I’m reading Rousseau’s Emile for the first time. In Book I he discusses the physical constitution of the child and makes myriad recommendations for safeguarding the nature of this constitution. As Dewey will do a couple centuries later, he gives a significant place to habit in education. But he also acknowledges what we might call the pre-habitual plasticity of the child’s constitution: ‘Before the body’s habit is acquired, one can give it the habit one wants to give it without danger. But when it has once gained its consistency, every alteration becomes perilous for it. A child will bear changes that a man would not bear; the fibers of the former, soft and flexible, take without effort the turn that they are given; those of the man, more hardened, change only with violence the turn they have received’ (Bloom trans., 47).
Dewey, it seems to me, is thinking of impulse in the same terms that Rousseau is conceiving the child’s constitution. Beyond this, Rousseau is quite fascinating to read for all of the advice he gives about child-rearing, ranging in theme from air quality to the diet of the child’s nurse (which should be, we learn, a vegetarian one).