This capricious arbitrary aspect of law was a thing which much impressed the Greeks. They contrasted the varying, artificial arrangements made by mankind with the constancy and simplicity of nature. We speak of nature and convention; they contrasted things that are by nature with things that are by law. It was a contrast that bore fruit later on. Now law, whose arbitrariness and variety so much impressed the Greeks was the law not so much of this place or that, as of this or that community and its members. This is a conception quite different from that of the modern world. We may paraphrase 'English law' by saying the law of England, because it is the law which will be applied (with, it may be, some exceptions or modifications) by the English courts to all persons, be they English or aliens, who come before them. But Athenian law is not in this sense the law of Athens, nor, to begin with, is Roman law the law of Rome. What we find is a law of Athenian or Roman citizens. The stranger to the city is a stranger to its law. As a matter of principle he is without rights by that law. His life is not protected by the blood-feud which his family can pursue, or by the compensation with which it may be bought off. His marriage with a citizen will be no marriage, or at best a sort of half marriage. He can acquire no land within the city's territory, and what goods he brings with him are pretty much at the mercy of the first taker. Such, at any rate, is the theory of the 'law of citizens'. We need not, it is true, believe that it was logically formulated in primitive times and ruthlessly applied. Some of its applications were the result of positive legislation due to a growing consciousness of the self-sufficiency of the city state and of the privileges of citizenship, as when Athens passed a law excluding from citizenship the offspring of citizens who had married foreign wives. But in its broad outlines the principle is sufficiently borne out by the exceptions which were necessary to make human intercourse possible. The stranger within your gates is protected just because he is within your gates, and you throw your protection about him, as is indeed your duty, for suppliants and strangers come from Zeus. The foreigner, even at a distance, may have a citizen as representative who can and will defend his rights. A stranger may be allowed to take up a permanent residence in the city, and by the mediation of a patron or guardian enjoy private rights not much inferior to those of a citizen. His legal position will not be very different from that of a woman citizen, who needs the like mediation. Cities may, again, by treaty confer on each other's citizens reciprocal rights of legal protection.