philosophy from the pre-Socratics down through the Hellenistic Skeptics; the
showdown between late Neoplatonism and Christianity in the 400s c.e.; and
the growth of Islamic (and in parallel to it Jewish) philosophy from the early
Baghdad and Basra schools of the 700s through 1200, culminating in the
positions of Ibn Sina, al-Ghazali, Ibn Rushd (Averroës), and Maimonides. The
classic Greek period mixed together arguments pro and con polytheism, mono-
theism, and pantheism, without focus on a transcendent world-creating God.
The first carefully articulated proofs on this terrain emerged with Proclus, at
the end of the Neoplatonic school, who argued against Christianity for the
eternity of the world. His grandpupils Simplicius and John Philoponus, con-
verts to Christianity, refuted Neoplatonic arguments from the monotheist side.
It was the synthesis between the networks of abstract philosophy and anthro-
pomorphic Christian monotheism that generated these first comprehensive
proofs.^19
Islamic philosophy was no mere passive transmission belt for Greek phi-
losophy. The first community of abstract argument comprised the indige-
nous development of kalam, rational theology, in the MuÀtazilite school. It
was only after Islamic philosophy experienced a turning point, the rising power
of scriptural conservatives after 835, that MuÀtazilite creativity went on the
defensive, leaving a vacuum in the attention space into which Greek imports
were now welcomed. The first rounds of Muslim philosophy centered on
questions of free will and predestination, and of proofs of the unity and justice
of God, arising directly from indigenous theological controversy. There devel-
oped an acute consciousness of what is proven and not proven. Various kinds
of proofs of the existence of God were recognized, and distinguished from
proofs of the unity of God and of the creation of the world ex nihilo. Formation
of a conservative opposition raised the level of abstraction, leading to acute
discussions of primary and secondary accidents, of the contingency of creation,
of particularity as opposed to universals, and of causality. Ibn Sina created his
version of the cogito in the competition over rising standards of proofs, adding
his distinctions of necessary, possible, and contingent being, to come up with
a proof of God as being purely necessary in itself alone. Al-Ghazali is a
response to Ibn Sina’s rationalism, Averroës a response to al-Ghazali. The
mainline of the epistemology-metaphysics sequence in Islamic philosophy is a
series of moves along the debating space of proofs of God. In the Greek
networks, and for later Christian philosophy, Simplicius and Philoponus are
minor figures, receiving little attention; in medieval Muslim and Jewish phi-
losophy, it is the formulators of the proofs of God who are the stars.
When intellectual life came alive in medieval Christendom, proofs of God
became a standard turf for tests of philosophical skill, not primarily for
converting unbelievers but for precedence in the intellectual community. It was
Sequence and Branch in the Social Production of Ideas^ •^833