“Freedom of opinion can only exist when the government thinks itself secure.”

In all affairs, it’s a healthy thing now and then to hang a question mark on the things you have long taken for granted.

We know very little, and yet it is astonishing that we know so much, and still more astonishing that so little knowledge can give us so much power.

And if there were a God, I think it very unlikely that he would have such an uneasy vanity as to be offended by those who doubt his existence.

The secret of happiness is to face the fact that the world is horrible, horrible, horrible.

No one gossips about other people’s secret virtues.

The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.

Is there any knowledge in the world that is so certain that no reasonable man could doubt it?

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.

Fear is the parent of cruelty, and therefore it is no wonder if cruelty and religion have gone hand in hand.

It has been said that man is a rational animal. All my life I have been searching for evidence that could support this.

Anything you’re good at contributes to happiness.

We love our habits more than our income, often more than our life.

Sin is geographical.

The good life is inspired by love and guided by knowledge.

Mathematics, rightly viewed, possesses not only truth but supreme beauty – a beauty cold and austere.

Extreme hopes are born from extreme misery.

Nothing exists for itself alone, but only in relation to other forms of life.

Pain, pleasure and death are no more than a process for existence. The revolutionary struggle in this process is a doorway open to intelligence.

Angels on earth exist I know it.

Racism exists, but it is far less rampant than ignorance, and ignorance can be cured through experience.

The past and future are real illusions, that they exist in the present, which is what there is and all there is.

The real question is not whether life exists after death. The real question is whether you are alive before death.

Like love, the light or guidance of truth that influences us exists only in living form, not in principles or rules or expectations or advice, however widely circulated.

We would not dare to conceive the things which are really mere common places of existence.