The moral system of the universe is like a document written in alternate ciphers, which change from line to line.

We must have the real thing before we can have a science of a thing.

No person is ever good for much, that hasn't been swept off their feet by enthusiasm between ages twenty and thirty

Mistakes are often the best teachers.

There are at bottom but two possible religions--that which rises in the moral nature of man, and which takes shape in moral commandments, and that which grows out of the observation of the material energies which operate in the external universe.

Every one of us ... knows better than he practices, and recognizes a better law than he obeys.

The first duty of an historian is to be on his guard against his own sympathies...