The Origins of Natural Law Thinking in the Ideas of Ancient Greek Sophists: Protagoras and Antiphon

Protagoras and Antiphon are the first authors known to us who offered their views on the correlation between human nature, on the one hand, and the requirements of the law and positive morality, on the other. With Protagoras and Antiphon, the conventional character of law and morality, as well as the existence of a moral obligation to obey the law, became vital subjects of philosophical discussion. Protagoras, according to Plato’s testimony in the dialogues "Protagoras" and "Theaetetus", attempted to reconcile individual and public interests with the help of the concept of universal virtue, which all citizens of the polis should participate in. This attempt, however, is difficult to regard as successful, since, according to the logic of Protagoras, virtue is only a means for the survival of individuals and ensuring their security. While providing justification of the paramount importance and natural character of civic virtues, Protagoras at the same time allows for the possibility of following them only for appearance, as a cover for selfish motives.Antiphon views the contract between people as the sole and sufficient basis of law and morality. Approaching the problem from an individualistic point of view, Antiphon sharply contrasts nature and convention. Nevertheless, he considers the former rather in terms of benefits and harms of following it, and not as a source of objective moral prescriptions. According to this interpretation, nature and convention are two different worlds; one may chose which of them to follow, but it is impossible to reconcile them. Neither Protagoras, nor Antiphon offers any consistent concept of human nature, and that is why their ideas could not be characterized as natural law in the full sense of the word. Their views of nature do not yet contain fundamental standards, with which human law and conventional morality could be compared. The main weakness of both theories is their inability to give account of the social character of human nature. At the same time, the undoubted merit of Protagoras and Antiphon is the very statement of the question of the priority of nature or the convention, individual or public interests, as well as of the possibility of their harmonization. The ideas of two senior sophists played a decisive role in shaping the intellectual climate, in which, primarily in direct controversy with them, Plato and Aristotle produced much more elaborate concepts of human nature; and the natural law tradition emerged.