Quintilian, Institutio Oratoria 1.13-15:
“As soon as language began to be profitable and it became customary to abuse the gifts of eloquence, those who were considered educated abandoned their concern for morals. That concern, once abandoned, became something like a prize to less powerful intellects. Thereupon, certain people, entirely ignoring the labor of speaking well, returned to the formation of minds and the establishment of laws for life. They retained the stronger part of the study (if it can be divided) and arrogated to themselves that most insolent name, so that they alone would be called ‘students of wisdom’. Neither the greatest generals, nor those versed in the most important counsels and administration of the entire state ever dared to claim the name back for themselves: they preferred to do the greatest things, rather than simply promise them. I would readily concede that many of the ancient professors of wisdom taught noble things and even lived as they taught. But in our times, the greatest wickedness lies hidden under this name of philosopher, because they do not labor to be considered philosophers by virtue and study – rather, they make a pretentious show with a sullen looks and clothes differing from everyone else’s in order to cover up their degraded morals.”
Nam ut primum lingua esse coepit in quaestu institutumque eloquentiae bonis male uti, curam morum qui diserti habebantur reliquerunt: XIV. ea vero destituta infirmioribus ingeniis velut praedae fuit. Inde quidam contempto bene dicendi labore ad formandos animos statuendasque vitae leges regressi partem quidem potiorem, si dividi posset, retinuerunt, nomen tamen sibi insolentissimum adrogaverunt, ut soli studiosi sapientiae vocarentur; quod neque summi imperatores neque in consiliis rerum maximarum ac totius administratione rei publicae clarissime versati sibi umquam vindicare sunt ausi: facere enim optima quam promittere maluerunt. XV. Ac veterum quidem sapientiae professorum multos et honesta praecepisse et, ut praeceperint, etiam vixisse facile concesserim: nostris vero temporibus sub hoc nomine maxima in plerisque vitia latuerunt. Non enim virtute ac studiis ut haberentur philosophi laborabant, sed vultum et tristitiam et dissentientem a ceteris habitum pessimis moribus praetendebant.