Judging from Appearances. The Broken Stick.
If I have thus far made myself understood, you may see how, with regular physical exercise and manual labor, I am at the same time giving my pupil a taste for reflection and meditation. This will counterbalance the indolence which might result from his indifference to other men and from the dormant state of his passions. He must work like a peasant and think like a philosopher, or he will be as idle as a savage. The great secret of education is to make physical and mental exercises serve as relaxation for each other. At first our pupil had nothing but sensations, and now he has ideas. Then he only perceived, but now he judges. For from comparison of many successive or simultaneous sensations, with the judgments based on them, arises a kind of mixed or complex sensation which I call an idea.
The different manner in which ideas are formed gives each mind its peculiar character. A mind is solid if it shape its ideas according to the true relations of things; superficial, if content with their apparent relations; accurate, if it behold things as they really are; unsound, if it understand them incorrectly; disordered, if it fabricate imaginary relations, neither apparent nor real; imbecile, if it do not compare ideas at all. Greater or less mental power in different men consists in their greater or less readiness in comparing ideas and discovering their relations.
From simple as well as complex sensations, we form judgments which I will call simple ideas. In a sensation the judgment is wholly passive, only affirming that we feel what we feel. In a preception or idea, the judgment is active; it brings together, compares, and determines relations not determined by the senses. This is the only point of difference, but it is important. Nature never deceives us; it is always we who deceive ourselves.
I see a child eight years old helped to some frozen custard. Without knowing what it is, he puts a spoonful in his mouth, and feeling the cold sensation, exclaims, "Ah, that burns!" He feels a keen sensation; he knows of none more so than heat, and thinks that is what he now feels. He is of course mistaken; the chill is painful, but does not burn him; and the two sensations are not alike, since, after encountering both, we never mistake one for the other. It is not, therefore, the sensation which misleads him, but the judgment based on it.
It is the same when any one sees for the first time a mirror or optical apparatus; or enters a deep cellar in mid-winter or midsummer; or plunges his hand, either very warm or very cold, into tepid water; or rolls a little ball between two of his fingers held crosswise. If he is satisfied with describing what he perceives or feels, keeping his judgment in abeyance, he cannot be mistaken. But when he decides upon appearances, his judgment is active; it compares, and infers relations it does not perceive; and it may then be mistaken. He will need experience to prevent or correct such mistakes. Show your pupil clouds passing over the moon at night, and he will think that the moon is moving in an opposite direction, and that the clouds are at rest. He will the more readily infer that this is the case, because he usually sees small objects, not large ones, in motion, and because the clouds seem to him larger than the moon, of whose distance he has no idea. When from a moving boat he sees the shore at a little distance, he makes the contrary mistake of thinking that the earth moves. For, unconscious of his own motion, the boat, the water, and the entire horizon seem to him one immovable whole of which the moving shore is only one part.
The first time a child sees a stick half immersed in water, it seems to be broken. The sensation is a true one, and would be, even if we did not know the reason for this appearance. If therefore you ask him what he sees, he answers truly, "A broken stick," because he is fully conscious of the sensation of a broken stick. But when, deceived by his judgment, he goes farther, and after saying that he sees a broken stick, he says again that the stick really is broken, he says what is not true; and why? Because his judgment becomes active; he decides no longer from observation, but from inference, when he declares as a fact what he does not actually perceive; namely, that touch would confirm the judgment based upon sight alone.
The best way of learning to judge correctly is the one which tends to simplify our experience, and enables us to make no mistakes even when we dispense with experience altogether. It follows from this that after having long verified the testimony of one sense by that of another, we must further learn to verify the testimony of each sense by itself without appeal to any other. Then each sensation at once becomes an idea, and an idea in accordance with the truth. With such acquisitions I have endeavored to store this third period of human life.
To follow this plan requires a patience and a circumspection of which few teachers are capable, and without which a pupil will never learn to judge correctly. For example: if, when he is misled by the appearance of a broken stick, you endeavor to show him his mistake by taking the stick quickly out of the water, you may perhaps undeceive him, but what will you teach him? Nothing he might not have learned for himself. You ought not thus to teach him one detached truth, instead of showing him how he may always discover for himself any truth. If you really mean to teach him, do not at once undeceive him. Let Émile and myself serve you for example.
In the first place, any child educated in the ordinary way would, to the second of the two questions above mentioned, answer, "Of course the stick is broken." I doubt whether Émile would give this answer. Seeing no need of being learned or of appearing learned, he never judges hastily, but only from evidence. Knowing how easily appearances deceive us, as in the case of perspective, he is far from finding the evidence in the present case sufficient. Besides, knowing from experience that my most trivial question always has an object which he does not at once discover, he is not in the habit of giving heedless answers. On the contrary, he is on his guard and attentive; he looks into the matter very carefully before replying. He never gives me an answer with which he is not himself satisfied, and he is not easily satisfied. Moreover, he and I do not pride ourselves on knowing facts exactly, but only on making few mistakes. We should be much more disconcerted if we found ourselves satisfied with an insufficient reason than if we had discovered none at all. The confession, "I do not know," suits us both so well, and we repeat it so often, that it costs neither of us anything. But whether for this once he is careless, or avoids the difficulty by a convenient "I do not know," my answer is the same: "Let us see; let us find out."
The stick, half-way in the water, is fixed in a vertical position. To find out whether it is broken, as it appears to be, how much we must do before we take it out of the water, or even touch it! First, we go entirely round it, and observe that the fracture goes around with us. It is our eye alone, then, that changes it; and a glance cannot move things from place to place.
Secondly, we look directly down the stick, from the end outside of the water; then the stick is no longer bent, because the end next our eye exactly hides the other end from us. Has our eye straightened the stick?
Thirdly, we stir the surface of the water, and see the stick bend itself into several curves, move in a zig-zag direction, and follow the undulations of the water. Has the motion we gave the water been enough thus to break, to soften, and to melt the stick?
Fourth, we draw off the water and see the stick straighten itself as fast as the water is lowered. Is not this more than enough to illustrate the fact and to find out the refraction? It is not then true that the eye deceives us, since by its aid alone we can correct the mistakes we ascribe to it.
Suppose the child so dull as not to understand the result of these experiments. Then we must call touch to the aid of sight. Instead of taking the stick out of the water, leave it there, and let him pass his hand from one end of it to the other. He will feel no angle; the stick, therefore, is not broken.
You will tell me that these are not only judgments but formal reasonings. True; but do you not see that, as soon as the mind has attained to ideas, all judgment is reasoning? The consciousness of any sensation is a proposition, a judgment. As soon, therefore, as we compare one sensation with another, we reason. The art of judging and the art of reasoning are precisely the same.
If, from the lesson of this stick, Émile does not understand the idea of refraction, he will never understand it at all. He shall never dissect insects, or count the spots on the sun; he shall not even know what a microscope or a telescope is.
Your learned pupils will laugh at his ignorance, and will not be very far wrong. For before he uses these instruments, I intend he shall invent them; and you may well suppose that this will not be soon done.
This shall be the spirit of all my methods of teaching during this period. If the child rolls a bullet between two crossed fingers, I will not let him look at it till he is otherwise convinced that there is only one bullet there.