Cicero: All wars, undertaken without a proper motive, are unjust
From De re publica
Translated by Francis Barham
No war can be undertaken by a just and wise state, unless for faith or self–defence…
All wars, undertaken without a proper motive, are unjust. And no war can be reputed just, unless it be duly announced and proclaimed, and if it be not preceded by a rational demand for restitution.
When Alexander inquired of a pirate by what right he dared to infest the sea with his little brigantine: “By the same right (he replied) which is your warrant for conquering the world.”…This same Alexander, this mighty general, who extended his empire over all Asia, how could he, without violating the property of other men, acquire such universal dominion, enjoy so many pleasures, and reign without bound or limit?
Now if Justice, as you assert, commands us to have mercy upon all; to exercise universal philanthropy; to consult the interests of the whole human race; to give every one his due, and to injure no sacred, public, or foreign rights – how shall we reconcile this vast and all–embracing justice with worldly wisdom and policy, which teach us how to gain wealth, power, riches, honours provinces, and kingdoms from all classes, peoples, and nations?
If we were to examine the conduct of states by the test of justice, as you propose, we should probably make this astounding discovery, that very few nations, if they restored what they have usurped, would possess any country at all, – with the exception, perhaps, of the Arcadians and Athenians, who, I presume, dreading that this great act of retribution might one day arrive, pretend that they were sprung from the earth like so many of our field mice.
There is a true law, a right reason, conformable to nature, universal, unchangeable, eternal, whose commands urge us to duty, and whose prohibitions restrain us from evil. Whether it enjoins or forbids, the good respect its injunctions, and the wicked treat them with indifference. This law cannot be contradicted by any other law, and is not liable either to derogation or abrogation. Neither the senate nor the people can give us any dispensation for not obeying this universal law of justice. It needs no other expositor and interpreter than our own conscience. It is not one thing at Rome and another at Athens; one thing to–day and another to–morrow; but in all times and nations this universal law must for ever reign, eternal and imperishable. It is the sovereign master and emperor of all beings.