We must now consider the vices contrary to peace, which belong to deeds: such are schism, strife, sedition, and war. In the first place, then, about schism, there are four points of inquiry:

(1) Whether schism is a special sin?

(2) Whether it is graver than unbelief?

(3) Of the power exercised by schismatics;

(4) Of the punishment inflicted on them.