Whatsoever is contrary to nature is contrary to reason, and whatsoever is contrary to reason is absurd.

True knowledge of good and evil as we possess is merely abstract or general, and the judgment which we pass on the order of things and the connection of causes, with a view to determining what is good or bad for us in the present, is rather imaginary than real.

In the mind there is no absolute or free will; but the mind is determined to wish this or that by a cause, which has also been determined by another cause, and this last by another cause, and so on to infinity.

There is no hope unmingled with fear, and no fear unmingled with hope.

Freedom is self-determination.

Whatever increases, decreases, limits or extends the body's power of action, increases decreases, limits, or extends the mind's power of action. And whatever increases, decreases, limits, or extends the mind's power of action, also increases, decreases, limits, or extends the body's power of action.

Those who wish to seek out the cause of miracles and to understand the things of nature as philosophers, and not to stare at them in astonishment like fools, are soon considered heretical and impious, and proclaimed as such by those whom the mob adores as the interpreters of nature and the gods.