THE UNITY OF IDENTITY AND DIFFERENCE AS THE ...

his conception of the substance as subject. It designates the general structures and
activities that constitute all genuine objects, including matter in its most general form,
plants, and the self. The problem posed by the opposition between the first and second
moment of the will simply present the highest instantiation of a more general problem,
one that occurs whenever we try to conceive any genuine object. In one of its most basic
forms, we can describe this problem in terms of the “unity of identity and difference.” In
order to conceive the structure of the notion, we must grasp the unity that includes, or
brings together, both identity and difference. This is the unity, “into which the
Understanding declines to advance.” It is a unity that only reason or speculation can
conceive. This unity is the “innermost secret of speculation,” the “ultimate spring of all
activity, life, and consciousness.” It is the notion, that which the understanding “persists
in calling the inconceivable.” It is the unity that must somehow be conceived in terms of
the unity of apperception or the “I think.”
47