Of Discord, which is Contrary to Peace

We must now consider the sins contrary to peace, and first we shall consider discord which is in the heart, secondly contention, which is on the lips, thirdly, those things which consist in deeds, viz. schism, quarrelling, war, and sedition. Under the first head there are two points of inquiry:

(1) Whether discord is a sin?

(2) Whether it is a daughter of vainglory?