Illusions: A Psychological Study

by James Sully

A little inquiry into the mental operations which I here include under the name belief will show, however, that they are by no means uniformly process of inference. To take the simplest form of such knowledge, anticipation of some personal experience: this may arise quite apart from recollection, as a spontaneous projection of a mental image into the future. A person may feel "intuitively certain" that something is going to happen to him which does not resemble anything in his past experience. Not only so; even when the expectation corresponds to a bit of past experience, this source of the expectation may, under certain circumstances, be altogether lost to view, and the belief assume a secondarily automatic or intuitive character. Thus, a man may have first entertained a belief in the success of some undertaking as the result of a rough process of inference, but afterwards go on trusting when the grounds for his confidence are wholly lost sight of.

This much may suffice for the present to show that belief sometimes approximates to immediate, or self-evident, conviction. How far this is the case will come out in the course of our inquiry into its different forms. This being so, it will be needful to include in our present study the errors connected with the process of belief in so far as they simulate the immediate instantaneous form of illusion.

What I have here called belief may be roughly distinguished into simple and compound belief. By a simple belief I mean one which has to do with a single event or fact. It includes simple modes of expectation, as well as beliefs in single past facts not guaranteed by memory. A compound belief, on the other hand, has reference to a number of events or facts. Thus, our belief in the continued existence of a particular object, as well as our convictions respecting groups or classes of events, must be regarded as compound, since they can be shown to include a number of simple beliefs.

A. Simple Illusory Belief: Expectation.

It will be well to begin our inquiry by examining the errors connected with simple expectations, so far as these come under our definition of illusion. And here, following our usual practice, we may set out with a very brief account of the nature of the intellectual process in its correct form. For this purpose we shall do well to take a complete or definite anticipation of an event as our type.[136]

The ability of the mind to move forward, forecasting an order of events in time, is clearly very similar to its power of recalling events. Each depends on the capability of imagination to represent a sequence of events or experiences. The difference between the two processes is that in anticipation the imagination setting out from the present traces the succession of experiences in their actual order, and not in the reverse order. It would thus appear to be a more natural and easy process than recollection, and observation bears out this conclusion. Any object present to perception which is associated with antecedents and consequents with the same degree of cohesion, calls up its consequents rather than its antecedents. The spectacle of the rising of the sun carries the mind much more forcibly forwards to the advancing morning than backwards to the receding night. And there is good reason to suppose that in the order of mental development the power of distinctly expecting an event precedes that of distinctly recollecting one. Thus, in the case of the infant mind, as of the animal intelligence, the presence of signs of coming events, as the preparation of food, seems to excite distinct and vivid expectation.[137]

As a mode of assurance, expectation is clearly marked off from memory, and is not explainable by means of this. It is a fundamentally distinct kind of conviction. So far as we are capable of analyzing it, we may say that its peculiarity is its essentially active character. To expect a thing is to have stirred the active impulses, including the powers of attention; it is to be on the alert for it, to have the attention already focussed for it, and to begin to rehearse the actions which the actual happening of the event—for example, the approach of a welcome object—would excite. It thus stands in marked contrast to memory, which is a passive attitude of mind, becoming active only when it gives rise to the expectation of a recurrence of the event.[138]

And now let us pass to the question whether expectation ever takes the form of immediate knowledge. It may, perhaps, be objected that the anticipation of something future cannot be knowledge at all in the sense in which the perception of something present or the recollection of something past is knowledge. But this objection, when examined closely, appears to be frivolous. Because the future fact has not yet come into the sphere of actual existence, it is none the less the object of a perfect assurance.[139]

But, even if it is conceded that expectation is knowledge, the objection may still be urged that it cannot be immediate, since it is the very nature of expectation to ground itself on memory. I have already hinted that this is not the case, and I shall now try to show that what is called expectation covers much that is indistinguishable from immediate intuitive certainty, and consequently offers room for an illusory form of error.

Let us set out with the simplest kind of expectation, the anticipation of something about to happen within the region of our personal experience, and similar to what has happened before. And let the coming of the event be first of all suggested by some present external fact or sign. Suppose, for example, that the sky is heavy, the air sultry, and that I have a bad headache; I confidently anticipate a thunderstorm. It would commonly be said that such an expectation is a kind of inference from the past. I remember that these appearances have been followed by a thunderstorm very often, and I infer that they will in this new case be so followed.