But when we devote to the making of these instruments the skill which did instead of them, when for their construction we use the intelligence which enabled us to dispense with them, this is gain not loss, we add art to nature, we gain ingenuity without loss of skill.  If instead of making a child stick to his books I employ him in a workshop, his hands work for the development of his mind.  While he fancies himself a workman he is becoming a philosopher.  Moreover, this exercise has other advantages of which I shall speak later; and you will see how, through philosophy in sport, one may rise to the real duties of man.

I have said already that purely theoretical science is hardly suitable for children, even for children approaching adolescence; but without going far into theoretical physics, take care that all their experiments are connected together by some chain of reasoning, so that they may follow an orderly sequence in the mind, and may be recalled at need; for it is very difficult to remember isolated facts or arguments, when there is no cue for their recall.

In your inquiry into the laws of nature always begin with the commonest and most conspicuous phenomena, and train your scholar not to accept these phenomena as causes but as facts.  I take a stone and pretend to place it in the air; I open my hand, the stone falls.  I see Emile watching my action and I say, “Why does this stone fall?”

What child will hesitate over this question?  None, not even Emile, unless I have taken great pains to teach him not to answer.  Every one will say, “The stone falls because it is heavy.”  “And what do you mean by heavy?” “That which falls.”  “So the stone falls because it falls?” Here is a poser for my little philosopher.  This is his first lesson in systematic physics, and whether he learns physics or no it is a good lesson in common-sense.

As the child develops in intelligence other important considerations require us to be still more careful in our choice of his occupations.  As soon as he has sufficient self-knowledge to understand what constitutes his well-being, as soon as he can grasp such far-reaching relations as to judge what is good for him and what is not, then he is able to discern the difference between work and play, and to consider the latter merely as relaxation.  The objects of real utility may be introduced into his studies and may lead him to more prolonged attention than he gave to his games.  The ever-recurring law of necessity soon teaches a man to do what he does not like, so as to avert evils which he would dislike still more.  Such is the use of foresight, and this foresight, well or ill used, is the source of all the wisdom or the wretchedness of mankind.

Every one desires happiness, but to secure it he must know what happiness is.  For the natural man happiness is as simple as his life; it consists in the absence of pain; health, freedom, the necessaries of life are its elements.  The happiness of the moral man is another matter, but it does not concern us at present.  I cannot repeat too often that it is only objects which can be perceived by the senses which can have any interest for children, especially children whose vanity has not been stimulated nor their minds corrupted by social conventions.