The struggle for existence holds as much in the intellectual as in the physical world. A theory is a species of thinking, and its right to exist is coextensive with its power of resisting extinction by its rivals.
The only medicine for suffering, crime, and all other woes of mankind, is wisdom. Teach a man to read and write, and you have put into his hands the great keys of the wisdom box. But it is quite another thing to open the box.
Logical consequences are the scarecrows of fools and the beacons of wise men.
Time, whose tooth gnaws away everything else, is powerless against truth.
History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions.
It is the customary fate of new truths, to begin as heresies, and to end as superstitions.