64 McGinnis
theories, however, we must consider certain developments within the
Greek scientifi c tradition that were to infl uence Arabic discussions con-
cerning nature.HISTORICAL BACKGROUND
The Arabic translators’ choice of tabı ̄‘a to render Aristotle’s notion of phu-
sis was not simply happenstance; rather, it seemed to be the product of
developments in the Greek Aristotelian commentary tradition itself. Ar-
istotle, having defi ned nature as a principle of change, further identifi ed
a thing’s nature with its matter and form.^15 He additionally argued that
although the individual instances of a form- matter composite—such as a
particular person, a given tree, a quantity of water, and the like—inevita-
bly come to be at some time and cease to be at some time, matter and form
absolutely—that is, the underlying stuff and what it is to be human, tree,
water, and the like—are eternal and exist necessarily.^16 Consequently, for
Aristotle the matter of and forms in the universe need no effi cient cause to
explain their existence; rather, what needs explanation according to Aris-
totle is the cause of the changes in the universe, which Aristotle explained
by appealing to an unmoved mover as an ultimate object of desire.^17 In
this respect Aristotle’s unmoved mover, or “God,” is not an effi cient cause
of the universe’s existence at all, but only a fi nal cause of its motion.
Such a position came to be unacceptable to a number of later Neopla-
tonists. Neoplatonism had its origins in the Enneads of Plotinus (205–270 /
71 CE) with its appeal to “the One,” which later thinkers would identify
with God, and which in a real sense was considered to be beyond exis-
tence and being, but from whom all being or existence emanates. Thus
Proclus (412–485 CE), whose own thought was much indebted to that of
Plotinus, complained against Aristotle that it was not enough that God
should be the fi nal cause of the universe, as Aristotle had maintained;
one must also show that God is the effi cient cause, the very source, of the
universe’s existence. Unlike earlier Neoplatonists, such as Plotinus and
Proclus, later Neoplatonists were quite keen to show the harmony of the
thought between Plato and Aristotle. Accordingly, as part of their attempt
to reconcile these two, later Neoplatonists wrote commentaries on a num-
ber of Aristotle’s works, which were in turn either translated into Arabic
or were known in paraphrastic versions. These works greatly shaped the
reception of Aristotle in the Arabic world.^18 Thus in response to Proclus’s
complaint, his own student, Ammonius (ca. 440–520 CE), maintained
that despite appearances to the contrary, and notwithstanding what Aris-