In the seventh century, and for centuries afterward, a chief purveyor of the lore of the seven arts was the _Etymologiæ_, or _Origines_, of the Spanish bishop Isidore of Seville.[61] The work is an aggregation of summaries, not only of the seven arts, which occupy only three books of the twenty, but of medicine, law, holy writ, history, the hierarchy celestial and terrestrial, zoölogy, geography, metallurgy, agriculture, and crafts. Though it has no single guiding scheme, its brief chapters are grouped under headings fairly convenient for reference. It is a guide-book, rendering its first service when books were few and hard to get, and long continuing in vogue. In the thirteenth century Vincent of Beauvais,[62] undertaking more systematically a compend hardly less comprehensive, his vast _Speculum_, transferred to it whole passages from Isidore. Isidore appealed to the earlier middle age as a mediator not only of manifold lore, but especially of ancient tradition. The disciplines of the liberal arts are seven: first _grammatica_, i.e., skill in speaking; second, _rhetorica_, for the splendor and abundance of its eloquence deemed necessary especially in political questions;[63] third, _dialectica_, surnamed _logica_, which by subtlest arguments distinguishes the true from the false. I. ii. Isidore’s _grammatica_ has the usual contents, including _schemata_, _tropi_, and metric.[64] _Fabula_ and _historia_ reflect the ancient elementary exercises.[65] His second book contains both _rhetorica_ and _dialectica_. “_Rhetorica_ is the lore of speaking well on political questions to persuade [men of what is] just and good. It is called by a Greek name ἀπὸ τοῦ ῥητορίζειν, i.e., from wealth of speech. For in Greek speech is called ῥῆσις, and an orator ῥήτωρ. _Rhetorica_, moreover, is connected with _grammatica_. In the one we learn the lore of speaking correctly; in the other we perceive how to utter what we have learned. II. i. “This discipline was invented by the Greeks—Gorgias, Aristotle, Hermagoras, and transferred to Latin by Cicero and Quintilian.... The perfect knowledge of this discipline makes the orator. ii. “The orator, then, is a good man skilled in speaking: good, i.e., in nature, breeding, education; skilled in speaking, i.e., in expert eloquence. This consists of five parts (_inventio_, _dispositio_, _elocutio_, _memoria_, _pronuntiatio_) and in the function of persuading.”... iii.