Didascalicon, Book III: the art of study (discipline and method)
Chapter IV. On the two kinds of writings
There are two kinds of writings. The first kind is of those which are properly called arts. The second is of those which are appendages of the arts. The arts are those which are placed under philosophy, that is, which have some certain and determinate matter of philosophy, as grammar, dialectic and the like. The appendages of the arts are those which pertain to philosophy only in part, that is, which are occupied with some matter outside philosophy; yet sometimes they touch scattered and confusedly some things taken from the arts, or, if a simple narration, prepare the way to philosophy. Of this kind are all the songs of the poets, such as tragedies, comedies, satires, also heroic and lyric and iambic, and certain didactic works; also fables and histories; also the writings of those whom we are now accustomed to call philosophers, who are used both to extend a brief matter by long circuits of words, and to obscure an easy sense by tangled speech, or also to compile diverse things together, as if making one picture of many colors and forms. Note what I have distinguished for you. There are two: arts and appendages of the arts. But between these the distance seems to me so great that, as he says:
As much as the pale olive yields to the lithe willow, as much as the humble willow to the crimson hollow-leaved rose.
(Virgil, Eclogues.) So that whoever desires to attain knowledge, if, leaving the truth of the arts, he wishes to entangle himself with the rest, will bear a matter of labor not only very great but infinite, and a scanty fruit. In short, the arts without their appendages can make a perfect reader; the appendages without the arts can confer nothing of perfection. Above all, since they have in themselves nothing to be desired by which to invite the reader, except what is derived from the arts and accommodated; nor does anyone seek in them anything but what belongs to the arts. Wherefore it seems to me that effort is to be given first to the arts, where the foundations of all are, and pure and simple truth is opened; especially to those seven which I have named before, which are the instruments of all philosophy. Then the rest also, if there is leisure, may be read, because sometimes light things mixed with serious are wont to delight more, and rarity makes a good precious. So in the midst of a fable’s course, a sentence found we sometimes retain more eagerly. Nevertheless, in the seven liberal arts is the foundation of all doctrine, which above all others are to be kept at hand, as being those without which the philosophic discipline is wont neither to explain nor to define anything.