the three Persons of the Trinity as merely nominal, but so did their opponents
who treated the Trinity as three abstract reals. The nominalism-realism dispute
was driven by purely internal dynamics of intellectual networks. When the
issue reemerged, it was because conflicts over metaphysical turf had come to
the point of pushing beyond Neoplatonism.
Aquinas disowns the implication that salvation occurs through the intellect
by participation in the sphere of general ideas. He leaves intact the hierarchy
of spheres of abstraction, but undercuts their importance by separating onto-
logical and epistemological grounds, arguing that humans lack the ability to
apprehend directly the world of universals, and instead know things only
through particulars. Aquinas was a compromiser, but his new mixed formula-
tion overthrew the Platonist ontological hierarchy and gave primacy to exist-
ence over essence (i.e., universal form). It was in response to this move that
Henry of Ghent (see note 15) formulated his doctrine that individuality is
merely a web of negations, against the backdrop of the higher reality of
positively existing Forms. Duns Scotus, in turn, trumped all the rival positions
by declaring that the essence of a thing is neither universal nor particular, but
depends on a general principle of particularity, what he calls haecceitas, “this-
ness.” By this route Christian philosophy, having cast off the Neoplatonic
position which identified highest religious reality with universals, finally came
into parallel with Nagarjuna, Dharmakirti, and the Buddhists with a concep-
tion of radically inexpressible particularity. The way was opened to an acon-
ceptual Christian mysticism, and at the same time to the revival of radical
nominalism such as that of William of Ockham.
In the Islamic sequence, debate over the question of nominalism and realism
breaks out via clashes between indigenous Muslim theologians and the Neo-
platonists—the equivalent of the clash between Christian anthropomorphism
and the Greek heritage. Al-Farabi (early 900s) imported these conceptions into
the branch of Islamic philosophers who continued the Greek traditions, but
these Muslim falasifa were generally Neoplatonists and followed the party line
on the superior reality of universals; what al-Farabi added was to formulate
the issue as a distinction between existence and essence. In the same generation
as al-Farabi, the theologian al-AshÀari argued that there are no universal
essences but only concrete and particular facts. Three generations later, the
themes of Neoplatonism and Islamic rational theology were brought together
by Ibn Sina, who formulated the concept of contingent being, merely possible
in itself but made necessary as the result of an external cause. That is to say,
the lower world participates in the necessity characteristic of the realm of
logical universals, but only in a derivative way, through the causal operation
of the one being necessary in itself, namely, God.
Ibn Sina’s contingency sharpens the sense in which the realm of particular
828 •^ Meta-reflections