The term "passions" refers to the affections or the feelings. By his emotions man intuits the good and suspects evil.
The principal passions are love and hatred, desire and fear, joy, sadness, and anger.
In the passions, as movements of the sensitive appetite, there is neither moral good nor evil. But insofar as they engage reason and will, there is moral good or evil in them.
Emotions and feelings can be taken up in the virtues or perverted by the vices.
The perfection of the moral good consists in man's being moved to the good not only by his will but also by his "heart."