The greatest victory is over self.

Leisure of itself gives pleasure and happiness and enjoyment of life, which are experienced, not by the busy man, but by those who have leisure.

A friend is simply one soul in two bodies.

The life of theoretical philosophy is the best and happiest a man can lead. Few men are capable of it and then only intermittently. For the rest there is a second-best way of life, that of moral virtue and practical wisdom.

Plato is dear to me, but dearer still is truth.

...The entire preoccupation of the physicist is with things that contain within themselves a principle of movement and rest.

When couples have children in excess, let abortion be procured before sense and life have begun; what may or may not be lawfully done in these cases depends on the question of life and sensation.