pal characteristics, unity and identity, this latter merging into unity, for it is nothing else but the persistence of unity through the course of time. Certain philosophers have asserted that through intuition we can all establish that we are a spiritual substance. I am compelled to reject this idea, because I think the expression spiritual substance has no meaning; nothing but the sonorous value of six syllables. It has also been supposed, that there exists a corporeal substance hidden under the sensations, in which are implanted the qualities of bodies, as the various organs of a flower are in its calyx. I will return later to this conception of a material substance. That of a spiritual substance cannot be defended, and the chief and fatal argument I urge against it is, that we cannot represent it to our minds, we cannot think it, and we cannot see in these words “spiritual substance” any intelligible idea; for that which is mental is limited to “that which is of the consciousness.” So soon as we endeavour to go beyond the fact of having consciousness to imagine a particular state which must be mental, one of two things happen; either we only grasp the void, or else we construct a material and persistent object in which we recognise psychical attributes. These are two conclusions which ought to be rejected.