Subjects and Objects

Abstract

Is it a necessary condition of self-consciousness that one conceives of oneself as a physical object? On one interpretation, what makes an object a physical object is its possession of primary qualities such as shape, solidity and location. On this interpretation, a physical object is, in essence, a bounded spaceoccupier, and to conceive of oneself as a physical object is to conceive of the subject of one's thoughts and experiences as shaped, spatio-temporally located, and solid. I will refer to the claim that conceiving of oneself as a physical object in this sense is a necessary condition of self-consciousness as the physical object requirement on self-consciousness. A familiar neo-Kantian argument for the physical object requirement is this: in order to make and understand a judgement about something one must have the capacity to discriminate the object of one's judgement from all other things, and so must know what kind of thing one's judgement is about.' Thus, when a person self-ascribes an experience using I, she must be able to discriminate that to which she ascribes the experience from all other things, and so must know what kind of thing she is. Ex hypothesi, that to which the experience is ascribed is a person, and persons are in fact physical objects among physical objects. So if a self-conscious subject must be able to self-ascribe at least some of her experiences, and the comprehending selfascription of experiences requires substantive knowledge of what one is, then self-consciousness requires the conception of the subject of one's experiences as a physical object among physical objects.2 One way of getting to grips with Campbell's account of self-consciousness would be to ask whether and how it differs from the neo-Kantian account. One question is whether Campbell accepts the physical object requirement. If he does, then another question concerns the relationship between his argument for this requirement and the neo-Kantian argument. In connection with the first of these questions, an immediate complication is that