This interval in which the strength of the individual is in excess of his wants is, as I have said… — Jean Jacques Rousseau

This interval in which the strength of the individual is in excess of his wants is, as I have said, relatively though not absolutely the time of greatest strength. It is the most precious time in his life; it comes but once; it is very short, all too short, as you will see when you consider the importance of using it aright.

This is the time for work, instruction, and inquiry. And note that this is no arbitrary choice of mine, it is the way of nature herself. Human intelligence is finite, and not only can no man know everything, he cannot even acquire all the scanty knowledge of others. Since the contrary of every false proposition is a truth, there are as many truths as falsehoods. We must, therefore, choose what to teach as well as when to teach it. Some of the information within our reach is false, some is useless, some merely serves to puff up its possessor. The small store which really contributes to our welfare alone deserves the study of a wise man, and therefore of a child whom one would have wise. He must know not merely what is, but what is useful.

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