The Learned and the Foolish

Quintilian 10.7.22 (tr. Donald A. Russell):

Those who want to seem learned to the foolish seem fools to the learned.

qui stultis videri eruditi volunt, stulti eruditis videntur.

The Latin is mangled in Jon R. Stone, The Routledge Dictionary of Latin Quotations: The Illiterati's Guide to Latin Maxims, Mottoes, Proverbs, and Sayings (New York: Routledge, 2005), p. 97:

If you quote this saying of Quintilian as it appears in the Routledge Dictionary, you will truly be exposed as illiterate.