Plato. Plato in Twelve Volumes, Vol. 7 translated by R.G. Bury. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1966.
[358c]
Plato to Aristodorus wishes well-doing.
I hear that you now are and always have been one of Dion's most intimate companions, since of all who pursue philosophy you exhibit the most philosophic disposition; for steadfastness, trustiness, and sincerity—these I affirm to be the genuine philosophy, but as to all other forms of science and cleverness which tend in other directions, I shall, I believe, be giving them their right names if I dub them “parlor-tricks.1”
So farewell, and continue in the same disposition in which you are continuing now.
1 cf. Plat. Gorg. 486c, Plat. Gorg. 521d.