Were it not for all this mental preparation, the illusory character of the performance would be too patent to view, and our enjoyment would suffer.  A man is often aware of this when coming into a theatre during the progress of a piece before his mind accommodates itself to the meaning of the play.  And the same thing is recognizable in the fact that the frequenter of the theatre has his susceptibility to histrionic delusion increased by acquiring a habit of looking out for the meaning of the performance.  Persons who first see a play, unless they be of exceptional imagination and have thought 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.