A vice is a habit of sin. It results from a misuse of man's free will. It will grow out of his evil inclinations if he does not oppose it resolutely by acquiring the opposite virtue.
As virtue is the golden mean, vice is ordinarily found at either extreme of every virtue. There are seven vices, however, which are the source of many others. They are pride, avarice, lust, anger, gluttony, envy, and sloth, and are usually called capital sins.
The majority of mankind are actuated more by instinct and passion in daily life than by reason. They find it difficult to restrain their animal propensities and easily become the slave of avarice, lust, gluttony, intemperance, and sloth. Those on the other hand who try to govern their daily lives according to the dictates of reason find it more difficult to regulate their ambition. They easily permit their inordinate self-love to exaggerate their excellence and puff them up with pride. In consequence they easily become vain and inordinately desirous of the honors of life. Christians can best master their ambition by converting it into zeal for the glory of God and the welfare of souls. They can easily do this, after they are thoroughly converted themselves, by generously promoting the works of zeal and mercy that are established in their community.