To come very near to a true theory, and to grasp its precise application, are two different things, as the history of science teaches us. Everything of importance has been said before by someone who did not discover it.

Great people plant trees they'll never sit under.

The merely well-informed man is the most useless bore on God's earth.

Learning preserves the errors of the past as well as its wisdom.

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.

In this modern world, the celibacy of the medieval learned class has been replaced by a celibacy of the intellect which is divorced from the concrete contemplation of the complete facts.

The point about zero is that we do not need to use it in the operations of daily life. No one goes out to buy zero fish. It is in a way the most civilised of all the cardinals, and its use is only forced on us by the needs of cultivated modes of thought.