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

I say:
thing occurs, does not produce an impression on his
imagination, just as, when he sees the water after having
previously seen it in one and the same vessel and in the
same quantity, no new impression is produced. And he may
see another hand, different in colour and size, and then
there occurs to him another colour and another size, but
there does not happen to him a new form of hand, for the
small black hand has in common with the big white hand the
position of its parts, differing from it in colour, and of that in
which the second hand agrees with the first no new form is
produced, since both forms are identical, but the form of the
things in which they differ is renewed. And this is the
meaning of the universal both in sensation and in intellect,
for when the intellect apprehends the form of the body of an
animal, then it does not acquire a new form of corporeity
from a plant, just as in imagination the form of two stretches
of water perceived at two different times need not be
renewed; and the same happens with all things that have
something in common.
But this does not permit one to assert the existence of a
universal which has no position whatever, although the
intellect can judge that there exists something that cannot be
pointed at and has no spatial position; for instance, it can
assert the existence of the creator of the universe, with the
understanding, however, that such a creator cannot be
imagined to exist in matter, and in this kind of reality the
abstraction from matter is in the intelligible itself and is not
caused by the intellect and by thinking. But as to the forms
acquired from material things, this happens in the way we
have mentioned.
The meaning of the philosophical theory he relates is that the intellect
apprehends, in relation to the individuals which have a common species, a
single entity, in which they participate and which is the quiddity of this
species without this entity’s being divided into the things in which the
individuals qua individuals are divided, like space and position and the
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