can, of course, only be determined as
such in relation to some other act of introspection of the same mind. In
matters of internal perception other minds cannot directly assist us in
correcting error as they can in the case of external perception, though,
as we shall see by-and-by, they may do so indirectly. The standard of
reality directly applicable to introspective cognition is plainly what
the individual mind recognizes at its best moments, when the processes
of attention and classifying are accurately performed, and the
representation may be regarded with certainty as answering to the
feeling. In other words, in the sphere of internal, as in that of
external experience, the criterion of reality is the average and
perfect, as distinguished from the particular variable and imperfect act
of cognition.

We see, then, that error in the process of introspection is at least
conceivable. And now let us examine this process a little further, in
order to find out what probabilities of error attach to it.

To begin with, then, an act of introspection, to be complete, clearly
involves the apprehension of an internal feeling or idea as something
mental and marked off from the region of external experience. This
distinct recognition of internal states of mind as such, in opposition
to external impressions, is by no means easy, but presupposes a certain
degree of intellectual culture, and a measure of the power of abstract
attention.

_Confusion of Internal and External Experience._

Accordingly, we find that where this is wanting there is a manifest
disposition to translate internal feelings into terms of external
impressions. In this way there may arise a slight amount of habitual and
approximately constant error. Not that the process approaches to one of
hallucination; but only that the internal feelings are intuited as
having a cause or origin analogous to that of sense-impressions. Thus to
the uncultivated mind a sudden thought seems like an audible
announcement from without. The superstitious man talks of being led by
some good or evil spirit when new ideas arise in his mind or new
resolutions shape themselves. To the simple intelligence of the boor
every thought presents itself as an analogue of an audible voice, and he
commonly describes his rough musings as saying this and that to himself.
And this, mode of viewing the matter is reflected even, in the language
of cultivated persons. Thus we say, "The idea struck me