Wars, therefore, are to be undertaken for this end, that we may live in peace, without being injured; but when we obtain the victory, we must preserve those enemies who behaved without cruelty or inhumanity during the war.
There exists a law, not written down anywhere but inborn in our hearts; a law which comes to us not by training or custom or reading but by derivation and absorption and adoption from nature itself; a law which has come to us not from theory but from practice, not by instruction but by natural intuition. I refer to the law which lays it down that, if our lives are endangered by plots or violence or armed robbers or enemies, any and every method of protecting ourselves is morally right.
Care should be taken that the punishment does not exceed the guilt; and also that some men do not suffer for offenses for which others are not even indicted.
Not to know what has been transacted in former times is to be always a child. If no use is made of the labors of past ages, the world must remain always in the infancy of knowledge.