it were otherwise, the major "_omne quod cogitat existit_"
would require to have been known before the minor "_cogito_"; whereas
on the contrary it is from the immediate consciousness of being as
contained in self-consciousness that that major can alone be derived.
Again, when Hobbes and others argued that thinking is or may be a
property of a material substance, Descartes answers that the question
whether the material and the thinking substance are one does not meet
us at the outset, but can only be solved after we have considered what
is involved in the conception of these different substances
respectively.[3] In other words, to begin by treating thinking as a
quality of a material substance, is to go outside of the intelligible
world for an explanation of the intelligible world. It is to ask for
something prior to that which is first in thought. If it be true that
the consciousness of self is that from which we cannot abstract, that
which is involved in the knowledge of anything, then to go beyond it
and seek for a reason or explanation of it in anything else is to go
beyond the beginning of knowledge; it is to ask for a knowledge before
knowledge.

Descartes, however, is himself unfaithful to this point of view; for,
strictly taken, it would involve the consequence, not only that there
is nothing prior to the pure consciousness of self, but that there can
be no object which is not in necessary relation to it. Hence there can
be no absolute opposition between thought and anything else, no
opposition which thought itself does not transcend. But Descartes
commits the error of making thought the property of a substance, a
_res cogitans_, which as such can immediately or directly apprehend
nothing but thoughts or ideas; while, altogether outside of these
thoughts and ideas, there is another substance characterized by the
property of extension, and with which thought has nothing to do.
Matter in space is thus changed, in Kantian language, into a "thing in
itself," an object out of all relation to the subject; and on the
other hand, mind seems to be shut up in the magic circle of its own
ideas, without any capacity of breaking through the circle or
apprehending any reality but itself. Between thought and being, in
spite of their _subjective_ unity in self-consciousness, a great gulf
seems still to be fixed, which cannot be crossed unless thought should