The sophists were in a sense traveling professors of rhetoric and other arts. Most of what we know about them comes from Plato in dialogues like the Gorgias and the Protagoras. Susan Jarratt, in Re-reading the Sophists, argues that Plato and Aristotle conducted what amounts to a smear campaign against the sophists, leaving us with a generally negative view. Plato’s problem was that sophistic rhetoric persuaded to belief rather than true knowledge. Aristotle did not like the fact that sophists, particularly Protagoras, tended to practice arguing both sides of the question, and to appeal to emotion rather than logic. However, Plato and Aristotle were authoritarian conservatives. Plato thought that we should be ruled by a philosopher king, with each citizen fulfilling his or her role in the social hierarchy, and Aristotle was tutor to Alexander the Great at the court of Phillip of Macedon. The sophists, on the other hand, taught that any citizen could become a leader, if he studied rhetoric with the sophist. Jarratt argues that the sophists are more democratic and egalitarian than either Plato or Aristotle, and thus more in tune with our own time.
Because most sophists traveled from city to city in a time when the cultural practices in one city could be very different from another, they were very sensitive to local customs and traditions, in part as a matter of survival. The Greek term for local “custom-law” is nomos. In general, the sophists did not believe in universal truths, focusing instead on what is persuasive in the here and now, in this place, at this moment. This concern for the moment is called kairos. Sensitivity to nomos and kairos puts the sophists quite at odds with Plato’s focus on metaphysical ideal forms and Aristotle’s focus on logic.
Another criticism of the sophists is that they taught for money. Isocrates, who probably should be considered a sophist himself, asks of the sophists “If the wisdom you teach is so priceless, why do you only charge a few coins?” Isocrates charged a lot. Socrates is always pressing sophists on the question of whether virtue can be taught, and because most sophists tend to say that it can, there are many jokes about sophists who demand that their students pay up front. The argument goes, “If you succeed in teaching virtue your students will pay; if they don’t pay, your teaching was unsuccessful anyway.”
I would argue that whether we think we are Platonists or Aristotelians or whatever, all English professors are in fact sophists by definition, because we claim that our instruction will cause our students to speak and write more effectively and to become better people, and we take money for it. However, I think we should wear this label proudly. To be a sophist is a worthy profession, Plato and Aristotle notwithstanding.