February 29th, 2013
First, I explore John Locke’s conception of substance. After, I argue that Locke’s theory of substance is necessary for his theory of identity, and therefore philosophically vital for Locke’s ethical and political theories. I consider objections to Locke, but ultimately defend Locke’s theory of substance and its primacy in Locke’s overall philosophy through a different interpretive approach. Locke’s Substrata:
John Locke’s doctrine of substratum—a metaphysical theory that posits that an imperceptible substance underlies all objects—unites properties into one discrete object (I use ‘properties’ synonymously with ‘qualities’). Consider daily experience: we individuate an array of sensory data into discrete objects, mentally recording which properties seem to cluster. For instance, we perceive blackness, softness, and smallness all moving together in one shape and we assume these qualities make up the single object of a dog. However, we do not simply believe this cluster of properties is the object itself, but rather we believe the properties of the dog inhere in something—it stands to reason that we as humans do not simply believe that the qualities of objects could float off in space, rather we believe that the qualities of an object stick together. John Locke himself asserts, “substance in general contains properties” that must belong to something ((Locke Essay, II.viii.42). As Locke further states, qualities “cannot subsist…without something to support them" (Locke Essay, II.viii.41). We might look at substance a different way: certainly Locke maintains qualities belong to objects, but what are objects over and above their properties? Consider stripping an object of its properties: all that seems to be left is a bare ‘something,’ which on pains of regress, has no properties of its own, except the property of being the holder or supporter of other properties. Locke names this bare ‘something’ substratam—the metaphysical entity which holds the properties of a discrete object. Ultimately, as The Stanford Encyclopedia of Philosophy notes, “substance is he characterless substance that supports attributes of reality.
Objections to Locke’s Substance:
Critics, such as Ron Priest, argue that Locke’s doctrine of substratum is logically contradictory and therefore indefensible. Locke himself recognizes this glaring difficulty: “our Idea of Substance, is equally obscure ... in both instances of material as well as immaterial substance; it is but a supposed, I know not what, to support those Ideas, we call Accidents” (Locke Essay, II.viii.10). Locke states substratum is something ‘we know not what,’ which is something unknowable (Locke Essay, III.vii.8). Priest argues it defeats the purpose of invoking a substratum to suppose substratum capable of possessing properties of their own, rather than of the things whose substratum they were: for if things with properties need substrata to support these properties, then if substratum are themselves things with properties, they likewise will need yet other substrata in support of their properties and so on ad infinitum. Thus, it seems Locke’s concepts of substratum cannot be propertied, because that would require substratum ad infinitum as Priest argues. On the other hand, Locke’s conception of substance would at least need to possess the “property of being a bearer or supporter of properties” in order to fulfill its ontological role (Priest 114). If this is the case, then substratum cannot possibly be perfectly property-less. Therefore, substance must be both propertied and property-less. Thus Priest’s critique is that, on terms of contradiction, Locke’s substratum cannot exist.
However, Priest’s objection fails because it conflates one-place property predicates and relational predicates. Indeed, the definition of substratum requires the property...