Basically, the Sophists (Empedocles, Protagoras, Gorgias, and many others) believed that humans could not gain access to transcendent truth. Absolute certainty, they believed, could never be attained. However, by pitting various perspectives and arguments against each other, the Sophists believed that people could achieve useful truths, in order to decide important matters (much like our adversarial trial system). Not only did the Sophistic philosophy undermine some of the pagan religious traditions of the time—the young Sophist was unlikely to make a sacrifice to the Delphic Oracle and wait to receive her divine guidance about a matter—but the Sophists would teach anyone, not just the children of aristocrats. So, the Sophists were often viewed as dangerous rebels, traveling around, teaching kids that they could better themselves through sophisticated rhetorical skills.
Protagoras, professional sophist, is most famous for his statement, “Man is the measure of all things, of things that are, that they are, and of things that are not, that they are not.” He claimed that all perceptions are true for their perceiver, though he admitted that some perceptions may be more reliable than others. For instance, a healthy man’s ideas may be better than a sick man’s. According to Protagoras, the Sophist’s job was to help people perceive the world more effectively. Though he had long been an adviser to the Athenian leader, Pericles, Protagoras was exiled from Athens in 415 for impiety as a direct result of writing “On the Gods,” a work in which he proclaimed that human beings were incapable of knowing whether the gods existed or not. His books were subsequently burned, and Protagoras fled to his home city of Abdera. Since the majority of Protagoras’ works were destroyed, there remain today only a few of his fragments. However, we know a fair amount about his doctrines because of the efforts of Plato, Aristotle and Sextus Empiricus. In spite of difficulties in Athens, it seems that Protagoras was held in high regard, for a statue of him was erected with those of Plato and Aristotle in the Serapeum in Egypt during the Hellenistic Period. Aside from his philosophical duties, Protagoras had a reputation as a law-maker; in 443, he drafted the constitution of Thurii at the request of his close friend, Pericles.
Gorgias (ca. 480-380 B.C.E)
“Nothing exists,” said Gorgias; “if something does exist, we cannot know it; if we come to know it, we cannot teach it to others.” If reality is relative to the knowledge of empirical data, there is no reality, really. Hence nothing exists. If it should exist, it would be impossible for it to be known by us as it is in itself, because we can be witnesses only of the impressions in their sensible immediacy, and no one assures us that this is representative of reality. Nor can we teach others what we know, since everyone has a different way of feeling. Hence the only thing remaining is the use of the word, and Gorgias affirmed that all things can appear true and just, if oratorical power is capable of revealing things as true and just, beyond every pretension of reality of content.
Gorgias was such an eleoquent persuader, that he convinced the Athenian military to come to the aid of his small, Sicilian hometown, Leonini, which was under siege by its neighbor, Syracuse. Unfortunately, the war between Athens and Syracuse ultimately debilitated Athens, putting an end to what is often considered the golden age of Greek culture. Eventually, the Roman Empire would replace the league of Greek city-states, and history could look back and blame Gorgias. This may be why Gorgias is demonized by Plato, in his Socratic dialogue entitled “Gorgias.” In the dialogue, Gorgias is shown in his old age, somewhat addled and easily baffled by the more agile-minded Socrates.