By contrasting, in the light of their social criticism, what is naturally right with what is legally right, the Sophists attained at this early date to the notion of the rights of man and to the idea of mankind. The unwritten laws, said Hippias, are eternal and unalterable: they spring from a higher source than the decrees of men. To Hippias’ way of thinking, all men are by nature relatives and fellow citizens, even if they are not such in the eyes of the law. Therewith the distinction between Greeks and barbarians, fundamental for Greek cultural consciousness, vanished into thin air. “God made all men free; nature has made no man a slave” (Alcidamas). The whole ethical and legal foundation was thereby taken away from slavery, which was in turn the very basis of the Greek social and economic system. Nevertheless Plato held fast to the institution of slavery, and Aristotle was ever striving to justify it by means of his theory that certain men are slaves by nature.
Three ideas, heavily charged with social explosives for the world of Greek culture, were thus put forward by the Sophists as part and parcel of the natural law. These ideas were thenceforth to be subjected to a ceaseless reprocessing in the history of the mind. Time and again they were to serve revolutionary thinkers as molds and vessels into which these could pour their revolutionary emotions, their schemes for reform, and their political aims. The first idea was that the existing laws serve class interests and are artificial constructions. Only what is naturally moral and naturally right can be properly called moral and right. Next came the idea of the natural-law freedom and equality of all human beings and, as a consequence, the idea of the rights of man as well as the idea of mankind, the civitas maxima, or world community, which is superior to the city-state. According to the third idea, the state, or polis, is nonessential: it owes its origin to a human decision, i.e., to a free contract, not to a necessity of some kind. The political organization of man must therefore have been preceded by a state of nature (portrayed optimistically or pessimistically), in which the pure natural law was in force. According to the optimistic view of the state of nature, this law can in its essential contents be neither altered not abrogated by the state; in the pessimistic view, which leads to positivism, it is merged in the will of the state. But after the lofty flight of speculation had been exposed to the needed self-criticism, the successors of the Sophists fell quickly into skepticism and into a sheer positivism when the underlying optimistic outlook ran afoul of the facts. This was, for instance, the case with the Epicureans, who were the first legal positivists.
The Sophists’ criticism of the positive laws, together with the rapidly growing prominence of the notion of utility, led Epicurus, whose sensistic epistemology left no room for metaphysics, to doubt that anything can be objectively and naturally right. Utility and pleasure became for him the sole principles of ethics and law. But since the resultant subjectivism must endanger the social order and with it the peaceful enjoyment of pleasure, he inferred from the principle of utility that justice as such is a chimera, that it rather exists only in agreements which have been entered into for the prevention of mutual injuries. Justice thus consists entirely in positive laws. Before men entered into agreements and before there were laws founded upon such agreements, men had lived in a haphazard manner, like wild beasts, lawlessly. The state of nature, upon which the Sophists had placed an optimistic construction but which they had not particularly stressed, was thus interpreted in a pessimistic sense in Epicurean circles. From this, however, sprang also the respect of the Epicureans for the existing laws as well as their emphasis upon the value of the legal notions and customary law of individual peoples. The parallelism between the Sophist and Epicurean doctrine on the one hand and, on the other, the natural-law schools of modern times is quite unmistakable. Rousseau, Hobbes, Pufendorf, Thomasius, and the adherents of historical schools of law, who variously combine the elements of individual systems, merely repeat and develop these ancient ideas.
The starting point of the Sophists was a criticism of the nomoi of the Athenian democracy. In their role and guise of popular philosophers and in their political and skeptical snobbery they frequently defended the opposite theories. As if the revolutionary criticism of the nomoi in behalf of slaves and non-citizens, considered barbarians, and the conservative utilitarianism of Epicurus were not sufficiently unsettling, Callicles, if we are to trust tradition, stood forth as champion of the doctrine of the right of the stronger, i.e., that might makes right. A pure materialist in his philosophy, Callicles reached the conclusion that law, such as obtained in the Athenian democracy, was in reality injustice. For, he contended, the many who are weak have united to fetter with the bands of law the few who are strong. But nature teaches, as a glance at the animal kingdom and at warring states reveals, that the stronger naturally overcomes the weaker. Natural law, then, is the force of the stronger. For this snobbish leader of the oligarchic faction such was the way one could and should get at the Athenian democracy. But other Sophists, among them Hippias, put forward the demagogic formulas of human rights and of the freedom and equality of all to achieve the selfsame purpose—the overthrow of the bourgeois democracy.6
The metaphysical natural law of Plato as well as the more realistic one of Aristotle formed the high-water mark of moral and natural-law philosophy in Greek civilization. Stoicism, on the other hand, in a remarkable eclectic synthesis of single principles drawn from many philosophers, furnished in its system of natural law the terminology or word vessels into which the Church Fathers were able to pour the first conceptions of the Christian natural law and to impart them to the world of their time.
The danger of skepticism, to which the extreme rationalism of the Sophists lay exposed, was first clearly perceived by Socrates. The Sophists’ juggling of ideas and their paradoxes threatened to dissolve the notion of goodness and morality, just as their extremist social criticism and their libertarian ideology, directed in the name of the natural law against law and custom, called into question the value of the nomoi. Socrates did not merely teach the essence of goodness and justice by his inductive, question-and-answer method. Through the thesis that virtue consists in knowledge, he also showed that there exists a knowable objective world of such values as goodness, beauty, and justice, and that no one does evil for evil’s sake but because it somehow, culpably or through ignorance, appears to him as good. Wherefore knowledge means the contemplation of the idea of justice, and so on. The daimonion, conscience and its voice, he regarded as a reflection and testimony of these ultimate values and of the divinely instituted order of the world. Herein lies the significance of Socrates for the idea of the natural law. It does not lie in his frequently stressed fidelity to the law, although, to counteract the criticism of the Sophists, he placed so much emphasis upon the value of the laws that, out of respect for the law’s function of safeguarding right, he went so far as to condemn absolutely any disobedience to a particular unjust law.7
The great masters of Greece, Plato and Aristotle, also directed their attacks at the Sophists and their destructive criticism. Plato and Aristotle were chiefly, though not in the same degree, concerned with goodness and with its realization in the state. Their interest, however, did not center in the individual. It is quite common, rather, to speak of both as leaning toward state socialism or totalitarianism. For them, then, in accordance with the idea of order, the first and fundamental aim of justice is not freedom for its own sake, but order. Freedom is aimed at only so far as it realizes