Vanity of science. Knowledge of physical science will not console me for ignorance of morality in time of affliction, but knowledge of morality will always console me for ignorance of physical science.

Thus so wretched is man that he would weary even without any cause for weariness... and so frivolous is he that, though full of a thousand reasons for weariness, the least thing, such as playing billiards or hitting a ball, is sufficient enough to amuse him.

Atheism shows strength of mind, but only to a certain degree.

The strength of a man's virtue should not be measured by his special exertions, but by his habitual acts.

To have no time for philosophy is to be a true philosopher.