30 THE DECLINE AND FALL systems^ which have v^aried with the fashion of the times, the Arabians adopted the philosophy of the Stagirite, alike intelli- gible or alike obscure for the readers of every age. Plato wrote for the Athenians, and his allegorical genius is too closely blended with the language and religion of Greece. After the fall of that religion, the Peripatetics, emerging from their oljscurity, prevailed in the controversies of the Oriental sects, and their founder was long afterwards restored by the Mahomet- ans of Spain to the Latin schools. *"* The physics both of the Academy and the Lyceum, as they are built, not on observation, but on argument, have retarded the progress of real knowledge. The metaphysics of infinite or finite spirit have too often been enlisted in the service of superstition. But the human faculties are fortified by the art and practice of dialectics ; the ten pre- dicaments of Aristotle collect and methodize our ideas,*"^ and his syllogism is the keenest weapon of dispute. It was dexterously wielded in the schools of the Saracens, but, as it is more effectual for the detection of error than for the investigation of truth, it is not surprising that new generations of masters and disciples should still revolve in the same circle of logical argument. The mathematics are distinguished by a peculiar privilege that, in the course of ages, they may always advance and can never recede. But the ancient geometry, if I am not misinformed, was resumed in the same state by the Italians of the fifteenth centurv' ; and, whatever may be the origin of the name, the science of algebra is ascribed to the Grecian Diophantus by the modest testimony of the Arabs themselves."^ They cultivated with more success the sublime science of astronomy, which elevates the mind of man to disdain his diminutive planet and momentary- existence. The costly instruments of observation were supplied by the caliph Almamon, and the land of the Chaldeans still afforded the same spacious level, the same un- ^See Mosheim, Institut. Hist. Eccles. p. i8i, 214, 236, 257, 315, 338, 396, 438 &-C. * The most elegant commentary on the Categories or Predicaments of Aristotle may be found in the Philosophical Arrangements of Mr. James Harris (London, 1775, '" octavo), who laboured to revive the studies of Grecian literature and philo- sophy. ^'^ Abulpharagius, Dynast, p. 81, 222. Bibliot. Arab. Hist. torn. i. p. 370, 371. In quern (says the primate of the Jacobites) si immiserit se lector, oceanum hoc in genere (algebrae) inveniet. The time of Diophantus of Alexandria is unknown [probably 4th century .i.d.], but his six books are still extant, and have been illus- trated by the Greek Planudes and the Frenchman Meziriac (Fabric. Bibliot. Gra;c. torn. iv. p. 12-15). [His work entitled Wpiflni' "fa originally consisted of 13 books; only 6 are extant. Meziriac's ed. appeared in 1621, and Fermat's text in 1670 ; but these have been superseded by P. Tannery's recent edition.]