When making the analysis of matter we impliedly admitted two propositions: first, that sensation is the tertium quid which is interposed between the … - Alfred Binet

It seems to us that in intelligence there is a fundamental faculty, the alteration or the lack of which, is of the utmost importance for practical life. This faculty is judgment, otherwise called good sense, practical sense, initiative, the faculty of adapting one's self to circumstances. 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.

"Never!" What a strong word! A few modern philosophers seem to lend their moral approval to these deplorable verdicts when they assert that an individual's intelligence is a fixed quantity, a quantity that cannot be increased. We must protest and react against this brutal pessimism. We shall attempt to prove that it is without foundation.

Comprehension, inventiveness, direction, and criticism: intelligence is contained in these four words.