Comenius and Rousseau both emphasized the fact that school systems must be made for children, and not children for school systems. Neither reformer shared the schoolmaster’s customary contempt for childhood, but both urged that childhood must be studied and loved to be understood and trained, and both, if they had lived in the nineteenth and twentieth centuries, would have been enthusiastic advocates of child study. Says Rousseau: “We do not understand childhood, and pursuing false ideas of it, our every step takes us farther astray. The wisest among us fix upon what it concerns men to know, without ever considering what children are capable of learning. They always expect to find the man in the child, without thinking of what the child is before it is a man.... We never know how to put ourselves in the place of children; we do not enter into their ideas; we attribute to them our own; and following always our own train of thought, even with syllogisms, we manage to fill their heads with nothing but extravagance and error.... I wish some discreet person would give us a treatise on the art of observing children—an art which would be of immense value to us, but of which parents and teachers have not as yet learnt the very rudiments.” Sense training was fundamental in Comenius’ scheme of primary education. Nature studies—plants, animals, and minerals—were introduced from the first, that the child might early cultivate his powers of observation, and form the habit of acquiring knowledge at first hand. Rousseau likewise lays great stress on sense training. “The faculties which become strong in us,” he says, “are our senses. These, then, are the first that should be cultivated; they are, in fact, the only faculties we forget, or at least those which we neglect most completely. The child wants to touch and handle everything. By no means check this restlessness; it points to a very necessary apprenticeship. Thus it is that the child gets to be conscious of the hotness or coldness, the hardness or softness, the heaviness or lightness of bodies, to judge of their size and shape and all their sensible properties by looking, feeling, listening, especially by comparing sight and touch, and combining the sensations of the eye with those of the fingers.”