Letters 109.5

Because he will bring joy to the other, he will strengthen his faith, and from the contemplation of their mutual tranquillity the delight of both will be increased. Moreover, they will communicate to each other a knowledge of certain facts; for the wise man is not all-knowing. And even if he were all-knowing, someone might be able to devise and point out short cuts, by which the whole matter is more readily disseminated.

Seneca, Letters to Lucilius 109.5, translated by Richard Mott Gummere