Seneca, Letters to Lucilius
88.36-37 (tr. Richard M. Gummere):
This desire to know more than is sufficient is a sort of intemperance. Why? Because this unseemly pursuit of the liberal arts makes men troublesome, wordy, tactless, self-satisfied bores, who fail to learn the essentials just because they have learned the non-essentials. Didymus the scholar wrote four thousand books. I should feel pity for him if he had only read the same number of superfluous volumes. In these books he investigates Homer's birthplace, who was really the mother of Aeneas, whether Anacreon was more of a rake or more of a drunkard, whether Sappho was a bad lot, and other problems the answers to which, if found, were forthwith to be forgotten. Come now, do not tell me that life is long!
Plus scire velle quam sit satis, intemperantiae genus est. Quid? Quod ista liberalium artium consectatio molestos, verbosos, intempestivos, sibi placentes facit et ideo non discentes necessaria, quia supervacua didicerunt. Quattuor milia librorum Didymus grammaticus scripsit. Misererer si tam multa supervacua legisset. In his libris de patria Homeri quaeritur, in his de Aeneae matre vera, in his libidinosior Anacreon an ebriosior vixerit, in his an Sappho publica fuerit, et alia quae erant dediscenda, si scires. I nunc et longam esse vitam nega!
Hat tip: Eric Thomson.