The knowledge of the world is only to be acquired in the world, and not in a closet.

Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and unbearable pity for the suffering of mankind.

He who has so little knowledge of human natures as to seek happiness by changing anything but his own disposition will waste his life in fruitless efforts.

They [the Americans] have all a lively faith in the perfectibility of man, they judge that the diffusion of knowledge must necessarily be advantageous, and the consequences of ignorance fatal; they all consider society as a body in a state of improvement, humanity as a changing scene, in which nothing is, or ought to be, permanent; and they admit that what appears to them today to be good, may be superseded by something better tomorrow.

A primary object should be the education of our youth in the science of government. In a republic, what species of knowledge can be equally important? And what duty more pressing than communicating it to those who are to be the future guardians of the liberties of the country.

No one can draw more out of things, books included, than he already knows. A man has no ears for that to which experience has given him no access.

Opinion is the medium between knowledge and ignorance.

I keep six honest serving men (they taught me all I knew); Their names are What and Why and When And How and Where and Who.

The best people possess a feeling for beauty, the courage to take risks, the discipline to tell the truth, the capacity for sacrifice. Ironically, their virtues make them vulnerable; they are often wounded, sometimes destroyed.

Be brave. Take risks. Nothing can substitute experience.

I dream, I test my dreams against my beliefs, I dare to take risks, and I execute my vision to make those dreams come true.

If things seem under control, you are just not going fast enough.

There are risks and costs to a program of action. But they are far less than the long range risks and costs of comfortable inaction.

The use of traveling is to regulate imagination by reality, and instead of thinking how things may be, to see them as they are.

If you want to succeed you should strike out on new paths, rather than travel the worn paths of accepted success.