however, the active
and passive factors seem to combine. There are certain intricacies in
the mental phenomenon itself favouring the chances of error, and there
are independent predispositions leading the mind to look at the
phenomenon in a wrong way. This seems to apply to the famous declaration
of a certain school of thinkers that by an act of introspection we can
intuit the fact of liberty, that is to say, a power of spontaneous
determination of action superior to and regulative of the influence of
motives. It may be plausibly contended that this idea arises partly
from a mixing up of facts of present consciousness with inferences from
them, and partly from a natural predisposition of the mind to invest
itself with this supreme power of absolute origination.[106]

In a similar way, it might be contended that other famous philosophic
dicta are founded on a process of erroneous introspection of subjective
mental states. In some cases, indeed, it seems a plausible explanation
to regard these illusions as mere survivals in attenuated shadowy form
of grosser popular illusions. But this is not yet the time to enter on
these, which, moreover, hardly fall perhaps under our definition of an
illusion of introspection.

_Value of the Introspective Method._

In drawing up this rough sketch of the illusions of introspection, I
have had no practical object in view. I have tried to look at the facts
as they are apart from any conclusions to be drawn from them. The
question how far the liability to error in any region of inquiry
vitiates the whole process is a difficult one; and the question whether
the illusions to which we are subject in introspection materially affect
the value of self-knowledge as a whole and consequently of the
introspective method in psychology, as many affirm, is too subtle a one
to be fully treated now. All that I shall attempt here is to show that
it does not do this any more than the risk of sense-illusion can be said
materially to affect the value of external observation.

It is to be noted first of all that the errors of introspection are much
more limited than those of sense-perception. They broadly answer to the
slight errors connected with the discrimination and recognition of the
sense-impression. There is nothing answering to a complete hallucination
in the sphere of the inner mental life. It follows, too, from what has
been said above, that the amount of active error in introspection is
insig