y are, i. e. as they
are independently of perception. Again, since the reality which we
desire to know consists of individuals, and since the apprehension of
an individual implies perception, knowledge of reality requires
perception. If in perception we apprehended reality as it is, no
difficulty would arise. But we do not, for we are compelled to
distinguish what things are, and what they look or appear; and what
they appear essentially relates to perception. We perceive them as
they look or appear and, therefore, not as they are, for what they
look and what they are are _ex hypothesi_ distinguished. And this fact
constitutes a fatal obstacle to knowledge in general. We cannot know
anything as it _is_. At least the negative side of Kant's position
must be justified. We never can know things as they are in themselves.
What then do we know? Two alternative answers may be given. It may be
held that the positive side of Kant's position, though indefensible in
the form that we know things as they appear to us, is valid in the
form that we know what things look or appear. This, no doubt, implies
that our ordinary beliefs about reality are illusory, for what things
look is _ex hypothesi_ different from what they are. But the
implication does not constitute an important departure from Kant's
view. For in any case only that is knowledge proper which relates to
things as they are, and therefore the supposed knowledge of things as
they appear may be discarded without serious loss. On the other hand,
it may be held that the positive side of Kant's position can be
vindicated in the form that, while we do not know things in
themselves,[10] we do know the appearances which they produce in us.
It is true that this view involves the difficulty of maintaining that
appearances are spatial, but the difficulty is not insuperable.
Moreover, in this form the doctrine has the advantage that, unlike the
former, it does not imply that the knowledge which we have is only of
illusions, for instead of implying that our knowledge is merely
knowledge of what things look but really are not, it implies that we
know the real nature of realities of another kind, viz. of
appearances. Again, in this form of the view, it may be possible to
vindicate Kant's doctrine that the distinction between the real and
the illusory is tenable within what we know, for it may be possible to
distinguish within appearances between a 'real' appearance[11] and an
'illusory'