But if men would give heed to the nature of substance they would doubt less concerning the Proposition that Existence appertains to the nature of substance: rather they would reckon it an axiom above all others, and hold it among common opinions. For then by substance they would understand that which is in itself, and through itself is conceived, or rather that whose knowledge does not depend on the knowledge of any other thing.

He alone is free who lives with free consent under the entire guidance of reason.

The more we understand individual things, the more we understand God.

Measure, time and number are nothing but modes of thought or rather of imagination.

When a man is prey to his emotions, he is not his own master.

Better that right counsels be known to enemies than that the evil secrets of tyrants should be concealed from the citizens. They who can treat secretly of the affairs of a nation have it absolutely under their authority; and as they plot against the enemy in time of war, so do they against the citizens in time of peace.

If you want the present to be different from the past, study the past.