Only free men are thoroughly grateful one to another.

The highest activity a human being can attain is learning for understanding, because to understand is to be free.

Everything in nature is a cause from which there flows some effect.

Ceremonies are no aid to blessedness.

In the state of nature, wrong-doing is impossible ; or, if anyone does wrong, it is to himself, not to another.

He who hates anyone will endeavor to do him an injury, unless he fears that a greater injury will thereby accrue to himself; on the other hand, he who loves anyone will, by the same law, seek to benefit him.

Love is nothing but joy accompanied with the idea of an eternal cause.