Whenever anyone accuses some person of being 'unfeeling,' he means that that person is just. He means that that person has no causeless emotions and will not grant him a feeling which he does not deserve. He means that 'to feel' is to go against reason, against moral values, against reality.

Do not let your fire go out.

[What for] was the first question he asked about any activity proposed to him - and nothing would make him act, if he found no valid answer. He flew through the days of his summer month like a rocket, but if one stopped him in mid-flight, he could always name the purpose of his every random moment. Two things were impossible to him: to stand still or to move aimlessly.

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.

If you write a whole line of zeroes, it's still — nothing.

Words are a lens to focus one's mind.

In all proper relationships there is no sacrifice of anyone to anyone. An architect needs clients, but he does not subordinate his work to their wishes. They need him, but they do not order a house just to give him commission. Men exchange their work by free, mutual consent to mutual advantage when their personal interests agree and they both desire the exchange.