In my view, many men would have attained to wisdom, had they not supposed they had already done so, had there not been certain inner failings they had pretended were not there, and certain ones they had passed by with their eyes shut. For you have no reason to judge that other people’s flattery is more destructive to us than our own. Who ever dares to tell himself the truth? Who, though he stands in the midst of a herd of sycophants who sing his praises, is not despite all this his own greatest flatterer?

From Seneca’s “On the Tranquility of the Mind” in Dialogues and Essays, translated by John Davie, Oxford: Oxford University Press, 2007, pp. 114-115.