The knowledge of God is the cause of things. For the knowledge of God is to all creatures what the knowledge of the artificer is to things made by his art.

If all the sins of the flesh are worthy of condemnation because by them man allows himself to be dominated by that which he has of the animal nature, much more deserving of condemnation are the sins against nature by which man degrades his own animal nature.

The soul is perfected by knowledge and virtue.

It is a sin directly against one's neighbour, since one man cannot over-abound in external riches, without another man lacking them.

For it is necessary in every practical science to proceed in a composite (i.e. deductive) manner. On the contrary in speculative science, it is necessary to proceed in an analytical manner by breaking down the complex into elementary principles.

To live well is to work well, to show a good activity.

Charity is the form, mover, mother and root of all the virtues.