Nature does nothing in vain.

We may assume the superiority ceteris paribus of the demonstration which derives from fewer postulates or hypotheses - in short, from fewer premises.

Metaphysics is universal and is exclusively concerned with primary substance. ... And here we will have the science to study that which is, both in its essence and in the properties which it has.

In all well-attempered governments there is nothing which should be more jealously maintained than the spirit of obedience to law, more especially in small matters; for transgression creeps in unperceived and at last ruins the state, just as the constant recurrence of small expenses in time eats up a fortune.

Rising before daylight is also to be commended; it is a healthy habit, and gives more time for the management of the household as well as for liberal studies.

One cannot say of something that it is and that it is not in the same respect at the same time.

Happiness comes from theperfect practice of virtue.