he sensation has little emotional colour, as in the
case of an ordinary sensation of sight or of articulate sound.

This being so, errors of introspection, supposing such to be found, will
in the main be sufficiently distinguished from those of perception. Even
an hallucination of sense, whether setting out from a subjective
sensation or not, always contains the semblance of a sense-impression,
and so would not be correctly classed with errors of introspection.

Just as introspection must be marked off from perception, so must it be
distinguished from memory. It may be contended that, strictly speaking,
all introspection is retrospection, since even in attending to a present
feeling the mind is reflectively representing to itself the immediately
preceding momentary experience of that feeling. Yet the adoption of this
view does not hinder us from drawing a broad distinction between acts of
introspection and acts of memory. Introspection must be regarded as
confined to the knowledge of immediately antecedent mental states with
reference to which, no error of memory can be supposed to arise.

It follows from this that an illusion of introspection could only be
found in connection with the apprehension of present or immediately
antecedent mental states. On the other hand, any illusions connected
with the consciousness of personal continuity and identity would fall
rather under the class of mnemonic than that of introspective error.

Once more, introspection must be carefully distinguished from what I
have called belief. Some of our beliefs may be found to grow out of and
be compounded of a number of introspections. Thus, my conception of my
own character, or my psychological conception of mind as a whole, may be
seen to arise by a combination of the results of a number of acts of
introspection. Yet, supposing this to be so, we must still distinguish
between the single presentative act of introspection and the
representative belief growing out of it.

It follows from this that, though an error of the latter sort might
conceivably have its origin in one of the former; though, for example, a
man's illusory opinion of himself might be found to involve errors of
introspection, yet the two kinds of illusion would be sufficiently
unlike. The latter would be a simple presentative error, the former a
compound representative error.

Finally, in order to complete this preliminary demarcation of our
subject-matter, it is necessary