History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions.

I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young.

The results of political changes are hardly ever those which their friends hope or their foes fear.

The scientific imagination always restrains itself within the limits of probability.

Every great advance in natural knowledge has involved the absolute rejection of authority.

If a little knowledge is dangerous, where is the man who has so much as to be out of danger?

The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, skepticism is the highest of duties blind faith the one unpardonable sin.

The medieval university looked backwards it professed to be a storehouse of old knowledge. The modern university looks forward, and is a factory of new knowledge.

Try to learn something about everything and everything about something.

Economy does not lie in sparing money, but in spending it wisely.