The soul, which is the first principle of life, is not a body, but the act of a body; just as heat, which is the principle of calefaction, is not a body, but an act of a body.

The Study of philosophy is not that we may know what men have thought, but what the truth of things is.

Eternity is called whole, not because it has parts, but because it is lacking in nothing.

To restore man, who had been laid low by sin, to the heights of divine glory, the Word of the eternal Father, though containing all things within His immensity, willed to become small. This He did not by putting aside His greatness but by taking to Himself our littleness.

Wonder [admiratio astonishment, marvel] is a kind of desire for knowledge. The situation arises when one sees an effect and does not know its cause, or when the cause of the particular effect is one that exceeds his power of understanding. Hence, wonder is a cause of pleasure insofar as there is annexed the hope of attaining understanding of that which one wants to know. ... For desire is especially aroused by the awareness of ignorance, and consequently a man takes the greatest pleasure in those things which he discovers for himself or learns from the ground up.

The greatest kindness one can render to any man consists in leading him from error to truth.

A man has free choice to the extent that he is rational.