The scale, properly speaking, does not permit the measure of the intelligence, because intellectual qualities are not superposable, and therefore cannot be measured as linear surfaces are measured.

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 do not attempt to establish or prepare a prognosis and we leave unanswered the question of whether this retardation is curable, or even improveable. We shall limit ourselves to ascertaining the truth in regard to his present mental state.

Could we look into the head of a Chess player, we should see there a whole world of feelings, images, ideas, emotion and passion

A few modern philosopher's assert that an individual's intelligence is a fixed quantity, a quantity which cannot be increased. We must protest and react against this brutal pessimism.... With practice, training, and above all, method, we manage to increase our attention, our memory, our judgment and literally to become more intelligent than we were before.

I wish that one would be persuaded that psychological experiments, especially those on the complex functions, are not improved [by large studies]; the statistical method gives only mediocre results; some recent examples demonstrate that. The American authors, who love to do things big, often publish experiments that have been conducted on hundreds and thousands of people; they instinctively obey the prejudice that the persuasiveness of a work is proportional to the number of observations. This is only an illusion.

Heredity, to our understanding is not capable of giving to this illness (paraphilia) its characteristic form ... Heredity invents nothing, creates nothing anew; it has no imagination.

A person may be a moron or an imbecile if he is lacking in judgment; but with good judgment he can never be either. Indeed the rest of the intellectual faculties seem of little importance in comparison with judgment.