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:

A1 Whether schism is a special sin?

A2 Whether it is graver than unbelief?

A3 Of the power exercised by schismatics;

A4 Of the punishment inflicted on them.