I should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall, therefore, treat the nature and strength of the emotion in exactly the same manner, as though I were concerned with lines, planes, and solids.

I do not know how to teach philosophy without becoming a disturber of the peace.

Sein, was wir sind, und werden, was wir werden können, das ist das Ziel des Lebens.

These are the prejudices which I undertook to notice here. If any others of a similar character remain, they can easily be rectified with a little thought by anyone.

The superstitious know how to reproach people for their vices better than they know how to teach them virtues, and they strive, not to guide men by reason, but to restrain them by fear, so that they flee the evil rather than love virtues. Such people aim only to make others as wretched as they themselves are, so it is no wonder that they are generally burdensome and hateful to men.

The good which every man, who follows after virtue, desires for himself he will also desire for other men...