, I’ll explain the relation between the two mysteries. (...) Our Rosetta Stone is Locke’s argument that we understand body and spirit equally well since we are ignorant of their underlying substances but we “have distinct clear Ideas of two primary Qualities, or Properties” (2.23.30) of each. I’ll show that he is working with a restricted notion of primary quality in this passage, but one that demonstrably falls under the kind defined in his chapter on primary and secondary qualities. According to Locke, the fundamental primary qualities of bodies flow from corporeal substances and the determinations of these fundamental qualities constitute real essences. Locke’s discussion can’t be understood without understanding the relevant scholastic background. In the first half of my paper, I’ll explain his argument as an idiosyncratic application of doctrines he learned and taught at Oxford. In the second half, I’ll use lessons from my interpretation of the argument to explain the relation that Locke believes obtains between a substance and its fundamental primary qualities, and then I’ll build upon that explanation to elucidate his general account (insofar as he has a general account) of the inherence of qualities in corporeal substances. (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)