Doxa (δόξα) is a Greek word for the type of truth whose foundation derives from convention. Contrary to a truth that derives the nature of beings as such, without recourse to empirical examples, doxa relies on particular cases, myths, commonly held opinions, and traditional beliefs. Because the truth of doxa resides in the world of sense, that is, the sensible things of material existence, it pertains to things that change and come to be and cease to be. In the dialogues, Plato opposes these types of objects - the particular examples which over time are shrouded in myth, stories, traditions and customs - to the unchanging truth of Forms. The problem of doxa is that doxa represents a sedimented form of visible truth, the truth of 'appearances.' The problem of the philosopher, however, at least according to Plato, is precisely to determine the connection or gap between 'appearances' and reality. The philosopher's job is to investigate reality but because he finds himself in the world, he must, according to the Phaedrus dialogue, become an expert at helping hearers pass through resemblances (262b).
According to Plato, the difference between the philosopher who deals in such image-making in order to cause hearers to advance, through resemblances, to the truth) can be distinguished from the activity of the sophist insofar as the images arising from philosophical discourse are able to retain their connection to the original form, in other words, reality itself. Sophists, on the other hand, are content to persuade others as to the value of their arguments through artistry, by their ability to combine words and arguments in aesthetic arrangement.
- Plato (1914). Plato I of Plato. Harvard University Press. ISBN 13: 978-0-674-99040-1.