are united to our present by the bond of memory, the memory being accompanied by certain emotions. It is the present content of consciousness, which we interpret as the experience of a self that has been identical throughout changes. But the deceptiveness of memory is familiar to us all. The emotions that go with it give no infallible sign. Much of the past is omitted; something is added; and the complexion of the whole is changed. It is not quite our actual self with which we identify ourselves. It is our past, as altered and colored by memory. Moreover, grosser illusions as to personal identity are common. The insane man is convinced of his identity with Washington, or Shakespeare, or even with the Almighty. We need not inquire further into the nature of identity; we see the assumptions on which it is based. It is a judgment regarding the present content of consciousness, and one that may be erroneous.
But, it may be urged, men are endowed with a large number of intuitions, self-evident truths, laws of thought. Have we not in these a knowledge that can lay claim to certainty? Let us examine those intuitions as they have reference to real existence. Among such the intuition of space is usually ranked, and this instance is typical. It is meant that the soul directly sees space, or that it has a priori a notion of space, which corresponds to the actual space. Such an intuition is said to have necessity for thought. Yet it is assuming much to say that this conception is necessary. And even if it has a certain necessity, the necessity may be, so to speak, accidental. In order to walk we must use certain muscles, but other animals have other modes of locomotion. Space may be a necessity of our thinking, but this may be due to human peculiarities. But to prove that space has necessity, either of the first or second degree, is to know the constitution of our minds with a clearness and completeness of insight, to which as yet we can lay no claim.
But suppose it were, as Kant suggested, a necessity for all finite thinkers, and suppose we were certain of this, could we be certain of anything further? Are we obliged to regard
