Everything great is just as difficult to realize as it is rare to find.

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.

[Believers] are but triflers who, when they cannot explain a thing, run back to the will of God; this is, truly, a ridiculous way of expressing ignorance.

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.

self-preservation is the primary and only foundation of virtue.

Laws which prescribe what everyone must believe, and forbid men to say or write anything against this or that opinion, are often passed to gratify, or rather to appease the anger of those who cannot abide independent minds.

Will and intellect are one and the same thing.