distinction has once been made (perhaps merely in consequence of the
difference observed between the ideas given us from without, and in
which we are passive, and those that we produce simply from ourselves,
and in which we show our own activity), then it follows of itself that
we must admit and assume behind the appearance something else that
is not an appearance, namely, the things in themselves; although we
must admit that as they can never be known to us except as they affect
us, we can come no nearer to them, nor can we ever know what they
are in themselves. This must furnish a distinction, however crude,
between a world of sense and the world of understanding, of which
the former may be different according to the difference of the
sensuous impressions in various observers, while the second which is
its basis always remains the same, Even as to himself, a man cannot
pretend to know what he is in himself from the knowledge he has by
internal sensation. For as he does not as it were create himself,
and does not come by the conception of himself a priori but
empirically, it naturally follows that he can obtain his knowledge
even of himself only by the inner sense and, consequently, only
through the appearances of his nature and the way in which his
consciousness is affected. At the same time beyond these
characteristics of his own subject, made up of mere appearances, he
must necessarily suppose something else as their basis, namely, his
ego, whatever its characteristics in itself may be. Thus in respect to
mere perception and receptivity of sensations he must reckon himself
as belonging to the world of sense; but in respect of whatever there
may be of pure activity in him (that which reaches consciousness
immediately and not through affecting the senses), he must reckon
himself as belonging to the intellectual world, of which, however,
he has no further knowledge. To such a conclusion the reflecting man
must come with respect to all the things which can be presented to