Sophist by Plato is a dialogue primarily between the characters of Socrates and Theaetetus, but others are also involved. Socrates is attempting to explain to the young man what a Sophist is and what the ideas of philosophy, purification, and education really mean and do for people in a society.

There are several main points that Plato is trying to achieve in this work. The first is to give an understanding of what a Sophist does—the function they perform, especially in a society that already has philosophers, teachers, and statesmen. The Sophist is more than just a teacher or master of rhetoric—they are almost a physical and spiritual guide for young, enterprising individuals. A Sophist has the goal of purifying the body and mind of his pupils. He does this by educating and leading them in several areas.

To purify the body, he leads them in instruction on medicine and physical education so that they can become physically fit and healthy. The reason behind this, as is explored in Plato's Republic with the definition of the guides of civilization, is to make moral, strong leaders who will be fit and healthy enough to last for a long period of time.

The act of purifying the mind deals with removing the two evils inherent in people—vice and ignorance. With a proper philosophical education and motivation, the individuals can strive to cure vice by living morally upright lives and engaging in honest work. To dispel ignorance, the Sophist instructs them in a wide range of subjects so that their knowledge may be complete and they will be able to speak at length about any subject.

The Sophist, according to Plato, is essentially a man of many hats and is therefore extremely difficult to describe. He is referred to as a juggler and magician at times and reduced to an idea that can only be possible in child's play or must be some fabricator of reality. Plato assures the characters, however, and the reader, that true Sophists exist and are there as guides to mold the leaders of the nation.