Pro imaginibus
Lucian of Samosata
Lucian, Vol. 4. Harmon, A. M., editor. London: William Heinemann, Ltd.; Cambridge, MA: Harvard University Press, 1925.
That flatterers do not hesitate to lie for the sake of pleasing the objects of their praise, whereas those who really praise try to magnify what actually exists, is not the only distinguishing mark of each. They differ in a further point, and not a trivial one, that flatterers use hyperbole to the full extent of their powers, while those who really praise are discreet in precisely that particular and remain within their bounds.
These are a few out of many earmarks of flattery and of genuine praise which I give you so that you may not suspect all who praise you, but may distinguish between them and gauge each by his proper standard.
Come then, apply, if you will, both canons to my words, that you may discover whether they conform to this one or the other. If it had been some ugly woman whom I likened to the statue in Cnidos, I might indeed be accounted a liar, and a worse flatterer than Cynaethus. But since it was one whose beauty is known to all, the venture was not a salto mortale.