Comprehension, inventiveness, direction, and criticism: intelligence is contained in these four words.
It seems to me that people of talent and of genius serve better than average examples for making us understand the laws of character, because they present more extreme traits. Alfred Binet (1903)
Some recent philosophers seem to have given their moral approval to these deplorable verdicts that affirm that the intelligence of an individual is a fixed quantity, a quantity that cannot be augmented. We must protest and react against this brutal pessimism; we will try to demonstrate that it is founded on nothing. Les idées modernes sur les enfants (1909)