The brain may be regarded as a kind of parasite of the organism, a pensioner, as it were, who dwells with the body.

Nature shows that with the growth of intelligence comes increased capacity for pain, and it is only with the highest degree of intelligence that suffering reaches its supreme point.

It is the courage to make a clean breast of it in the face of every question that makes the philosopher. He must be like Sophocles' Oedipus, who, seeking enlightenment concerning his terrible fate, pursues his indefatigable inquiry even though he divines that appalling horror awaits him in the answer. But most of us carry with us the Jocasta in our hearts, who begs Oedipus, for God's sake, not to inquire further.

Just as a stream flows smoothly on as long as it encounters no obstruction, so the nature of man and animal is such that we never really notice or become conscious of what is agreeable to our will; if we are to notice something, our will has to have been thwarted, has to have experienced a shock of some kind.

The young should early be trained to bear being left alone; for it is a source of happiness and peace of mind.

Sexual passion is the cause of war and the end of peace, the basis of what is serious... and consequently the concentration of all desire

My body and my will are one.