“I always believe in going hard at everything, whether it is Latin or mathematics, boxing or football, but at the same time I want to keep the sense of proportion. It is never worth while to absolutely exhaust one’s self or to take big chances unless for an adequate object. I want you to keep in training the faculties which would make you, if the need arose, able to put your last ounce of pluck and strength into a contest. But I do not want you to squander these qualities.”

Theodore Roosevelt, Theodore Roosevelt’s Letters to His Children (1919)

“There is no need to be a prig. There is no need for a boy to preach about his own good conduct and virtue. If he does he will make himself offensive and ridiculous. But there is urgent need that he should practise decency; that he should be clean and straight, honest and truthful, gentle and tender, as well as brave. If he can once get to a proper understanding of things, he will have a far more hearty contempt for the boy who has begun a course of feeble dissipation, or who is untruthful, or mean, or dishonest, or cruel, than this boy and his fellows can possibly, in return, feel for him.”

Theodore Roosevelt, The Strenuous Life (1900)