I have become an obstinate heretic in the eyes of my colleagues. Momentary success carries more power of conviction than reflections upon principles.

Not until we dare to regard ourselves as a nation, not until we respect ourselves, can we gain the esteem of others, or rather only then will it come of its own accord

The world we have made is a result of the level of thinking we have done thus far.

What is the meaning of human life, or, for that matter, of the life of any creature? To know the answer to this question means to be religious. You ask: Does it make any sense, then, to pose this question? I answer: The man who regards his fellow creatures as meaningless is not merely unhappy but hardly fit for life.

I am a deeply religious nonbeliever - this is a somewhat new kind of religion.

It is my conviction that pure mathematical construction enables us to discover the concepts and the laws connecting them, which gives us the key to the understanding of nature ... In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.

If you can't explain what you are doing to a nine-year-old, then either you still don't understand it very well, or it's not all that worthwile in the first place.