also has a right to defend his property, though opinions differ as to the amount of injury he may
justly inflict upon a thief.
In the relations between States, as Locke points out, "natural" law is relevant. In what
circumstances is war justified? So long as no international government exists, the answer to this
question is purely ethical, not legal; it must be answered in the same way as it would be for an
individual in a state of anarchy.
Legal theory will be based upon the view that the "rights" of individuals should be protected by
the State. That is to say, when a man suffers the kind of injury which would justify retaliation
according to the principles of natural law, positive law should enact that the retaliation shall be
done by the State. If you see a man making a murderous assault upon your brother, you have a
right to kill him, if you cannot otherwise save your brother. In a state of nature--so, at least, Locke
holds--if a man has succeeded in killing your brother, you have a right to kill him. But where law
exists, you lose this right, which is taken over by the State. And if you kill in self-fence or in
defence of another, you will have to prove to a law-court that this was the reason for the killing.
We may then identify "natural law" with moral rules in so far as they are independent of positive
legal enactments. There must be such rules if there is to be any distinction between good and bad
laws. For Locke, the matter is simple, since moral rules have been laid down by God, and are to be
found in the Bible. When this theological basis is removed, the matter becomes more difficult. But
so long as it is held that there is an ethical distinction between right actions and wrong ones, we
can say: Natural law decides what actions would be ethically right, and what wrong, in a
community that had no government; and positive law ought to be, as far as possible, guided and
inspired by natural law.
In its absolute form, the doctrine that an individual has certain inalienable rights is incompatible
with utilitarianism, i.e., with the doctrine that right acts are those that do most to promote the
general happiness. But in order that a doctrine may be a suitable basis for law, it is not necessary
that it should be true in every possible case, but only that it should be true in an overwhelming
majority of cases. We can all imagine cases in which murder would be justifiable, but they are
rare, and do not afford an argument against the illegality of murder.