I regret that it has been necessary for me in this lecture to administer a large dose of four-dimensional geometry. I do not apologize, because I am really not responsible for the fact that nature in its most fundamental aspect is four-dimensional. Things are what they are.

The importance of an individual thinker owes something to chance. For it depends upon the fate of his ideas in the minds of his successors.

Education which is not modern share the fate of all organic things which are kept too long.

It is impossible to meditate on time and the mystery of nature without an overwhelming emotion at the limitations of human intelligence.

I consider Christianity to be one of the great disasters of the human race... It would be impossible to imagine anything more un - Christianlike than theology.

We must not expect simple answers to far-reaching questions. However far our gaze penetrates, there are always heights beyond which block our vision.

What we perceive as the present is the vivid fringe of memory tinged with anticipation.