Mathematics as a science, commenced when first someone, probably a Greek, proved propositions about "any" things or about "some" things, without specifications of definite particular things.

Great people plant trees they'll never sit under.

Error is the price we pay for progress.

...the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge.

After you understand about the sun and the stars and the rotation of the earth, you may still miss the radiance of the sunset.

The real history does not get written, because it is not in people's brains but in their nerves and vitals.

If you have had your attention directed to the novelties in thought in your own lifetime, you will have observed that almost all really new ideas have a certain aspect of foolishness when they are first produced, and almost any idea which jogs you out of your current abstractions may be better than nothing.