Philostratus, Life of Apollonius of Tyana 8.7.3:

 

But I anyhow affirm wizards (goetes) to be professors of a pseudo-liberal art, for they get men to believe that the unreal is real, and to distrust the real as unreal, and I attribute all such effects to the imaginative fancy of the dupes; for the cleverness of this art is relative to the folly of the persons who are deceived by them, and who offer the sacrifices they prescribe; and its professors are given up wholly to filthy lucre, for all their parade of skill is devised by them in hope of gain, and they are always on the look out for big fortunes, and they try to persuade people who are passionately attached to something or another that they are capable of getting everything for them. (Loeb trans.)