What is more immoral than war?

The primary and most beautiful of Nature's qualities is motion, which agitates her at all times, but this motion is simply a perpetual consequence of crimes, she conserves it by means of crimes only.

Nature has endowed each of us with a capacity for kindly feelings: let us not squander them on others.

The impossibility of outraging nature is the greatest anguish man can know.

Every principle is a judgment, every judgment the outcome of experience, and experience is only acquired by the exercise of the senses; whence it follows that religious principles bear upon nothing whatever and are not in the slightest innate. Ignorance and fear, you will repeat to them, ignorance and fear - those are the twin bases of every religion.

If Nature denies eternity to beings, it follows that their destruction is one of her laws. Now, once we observe that destruction is so useful to her that she absolutely cannot dispense with it from this moment onward the idea of annihilation which we attach to death ceases to be real what we call the end of the living animal is no longer a true finish, but a simple transformation, a transmutation of matter. According to these irrefutable principles, death is hence no more than a change of form, an imperceptible passage from one existence into another.

The idea of God is the sole wrong for which I cannot forgive mankind.