A simple and independent mind does not toil at the bidding of any prince.

He is not a true man of science who does not bring some sympathy to his studies, and expect to learn something by behavior as well as by application. It is childish to rest in the discovery of mere coincidences, or of partial and extraneous laws. The study of geometry is a petty and idle exercise of the mind, if it is applied to no larger system than the starry one. Mathematics should be mixed not only with physics but with ethics; that is mixed mathematics. The fact which interests us most is the life of the naturalist. The purest science is still biographical.

After all, the practical reason why, when the power is once in the hands of the people, a majority are permitted, and for a long period continue, to rule is not because they are most likely to be in the right, nor because this seems fairest to the minority, but because they are physically the strongest. But a government in which the majority rule in all cases cannot be based on justice, even as far as men understand it.

Friends will not only live in harmony, but in melody.

All health and success does me good, however far off and withdrawn it may appear; all disease and failure helps to make me sad anddoes me evil, however much sympathy it may have with me or I with it.

Give me the poverty that enjoys true wealth.

Genius is not a retainer to any emperor.