Decree of Diopeithes

The Decree of Diopeithes was instituted by the opponents of Pericles in an attempt to discredit Anaxagoras.[1] The date is not exact, as sources give different years. Some sources list the arrest and trial of Anaxagoras as early as 437/6 BCE,[2] others at 434 BCE,[3] and still others 432.[4] The charges stemmed from his observations of the heavens and asserting that there were no lunar and solar deities.[5][6]

According to the Oxford Classical Dictionary, the only reference to this decree comes from Plutarch's Pericles:

And Diopithes proposed a decree, that public accusations should be laid against persons who neglected religion, or taught new doctrines about things above, directing suspicion, by means of Anaxagoras, against Pericles himself.

— Plutarch, Pericles, para. 32

A reference to the trial of Anaxagoras was mentioned by Plato in Apology:

That is an extraordinary statement, Meletus. Why do you say that? Do you mean that I do not believe in the godhead of the sun or moon, which is the common creed of all men?

I assure you, judges, that he does not believe in them; for he says that the sun is stone, and the moon earth.

Friend Meletus, you think that you are accusing Anaxagoras; and you have but a bad opinion of the judges, if you fancy them ignorant to such a degree as not to know that those doctrines are found in the books of Anaxagoras the Clazomenian, who is full of them.

— Plato, Apology