Worry is a form of fear.

Science does not aim at establishing immutable truths and eternal dogmas; its aim is to approach the truth by successive approximations, without claiming that at any stage final and complete accuracy has been achieved.

In astronomy, the law of gravitation is plainly better worth knowing than the position of a particular planet on a particular night, or even on every night throughout a year. There are in the law a splendour and simplicity and sense of mastery which illuminate a mass of otherwise uninteresting details. But in history the matter is far otherwise. Historical facts, many of them, have an intrinsic value, a profound interest on their own account, which makes them worthy of study, quite apart from any possibility of linking them together by means of causal laws.

It seems to me a fundamental dishonesty, and a fundamental treachery to intellectual integrity to hold a belief because you think it's useful and not because you think it's true.

If a philosophy is to bring happiness it should be inspired by kindly feelings. Marx pretended that he wanted the happiness of the proletariat; what he really wanted was the unhappiness of the bourgeois.

It appeared that after first contemplating a book on some subject, and after giving serious preliminary attention to it, I needed a period of subconscious incubation which could not be hurried and was if anything impeded by deliberate thinking.... Having, by a time of very intense concentration, planted the problem in my subconsciousness, it would germinate underground until, suddenly, the solution emerged with a blinding clarity, so that it only remained to write down what happened as if in a revelation.

The fundamental defect of fathers, in our competitive society, is that they want their children to be a credit to them.