Letters 109.18

Why do you ask of me a useless knowledge? You have promised great things; test me, watch me! You assured me that I should be unterrified though swords were flashing round me, though the point of the blade were grazing my throat; you assured me that I should be at ease though fires were blazing round me, or though a sudden whirlwind should snatch up my ship and carry it over all the sea. Now make good for me such a course of treatment that I may despise pleasure and glory. Thereafter you shall teach me to work out complicated problems, to settle doubtful points, to see through that which is not clear; teach me now what it is necessary for me to know!” Farewell.

Seneca, Letters to Lucilius 109.18, translated by Richard Mott Gummere