more from Thomas Aquinas

Single Idea 7291

[catalogued under 25. Social Practice / E. Policies / 1. War / a. Just wars]

Full Idea

Aquinas argued that on three conditions war can be justified: first, that there is a just cause; second, that it is begun on proper authority; and third, that it is waged with right intention, for 'the advancement of good, or the avoidance of evil'.

Gist of Idea

For Aquinas a war must be in a just cause, have proper authority, and aim at good


report of Thomas Aquinas (Summa Theologicae [1265], II) by A.C. Grayling - Among the Dead Cities Ch.6

Book Reference

Grayling,A.C.: 'Among the Dead Cities' [Bloomsbury 2006], p.211

A Reaction

But see also Idea 7292. Nowadays we are rightly suspicious of all three conditions. Evil people seem to think their cause is just; authority has often been seized by violence, or is being abused; and people seem confused about what is good or evil.

Related Idea

Idea 7292 War must also have a good chance of success, and be waged with moderation [Grayling]