Letters 106.12

Wisdom is a plainer thing than that; nay, it is clearly better to use literature for the improvement of the mind, instead of wasting philosophy itself as we waste other efforts on superfluous things. Just as we suffer from excess in all things, so we suffer from excess in literature; thus we learn our lessons, not for life, but for the lecture-room. Farewell.

Seneca, Letters to Lucilius 106.12, translated by Richard Mott Gummere