What is understood by faction, the sin that is opposed to peace?
By faction is understood strife between individuals without any sanction whatsoever of the public authority; and it is always of itself a grave sin in him who is the author thereof (XLI. 1).
Next - The Catechism of the Summa - SECOND SECTION - A DETAILED SURVEY OF MAN'S RETURN TO GOD - X. OF THE VICES OPPOSED TO CHARITY AND THEIR ACTS: OF HATRED; DISTASTE FOR SPIRITUAL THINGS AND LAZINESS; ENVY; DISCORD; STRIFE; SCHISM; WAR; QUARRELLING (THE DUEL); SEDITION; SCANDAL (J)