t much about the theatre--as
Charlotte Bronte, for instance--hardly feel the illusion at all. At
least, this is true of the opera, where the departure from reality is
so striking that the impression can hardly fail to be a ludicrous one,
till the habit of taking the performance for what it is intended to be
is fully formed.[51]

A similar effect of intellectual preadjustment is observable in the
fainter degrees of illusion produced by pictorial art. Here the
undeceiving circumstances, the flat surface, the surroundings, and so
on, would sometimes be quite sufficient to prevent the least degree of
illusion, were it not that the spectator comes prepared to see a
representation of some real object. This is our state of mind when we
enter a picture gallery or approach what we recognize as a picture on
the wall of a room. A savage would not "realize" a slight sketch as soon
as one accustomed to pictorial representation, and ready to perform the
required interpretative act.[52]

So much as to the effect of an indefinite state of sub-expectation in
misleading our perceptions. Let us now glance at the results of definite
preimagination, including what are generally known as expectations.

_Effects of Vivid Expectation._

Such expectations may grow out of some present objective facts, which
serve as signs of the expected event; or they may arise by way of verbal
suggestion; or, finally, they may be due to internal spontaneous
imagination.

In the first place, then, the expectations may grow out of previous
perceptions, while, nevertheless, the direction of the expectation may
be a wrong one. Here the interpreting imagination is, in a large sense,
under the control of external suggestion, though, with respect to the
particular impression that is misconstrued, it may be regarded as acting
independently and spontaneously.

Illustrations of this effect in producing illusion will easily occur to
the reader. If I happen to have heard that a particular person has been
a soldier or clergyman, I tend to see the marks of the class in this
person, and sometimes find that this process of recognition is
altogether illusory. Again, let us suppose that a person is expecting a
friend by a particular train. A passenger steps out of the train bearing
a superficial resemblance to his friend; in consequence of which he
falls into the error of false identification.

The delusions of the conjuror depend on a similar principle. The
performe