Tahafut_al-Tahafut-transl-Engl-van-den-Bergh

I say:
composed of genus and species, and this is a kind of
plurality, and the philosophers affirmed that this kind also
must be denied of the First Principle.
Fifthly: the plurality which results from the duality of a
quiddity and the existence of this quiddity; for man before his
existence has a quiddity, and existence occurs to it and
enters into relation with it, and in this way the triangle has a
quiddity, namely, it is a figure surrounded by three sides, and
existence is not a component of this quiddity, and therefore
the intellect can perceive the quiddity of man and the
quiddity of a triangle without knowing whether they exist in
the external world or not. z If existence were a component of
the quiddity to which it is added, the fixation of this quiddity
in the mind before its existence could not be imagined.
Existence stands in a relation to quiddity, whether in a
necessary inseparable relation, for instance, heaven, or in
an accidental relation occurring after a thing’s non-existence,
like the quiddity of man in respect of Zaid or Amr and the
quiddity of accidents and forms which occur. ‘ And the
philosophers affirm that this kind of plurality also must be
denied of the First Principle. They say that the First Principle
has no quiddity to which existence is joined, but existence is
necessary to it, as is quiddity to the other entities. Therefore
necessary existence is at once a quiddity, a universal reality
and a real nature, in the same way as a man, a tree, and
heaven are quiddities. For if the necessary existent needed
a quiddity for its existence, it would be consequent on this
essence and would not constitute it, and the consequent is
something secondary and an effect, so that the necessary
existent would be an effect, and that would be in opposition
to its being necessary.
These arc the theories of the philosophers which Ghazali mentions on
the subject of their denial of plurality in the Monad. Then he begins to
show how they contradict themselves on this question. We must now first
examine these statements which he ascribes to them, and explain the
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