got beyond them? This question leads us on
to philosophical problems of the greatest consequence, problems which
can only be very lightly touched in this place. Before approaching
these, let us look back a little more carefully and gather up our
results, reflect on the method which we have been unconsciously
adopting, and inquire how far this scientific mode of procedure will
take us in determining what is the whole range of illusory cognition.

We have found an ingredient of illusion mixed up with all the popularly
recognized forms of immediate knowledge. Yet this ingredient is not
equally conspicuous in all cases. First of all, illusion varies very
considerably in its degree of force and persistence. Thus, in general, a
presentative illusion is more coercive than a representative; an
apparent reality present to the mind is naturally felt to be more
indubitable than one absent and only represented. On the other hand, a
representative illusion is often more enduring than a presentative, that
is to say, less easily found out. It is to be added that a good deal of
illusion is only partial, there being throughout an under-current of
rational consciousness, a gentle play of self-criticism, which keeps the
error from developing into a perfect self-delusion. This remark applies
not only to the innocent illusions of art, but also to many of our
every-day illusions, both presentative and representative. In many
cases, indeed, as, for example, in looking at a reflection in a mirror,
the illusion is very imperfect, remaining in the nascent stage.

Again, a little attention to the facts here brought together will show
that the proportion of illusory to real knowledge is far from being the
same in each class of immediate or quasi-immediate cognition. Thus, with
respect to the great distinction between presentative and representative
knowledge, it is to be observed that, in so far as any act of cognition
is, strictly speaking, presentative, it does not appear to admit of
error. The illusions of perception are connected with the representative
side of the process, and are numerous just because this is so extensive.
On the other hand, in introspection, where the scope of independent
representation is so limited, the amount of illusion is very
inconsiderable, and may in practice be disregarded. So again, to take a
narrower group of illusions, we find that in the recalling of distant
events the proportion of error is vastly greater tha