Letters 94.55

We should, therefore, have a guardian, as it were, to pluck us continually by the ear and dispel rumours and protest against popular enthusiasms. For you are mistaken if you suppose that our faults are inborn in us; they have come from without, have been heaped upon us. Hence, by receiving frequent admonitions, we can reject the opinions which din about our ears.

Seneca, Letters to Lucilius 94.55, translated by Richard Mott Gummere