From Aulus Gellius’ preface to Noctes Atticae – quoting Heraclitus, though in a variant of what is cited elsewhere.
The perusal of such collections will exhaust the mind through weariness or disgust, before it finds one or two notes which it is a pleasure to read, or inspiring to have read, or helpful to remember. I myself, on the contrary, having at heart that well-known saying of the famous Ephesian, “Much learning does not make a scholar,” did it is true busy and even weary myself in unrolling and running through many a scroll, working without cessation in all the intervals of business whenever I could steal the leisure; but I took few items from them, confining myself to those which, by furnishing a quick and easy short-cut, might lead active and alert minds to a desire for independent learning and to the study of the useful arts
quibus in legendis ante animus senio ac taedio languebit quam unum alterumve reppererit quod sit aut voluptati legere aut cultui legisse aut usui meminisse. Ego vero, cum illud Ephesii viri summe nobilis verbum cordi haberem, quod profecto ita est quibus in legendis ante animus senio ac taedio languebit quam unum alterumve reppererit quod sit aut voluptati legere aut cultui 12legisse aut usui meminisse. Ego vero, cum illud Ephesii viri summe nobilis verbum cordi haberem, quod profecto ita est πολυμαθίη νόον οὐ διδάσκει, ipse quidem volvendis transeundisque multis admodum voluminibus per omnia semper negotiorum intervalla in quibus furari otium potui exercitus defessusque sum, sed modica ex his eaque sola accepi quae aut ingenia prompta expeditaque ad honestae eruditionis cupidinem utiliumque artium contemplationem celeri facilique compendio ducerent, ipse quidem volvendis transeundisque multis admodum voluminibus per omnia semper negotiorum intervalla in quibus furari otium potui exercitus defessusque sum, sed modica ex his eaque sola accepi quae aut ingenia prompta expeditaque ad honestae eruditionis cupidinem utiliumque artium contemplationem celeri facilique compendio ducerent