Full Idea
A prince is not able and ought not always to render reasons for the war to its subjects, and if the subjects cannot serve in the war except they be satisfied of its justice, the state would fall into grave peril.
Gist of Idea
Princes should not justify a war to their subjects, and doing so would undermine the state
Source
Francis de Vitoria (On the Law of War [1525], p.176), quoted by Michael Walzer - Just and Unjust Wars 03
Book Reference
Walzer,Michael: 'Just and Unjust Wars' [Penguin 1984], p.39
A Reaction
This medieval view depends entirely on the absolute sovereignty of princes, and confidence that princes are wise and innately just. No student of history should believe such wicked nonsense.