H. Taine, Popular Science Monthly (1876)
“ It is easily seen that, commencing with the fifth or sixth month, infants, during the succeeding two years or more, give all their time to making experiments in natural philosophy. There is no animal, not even the cat or the dog, which makes such continual study of all bodies within its reach. Every day, the infant of whom I speak (age twelve months) touches, feels, turns over, lets fall, tastes, and experiments upon, whatever comes under its hand; whatever the object may be—a ball, doll, rattle, toy—once it is sufficiently known, the infant leaves it alone: it is no longer a novelty ”
