It was no more to the credit of Epaphroditus that he wished to have a philosophic slave, than it is to the credit of an illiterate millionaire in modern times that he likes to have works of high art in his drawing-room, and books of reference in his well-furnished library.
Accordingly, since Epictetus must have been singularly useless for all physical purposes, and since his thoughtfulness and intelligence could not fail to command attention, his master determined to make him useful in the only way possible, and sent him to Caius Musonius Rufus to be trained in the doctrines of the Stoic philosophy.
Musonius was the son of a Roman knight.

His learning and eloquence, no less than his keen appreciation of Stoic truths, had so deeply kindled the suspicions of Nero, that he banished him to the rocky little island of Gyaros, on the charge of his having been concerned in Piso's conspiracy.

He returned to Rome after the suicide of Nero, and lived in great distinction and respect, so that he was allowed to remain in the city when the Emperor Vespasian banished all the other philosophers of any eminence.
The works of Musonius have not come down to us, but a few notices of him, which are scattered in the _Discourses_ of his greater pupil, show us what kind of man he was.

The following anecdotes will show that he was a philosopher of the strictest school.
Speaking of the value of logic as a means of training the reason, Epictetus anticipates the objection that, after all, a mere error in reasoning is no very serious fault.

He points out that it _is_ a fault, and that is sufficient.