1. “From my early youth I have had the strongest desire to understand or explain whatever I observed,—that is, to group all facts under some general laws.” — fromThe Autobiography of Charles Darwin

  2. “John has genius, and so has Charles. Take care that they don’t go astray. Cultivate their minds, inspire their little hearts, raise their wishes. Fix their attention upon great and glorious objects. Root out every little thing. Weed out every meanness. Make them great and manly. Teach them to scorn injustice, ingratitude, cowardice, and falsehood. Let them revere nothing but religion, morality, and liberty.” — from The Familiar Letters of John Adams and His Wife Abigail Adams During the Revolution

  3. “My habits are methodical, and this has been of not a little use for my particular line of work. Lastly, I have had ample leisure from not having to earn my own bread. Even ill-health, though it has annihilated several years of my life, has saved me from the distractions of society and amusement.” — from The Autobiography of Charles Darwin

  4. “I was struck with General Washington. You had prepared me to entertain a favorable opinion of him, but I thought the half was not told me. Dignity with ease and complacency, the gentleman and soldier, look agreeably blended in him. Modesty marks every line and feature of his face. Those lines of Dryden instantly occurred to me:— “Mark his majestic fabric; he’s a temple Sacred by birth, and built by hands divine; His soul’s the deity that lodges there; Nor is the pile unworthy of the god.” — from The Familiar Letters of John Adams and His Wife Abigail Adams During the Revolution

  5. “It should be your care, therefore, and mine, to elevate the minds of our children and exalt their courage; to accelerate and animate their industry and activity; to excite in them an habitual contempt of meanness, abhorrence of injustice and inhumanity, and an ambition to excel in every capacity, faculty, and virtue. If we suffer their minds to grovel and creep in infancy, they will grovel all their lives. But their bodies must be hardened, as well as their souls exalted. Without strength and activity and vigor of body, the brightest mental excellences will be eclipsed and obscured.” — from The Familiar Letters of John Adams and His Wife Abigail Adams During the Revolution

  6. “Therefore my success as a man of science, whatever this may have amounted to, has been determined, as far as I can judge, by complex and diversified mental qualities and conditions. Of these, the most important have been—the love of science—unbounded patience in long reflecting over any subject—industry in observing and collecting facts—and a fair share of invention as well as of common sense. With such moderate abilities as I possess, it is truly surprising that I should have influenced to a considerable extent the belief of scientific men on some important points.” — from The Autobiography of Charles Darwin

  7. “I hope by degrees we shall be inured to hardships, and become a virtuous, valiant people, forgetting our former luxury, and each one apply with industry and frugality to manufactures and husbandry, till we rival all other nations by our virtues.” — from The Familiar Letters of John Adams and His Wife Abigail Adams During the Revolution

  8. “Keep by every means what is your own; do not desire what belongs to others. Fidelity (integrity) is your own, virtuous shame is your own; who then can take these things from you? who else than yourself will hinder you from using them? But how do you act? When you seek what is not your own, you lose that which is your own.” — from The Golden Sayings of Epictetus

  9. “My power to follow a long and purely abstract train of thought is very limited; and therefore I could never have succeeded with metaphysics or mathematics. My memory is extensive, yet hazy: it suffices to make me cautious by vaguely telling me that I have observed or read something opposed to the conclusion which I am drawing, or on the other hand in favour of it; and after a time I can generally recollect where to search for my authority. So poor in one sense is my memory, that I have never been able to remember for more than a few days a single date or a line of poetry.” — from The Autobiography of Charles Darwin

  10. “During another period I smoked excessively, threatening to ruin my health. Then my will asserted itself and I not only stopped, but destroyed all inclination. Long ago I suffered from heart trouble, until I discovered that it was due to the innocent cup of coffee I consumed every morning. I discontinued at once, though I confess it was not an easy task. In this way I checked and bridled other habits and passions, and have not only preserved my life but derived an immense amount of satisfaction from what most men would consider privation and sacrifice.” — from My Inventions by Nikola Tesla