The world is but an assembly of present, past, and possible sensations; the affair of science is to analyze and co-ordinate them by separating their … - Alfred Binet

This test thought out and proposed by Professor Ebbinghaus of Berlin, varies in significance according to its mode of use. It consists essentially in this: a word of a text is omitted and the subject is asked to replace it. The nature of the intellectual work by which the gap is filled, varies according to the case. This may be a test of memory, a test of style, or a test of judgment. In the sentence: ‘Louis IX was born in ——‘ the gap is filled by memory. ‘The crow —– his feathers with his beak’; in this the idea of the suppressed word is not at all obscure, and the task consists in finding the proper word. We may say in passing, that according to the opinion of several teachers before whom we have tried it, this kind of exercise furnishes excellent scholastic training. Lastly, in sentences of the nature of those we have chosen, the filling of the gaps requires an attentive examination and an appreciation of the facts set forth by the sentence. It is therefore an exercise of judgment.

Before explaining these methods let us recall exactly the conditions of the problem which we are attempting to solve. Our purpose is to be able to measure the intellectual capacity of a child who is brought to us in order to know whether he is normal or retarded. We should therefore, study his condition at the time and that only. We have nothing to do either with his past history or with his future; consequently we shall neglect his etiology, and we shall make no attempt to distinguish between acquired and congenital idiocy; for a stronger reason we shall set aside all consideration of pathological anatomy which might explain his intellectual deficiency. So much for his past. As to that which concerns his future, we shall exercise the same abstinence; we do not attempt to establish or prepare a prognosis and we leave unanswered the question of whether this retardation is curable, or even improvable. We shall limit ourselves to ascertaining the truth in regard to his present mental state.

We are, for the rest, so wrapped up in sensations that none of our boldest conceptions can break through the circle.