Because of the diverse conditions of humans, it happens that some acts are virtuous to some people, as appropriate and suitable to them, while the same acts are immoral for others, as inappropriate to them.

A person is disposed to an act of choice by an angel ... in two ways. Sometimes, a man's understanding is enlightened by an angel to know what is good, but it is not instructed as to the reason why ... But sometimes he is instructed by angelic illumination, both that this act is good and as to the reason why it is good.

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.

I would rather feel compassion than know the meaning of it. I would hope to act with compassion without thinking of personal gain.

Clearly the person who accepts the Church as an infallible guide will believe whatever the Church teaches.

Man can sin against nature in two ways. First, when he sins against his specific rational nature, acting contrary to reason. In this sense, we can say that every sin is a sin against man's nature, because it is against man's right reason.

Love is a binding force, by which another is joined to me and cherished by myself.