and origin of the whole system of
human knowledge, Kant divides our intellectual being into _three_
distinct faculties,--sensation, understanding, and reason. He supposes
that from sensation we derive the whole _matter_ of our knowledge; that
from the understanding we derive its _form_, or the manner in which it
is conceived of by us; and that from reason we derive certain general or
abstract notions, which are highly useful, since they give a systematic
unity to human thought, but which have no _objective validity_, that is,
either no reality in nature that corresponds to them, or none, at least,
that can be scientifically demonstrated. From this fundamental principle
of his system it follows, that the only part of our knowledge which has
any objective reality is that which is derived from our
sense-perceptions, all else being purely _formal or subjective_, and
arising solely from the laws of our own mental nature, which determine
us to conceive of things in a particular way; and that even that part of
our knowledge which is derived from sense-perception is purely
phenomenal, since we know nothing of any object around us beyond the
bare fact that it exists, and that it appears to us to be as our senses
represent it. Hence the _skeptical_ tendency of Kant's speculations, in
so far as the scientific certainty of our knowledge is concerned. The
_practical utility_ of that knowledge is not disputed, but its
_objective reality_, or the possibility of proving it, is, to a large
extent, denied. Still he admits a primitive _dualism_, and a radical
distinction between _the subject and the object_, between the mind which
thinks and the matter of its thoughts. The _matter_ comes from without,
the _form_ from within; and the senses are the channels through which
the phenomena of nature are poured into the mould of the human mind. All
knowledge implies this combination of _matter_ with _form_, and is
possible only on the supposition of the concurrent action both of the
_object_ and _subject_; not that either of the two is known to us in its
essence, or that their real existence can be scientifically
demonstrated, for we know the subject only in its relation to the
object, and the object only in its relation to the subject; but that
this _relation_ necessarily requires the joint action of both, by which
alone we can acquire the only knowledge of which we are capable, and
which is supposed to be purely phenomenal, relative, and subject