ucceed each other with an
inconceivable rapidity, and are in a perpetual flux and movement. Our
eyes cannot turn in their sockets without varying our perceptions. Our
thought is still more variable than our sight; and all our other senses
and faculties contribute to this change; nor is there any single power
of the soul, which remains unalterably the same, perhaps for one moment.
The mind is a kind of theatre, where several perceptions successively
make their appearance; pass, re-pass, glide away, and mingle in an
infinite variety of postures and situations. There is properly no
simplicity in it at one time, nor identity in different; whatever
natural propension we may have to imagine that simplicity and identity.
The comparison of the theatre must not mislead us. They are the
successive perceptions only, that constitute the mind; nor have we the
most distant notion of the place, where these scenes are represented, or
of the materials, of which it is composed.

What then gives us so great a propension to ascribe an identity to
these successive perceptions, and to suppose ourselves possest of an
invariable and uninterrupted existence through the whole course of our
lives? In order to answer this question, we must distinguish betwixt
personal identity, as it regards our thought or imagination, and as it
regards our passions or the concern we take in ourselves. The first is
our present subject; and to explain it perfectly we must take the matter
pretty deep, and account for that identity, which we attribute to plants
and animals; there being a great analogy betwixt it, and the identity of
a self or person.

We have a distinct idea of an object, that remains invariable and
uninterrupted through a supposed variation of time; and this idea we
call that of identity or sameness. We have also a distinct idea of
several different objects existing in succession, and connected together
by a close relation; and this to an accurate view affords as perfect
a notion of diversity, as if there was no manner of relation among the
objects. But though these two ideas of identity, and a succession of
related objects be in themselves perfectly distinct, and even contrary,
yet it is certain, that in our common way of thinking they are generally
confounded with each other. That action of the imagination, by which we
consider the uninterrupted and invariable object, and that by which we
reflect on the succession of related objects, are almost t