As now one and now the other of the elements of a developed legal system has prevailed for the time being, now one and now the other name has come to be used for the whole. The classical period of Roman law was marked by juristic rather than by legislative activity, and the classical period of the modern Roman law was similarly characterized. Hence the preponderance of ius and its equivalents in the languages of Continental Europe. On the other hand, in England, where a strong central authority took the administration of justice in hand under the Normans and through the king’s courts and the king’s writs created a vigorous system which attained fixity before juristic development had gone far enough to exert an influence, law, a word of the second type,8 became the general term, and right,9 never acquired more than an ethical signification.
I have spoken of the traditional element in a legal system as rested upon usage. Thus it is a product of experience. At Rome it grew out of the experience of jurisconsults in answering questions as to actual controversies litigated in the forum. In Anglo-American law it has grown out of decision of cases in the courts and the endeavour to find in recorded judicial experience the principles of deciding new questions arising in concrete experience in concrete controversies. The imperative element, on the contrary, is immediately the work of a lawmaker or lawmaking body. The lawmaker may be advised or guided by a philosopher. But he is likely to think of himself as invested with a power to command. Thus we have law as ascertainment and formulation of just precepts on the basis of experience and law as command of what the lawmaker holds to be just precepts. For judge, jurist, and lawmaker seek to establish just precepts, and each is governed by some ideal.
From the Greek philosophers through the greater part of the history of juristic thought the ideal, both for judge and jurist and for legislator has been provided, in various forms by the theory of natural law, a theory of a body of ideal precepts of universal validity for all peoples, for all times, and for all places, derived from ideas of what an ideal man would do and would not do, would claim and would concede as the claims of others, and arrived at wholly or at least in large part by pure reason.
Civilization, the development of human powers to continually greater completeness, the maximum of human control over external or physical nature and over internal or human nature of which men are for the time being capable, seems to me the starting point for the social sciences. So much, I submit, we can learn from the Neo-Hegelians even if we do not arrive at it nor justify it after the manner of Hegel. It is the control over internal nature which has enabled man to inherit the earth and to maintain and increase that inheritance. The social sciences have to do with this achieved mastery over internal or human nature. They study and teach what it is, how it has come about, and how it is and may be maintained, furthered, and transmitted. Immediately civilization is maintained by social control, by the pressure brought to bear upon each man by his fellow men, the major agencies of which are morals, religion, and law. In the beginnings of law these are not differentiated. Even in so advanced a civilization as the Greek city-state one word is used to mean religious rites, ethical custom, the traditional course of adjusting human relations, the legislative regulations of the city to promote the general security, and all these looked on as a whole. All the agencies of social control and the means of exercising them are included in the one term which we translate as ‘law.’10 The beginnings of philosophical jurisprudence are in Greek philosophical thinking upon social control.
Greek definitions of law vary greatly. Some are imperative,11 some are in terms of agreement, one might say social contract, which would include custom along with legislation,12 some speak of discovery of the natural, universal ethical precept,13 and some of universal rules not only to govern human conduct but governing all things, and so the phenomena of physical nature as well.14 Demosthenes, not a philosopher or jurist, but an orator, i.e., advocate, argued to what may be likened to a jury that they should enforce the law, not run away with it, as both Greek dicasts and Anglo-American jurors will, gave the term almost every meaning that has ever been attributed to it. Law, he said, was something “which men ought to obey for many reasons, and chiefly because every law is both a discovery and a gift of God, and a teaching of wise men and a setting right of wrongs, intended and not intended, but also a common agreement of the state, according to which every one in the state ought to live.”15
But the permanent Greek contribution to juristic thought about law was made by Aristotle. Reflecting on the adjustment of relations and ordering of conduct in the Greek city-state he distinguished two types of precepts in a discussion which became fundamental. He said “Of political justice part is natural, part legal—natural that which everywhere has the same force and does not exist by people’s thinking this or that, legal, that which is originally indifferent, but when it has been laid down is not indifferent, e.g., that a prisoner’s ransom shall be a mina, or that a goat and not two sheep shall be sacrificed, and again all the laws that are passed for particular cases, e.g., that sacrifice shall be made in honor of Brasidas16 and the provisions of decrees.”17
Here Aristotle points out that of the precepts according to which social control was exercised by the politically organized society of a Greek city-state part had the same form everywhere, i.e., in all civilized societies, while part was established by some ruling authority, moral or legal. The text speaks of a natural element, which has the same force everywhere and does not depend on what people think here and there, and an element established by custom of this or that people or community by the local lawmaking authority. The natural is contrasted with the legal or conventional; the universal which had its basis in nature, with the legal or conventional which depended on how men habitually acted in their relations with each other and on how they voted in the lawmaking assemblies or decreed as rulers or as magistrates. This idea of a universal natural law had a strong hold in Greek thought as illustrated in the oft-quoted words which Sophocles puts in the mouth of Antigone: “The unwritten steadfast precepts of the gods.”18 The precept here enjoined upon kinsmen burial of their dead. It was to the Greeks a universal religious precept. The Stoics said that “law was by nature and not by imposition.”19
As to how such precepts were found, the doctrine was not so clear. They might be legal-ethical precepts given to men by the gods, or found by reason, or general religious-ethical or legal-ethical customs, put as ideal universals. Aristotle in another work contrasts the proper law of a particular city-state with the law common to the Greek city-states which is said to be in accord with nature.20 It seems from this text that he thought of ‘common law’ (κοινóς) as ‘natural law’ (νóμóς καταΦύσιν). This suggests a like tendency of Roman jurists to identify ius naturale and ius gentium.
Democritus had said that “rules of law (νóμιμα) are made by men; atoms and void (i.e., the unoccupied space in which the atoms exist) exist by nature.”21 What, then, did the Greek philosophers mean by ‘nature’? Certainly it was not what it meant to the biological evolutionary thinking of the nineteenth century. To the latter the ‘natural’ apple would be the wild crab apple, from which the apple of the