Now in creative thought common sense is a bad master. Its sole criterion for judgement is that the new ideas shall look like the old ones. In other words it can only work by suppressing originality.

Nature, even in the act of satisfying anticipation, often provides a surprise.

Algebra is the intellectual instrument which has been created for rendering clear the quantitative aspects of the world.

Wisdom alone is true ambition's aim, wisdom is the source of virtue and of fame; obtained with labour, for mankind employed, and then, when most you share it, best enjoyed.

Life is complex in its expression, involving more than percipience, namely desire, emotion, will, and feeling.

Identification of rhythm as the casual counterpart of life; wherever there is some life, only perceptible to us when the analogies are sufficiently close.

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.