The worst guilt is to accept an undeserved guilt — and that is what you have been doing all your life.

America's abundance was created not by public sacrifices to the common good, but by the productive genius of free men who pursued their own personal interests and the making of their own private fortunes. They did not starve the people to pay for America's industrialization. They gave the people better jobs, higher wages, and cheaper goods with every new machine they invented, with every scientific discovery or technological advance- and thus the whole country was moving forward and profiting, not suffering, every step of the way.

Definitions are the guardians of rationality, the first line of defense against the chaos of mental disintegration.

It is too early to feel fear of the future when one is under 30, and too late after that. What I mean is that one must never allow fear to become one's permanent sense of life. The important thing is to prepare yourself intellectually to deal with whatever circumstances you may encounter, which requires that you define your values fully, clearly and rationally -- and never betray them.

Some day, the world will discover that, without thought, there can be no love.

The most depraved type of human being ... (is) the man without a purpose.

I started my life with a single absolute: that the world was mine to shape in the image of my highest values and never to be given up to a lesser standard, no matter how long or hard the struggle.