There cannot, I conceive, be any question that to the assumption of a Law Natural we owe the doctrine of the fundamental equality of human beings. That ‘all men are equal’ is one of a large number of legal propositions which, in progress of time, have become political.
The Roman jurisconsults of the Antonine era lay down that ‘omnes homines naturâ æquales sunt,’ but in their eyes this is a strictly juridical axiom. They intend to affirm that, under the hypothetical Law of Nature, and in so far as positive law approximates to it, the arbitrary distinctions which the Roman Civil Law maintained between classes of persons cease to have a legal existence. The rule was one of considerable importance to the Roman practitioner, who required to be reminded that, wherever Roman jurisprudence was assumed to conform itself exactly to the code of Nature, there was no difference in the contemplation of the Roman tribunals between citizen and foreigner, between freeman and slave, between Agnate and Cognate. The jurisconsults who thus expressed themselves most certainly never intended to censure the social arrangements under which civil law fell somewhat short of its speculative type; nor did they apparently believe that the world would ever see human society completely assimilated to the economy of nature. But when the doctrine of human equality makes its appearance in a modern dress it has evidently clothed itself with a new shade of meaning. Where the Roman jurisconsult had written ‘æquales sunt,’ meaning exactly what he said, the modern civilian wrote ‘all men are equal’ in the sense of ‘all men ought to be equal.’ The peculiar Roman idea that natural law coexisted with civil law and gradually absorbed it, had evidently been lost sight of, or had become unintelligible, and the words which had at most conveyed a theory concerning the origin, composition, and development of human institutions, were beginning to express the sense of a great standing wrong suffered by mankind. As early as the beginning of the fourteenth century, the current language concerning the birth-state of men, though visibly intended to be identical with that of Ulpian and his contemporaries, has assumed an altogether different form and meaning. The preamble to the celebrated ordinance of King Louis Hutin enfranchising the serfs of the royal domains would have sounded strangely to Roman ears. ‘Whereas, according to natural law, everybody ought to be born free; and by some usages and customs which, from long antiquity, have been introduced and kept until now in our realm, and peradventure by reason of the misdeeds of their predecessors, many persons of our common people have fallen into servitude, therefore, We, etc.’ This is the enunciation not of a legal rule but of a political dogma; and from this time the equality of men is spoken of by the French lawyers just as if it were a political truth which happened to have been preserved among the archives of their science. Like all other deductions from the hypothesis of a Law Natural, and like the belief itself in a Law of Nature, it was languidly assented to and suffered to have little influence on opinion and practice until it passed out of the possession of the lawyers into that of the literary men of the eighteenth century and of the public which sat at their feet. With them it became the most distinct tenet of their creed, and was even regarded as a summary of all the others. It is probable, however, that the power which it ultimately acquired over the events of 1789 was not entirely owing to its popularity in France, for in the middle of the century it passed over to America. The American lawyers of the time, and particularly those of Virginia, appear to have possessed a stock of knowledge which differed chiefly from that of their English contemporaries in including much which could only have been derived from the legal literature of continental Europe. A very few glances at the writings of Jefferson will show how strongly his mind was affected by the semi-juridical, semi-popular opinions which were fashionable in France, and we cannot doubt that it was sympathy with the peculiar ideas of the French jurists which led him and the other colonial lawyers who guided the course of events in America to join the specially French assumption that ‘all men are born equal’ with the assumption, more familiar to Englishmen, that ‘all men are born free,’ in the very first lines of their Declaration of Independence. The passage was one of great importance to the history of the doctrine before us. The American lawyers, in thus prominently and emphatically affirming the fundamental equality of human beings, gave an impulse to political movements in their own country, and in a less degree in Great Britain, which is far from having yet spent itself; but besides this they returned the dogma they had adopted to its home in France, endowed with vastly greater energy and enjoying much greater claims on general reception and respect. Even the more cautious politicians of the first Constituent Assembly repeated Ulpian’s proposition as if it at once commended itself to the instincts and intuitions of mankind; and of all the ‘principles of 1789’ it is the one which has been least strenuously assailed, which has most thoroughly leavened modern opinion, and which promises to modify most deeply the constitution of societies and the politics of states.
Sir Henry Sumner Maine, Ancient Law: Its Connection to the History of Early Society (1861), ch. 4, “The Modern History of the Law of Nature.”