nificant, since the representation of a feeling or belief is so
very similar to the actual experience of it.

In brief, the errors of introspection, though numerous, are all too
slight to render the process of introspection as a whole unsound and
untrustworthy. Though, as we have seen, it involves, strictly speaking,
an ingredient of representation, this fact does not do away with the
broad distinction between presentative and representative cognition.
Introspection is presentative in the sense that the reality constituting
the object of cognition, the mind's present feeling, is as directly
present to the knowing mind as anything can be conceived to be. It may
be added that the power of introspection is a comparatively new
acquisition of the human race, and that, as it improves, the amount of
error connected with its operation may reasonably be expected to become
infinitesimal.

It is often supposed by those who undervalue the introspective method in
psychology that there is a special difficulty in the detection of error
in introspection, owing to the fact that the object of inspection is
something individual and private, and not open to common scrutiny as the
object of external perception. Yet, while allowing a certain force to
this objection I would point out, first of all, that even in
sense-perception, what the individual mind is immediately certain of is
its own sensations. The relatively perfect certainty which finally
attaches to the presentative side of sense-perception is precisely that
which finally attaches to the results of introspection.

In the second place, it may be said that the contrast between the inner
and the outer experience is much less than it seems. In many cases our
emotions are the direct result of a common external cause, and even when
they are not thus attached to some present external circumstance, we are
able, it is admitted, by the use of language, roughly to compare our
individual feelings. And such comparison is continually bringing to
light the fact that there is a continuity in our mental structure, that
our highest thoughts and emotions lead us back to our common
sense-impressions, and that consequently, in spite of all individual
differences of temperament and mental organization, our inner experience
is in all its larger features a common experience.

I may add that this supposition of the common nature of our internal
experience, as a whole, not only underlies the science of ps