653

Cf p. 311, above.

654

 This is not correct.

655

This is a translation of stoicheia, elementa. In addition to the bibliographical references in GAL, there is a recent study by E. B. Plooij, Euclid's Conception of Ratio and his Definition of Proportional Magnitudes as Criticized by Arabian Commentators, (Leiden dissertation) (Rotterdam, [1950]). Cf. also, 2:365, above.

656

Or "most extensive." However, since it is considered as an introduction to geometry, the above translation may be preferable.

657

He died ca. 260 [873]. Cf. GAL, I, 205 f.; Suppl., I, 366 ff.

658

He died in 288 [901]. Cf. GAL, I, 217 f.; Suppl., I, 384 ff.

659

That is, al-Hajjaj b. Yusuf b. Matar. Cf. GAL, 1, 203; Suppl., I, 363.

660

As explained in the definitions of the tenth book of Euclid, a square is called rhton, munfaq "rational," whereas its sides belong among the elements that "have power over" (ai dunamenai, al-qawiyah ala) the production of rational quantities and are called "irrational."

661

This cannot be the early translator Ibrahim b. ay-Salt; cf. GAL, Suppl., I, 371. Ibn Khaldun presumably had in mind Abu s-Salt Umayyah b. 'Abd-al-'Aziz b. Abi s-Salt, who lived ca. 460 [1067/68]. Cf. GAL, I, 486 f.; Suppl., I, 889. He is credited with a work on geometry by Ibn Abi Ulaybi'ah, 'Uyun al-anba', ed. Muller (Konigsberg & Cairo, 1882-84), II, 62, 1. 22. Cf. also below, p. 135.

662

The famous agewmetrhtoz mhdeiz eisitw, which appears in Elias' commentary on the Categories and was well known to the Arabs. It entered Arabic literature in connection with the introductions to Aristotelian phi­losophy. Cf al-Farabi, Fi-ma yanbaghi an yuqaddam qabl 'ilm al falsafah, ed. and tr. F. Dieterici: Alfarabi's Philosophische Abhandlungen (Leiden, 1890, 1892), pp. 52, 87.

663

Cf. also 2:365, above.

664

For haykal, pl. hayakil, cf. 1:151 (n. 172), above.

665

They lived in the ninth century. Cf. GAL, I, 216 f.; Suppl., I, 382 f. 666

666

Hawa 'it "gardens." Or does Ibn Khaldun mean the fixing of the boundaries of buildings?

667

De Slane notes that Ibn Khaldun should have said "longitudes."

668

Al-Hasan (Husayn) b. al-hasan (Husayn) b. al-Haytham (Alhazen), from ca. 364 [9651 to 430 [10391. Cf. GAL, I, 469 f.; Suppl., I, 861 fi.