Now the Law of Nature is so unalterable, that it cannot be changed even by God himself. For although the power of God is infinite, yet there are some things, to which it does not extend. Because the things so expressed would have no true meaning, but imply a contradiction. Thus two and two must make four, nor is it possible to be otherwise; nor, again, can what is really evil not be evil. And this is Aristotle's meaning, when he says, that some things are no sooner named, than we discover their evil nature. For as the substance of things in their nature and existence depends upon nothing but themselves; so there are qualities inseparably connected with their being and essence. Of this kind is the evil of certain actions, compared with the nature of a reasonable being. Therefore God himself suffers his actions to be judged by this rule, as may be seen in the xviiith chap. of Gen. 25. Isa. v. 3. Ezek. xviii. 25. Jer. ii. 9. Mich. vi. 2. Rom. ii. 6., iii. 6. Yet it sometimes happens that, in those cases, which are decided by the law of nature, the undiscerning are imposed upon by an appearance of change. Whereas in reality there is no change in the unalterable law of nature, but only in the things appointed by it, and which are liable to variation. For example, if a creditor forgive me the debt, which I owe him, I am no longer bound to pay it, not because the law of nature has ceased to command the payment of a just debt, but because my debt, by a release, has ceased to be a debt. On this topic, Arrian in Epictetus argues rightly, that the borrowing of money is not the only requisite to make a debt, but there must be the additional circumstance of the loan remaining undischarged. Thus if God should command the life, or property of any one to be taken away, the act would not authorise murder or robbery, words which always include a crime. But that cannot be murder or robbery, which is done by the express command of Him, who is the sovereign Lord of our lives and of all things. There are also some things allowed by the law of nature, not absolutely, but according to a certain state of affairs. Thus, by the law of nature, before property was introduced, every one had a right to the use of whatever he found unoccupied; and, before laws were enacted, to avenge his personal injuries by force. XI. The distinction found in the books of the Roman Law, assigning one unchangeable right to brutes in common with man, which in a more limited sense they call the law of nature, and appropriating another to men, which they frequently call the Law of Nations, is scarcely of any real use. For no beings, except those that can form general maxims, are capable of possessing a right, which Hesiod has placed in a clear point of view, observing "that the supreme Being has appointed laws for men; but permitted wild beasts, fishes, and birds to devour each other for food." For they have nothing like justice, the best gift, bestowed upon men.