Liberty for all their healthful activities and enjoyments prompted and dictated by Nature, this is the fundamental Rousseauean _dictum_. Another collateral principle set up by Rousseau, the full significance of which is only lately beginning to be realized, is that of education by inaction, by delay. He says: “May I venture here to lay down the greatest, most important, and most useful rule of education? It is this, not to gain time, but to lose it.... We should not tamper with the mind till it has acquired all its faculties; for it is impossible it should perceive the light we hold out to it while it is blind.” “Let the infancy of children therefore have time to ripen. In short, whatever instruction is necessary for them, take care not to give it them to-day, if it may be deferred without danger till to-morrow” (17: i, pp. 114-116). Do not imagine that there is no education when we ourselves do not instruct or train a child. “Before he can speak, before he can understand, he is already instructed. Experience is the forerunner of precept” (17: i, p. 57). There is little danger in intrusting a child’s growth to the hand of Nature, and “so long as we know not how to proceed, wisdom consists in remaining inactive” (17: iii, p. 172). Thus he opposes teaching a child a multiplicity of things. Ignorance is better than imbibing superficial knowledge and false ideas. He also rallies the _encyclopedists_ of his day, who were “enamored by the charms of universal knowledge,” and likens them to “a child gathering shells on the seashore. He first loads himself indiscriminately with as many as he can carry; when, tempted by others of a gayer appearance, he throws the first away, taking and rejecting till fatigued and bewildered in his choice, he has thrown all away, and returns home without a single shell” (17: i, p. 270). There are so many things in the world which we all need not or should not know. Ignorance is as much virtue as knowledge. Elimination is probably as necessary for the true advancement of science and humanity as accumulation. But the knowledge he so much depreciates and the ignorance he thus advocates in children refer chiefly to words and books. According to him, the only true knowledge is that direct experience of reality which comes through the exercise of our organs and faculties; it is action that really instructs us. In his opinion: “The multiplicity of books is destructive of science. Imagining the theory we have read in authors to be sufficient, we think ourselves excused from the trouble of learning the practice. Too much reading only encourages presumption and ignorance.... Such a multitude of books makes us forget the volume of the world” (17: iii, pp. 188-189).