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

priority of the unmoved being to the thing in motion to the priority existing
between two things in motion is in error; since it is only true of each one in
pairs of moving things that, when it is brought in relation to the other, it is
either simultaneous with it or prior or posterior in time to it. It is the later
philosophers of Islam who made this mistake, since they enjoyed but
slight comprehension of the doctrine of the ancients. So the priority of this
one being to the other is the priority of the unchanging timeless existence
to the changing existence which is in time, and this is an altogether
different type of priority. It is therefore not true of these existences that
they are simultaneous, or that the one precedes the other, and Ghazali’s
observation that the priority of the Creator to the world is not a temporal
priority is true. But the posteriority of the world to the Creator, since He
does not precede the world in time, can only be understood as the
posteriority of effect to cause,’ for posteriority and priority are opposites
which are necessarily in one genus, as has been shown in the sciences.’
Since therefore this priority is not in time, the posteriority also cannot be in
time, and we have the same difficulty all over again: how can the effect be
delayed after the cause when the conditions of acting are fulfilled? The
philosophers, however, since they do not recognize a beginning in the
totality of this existence in moti/n, are not touched by this difficulty, and it is
possible for them to indicate in what way the temporal beings proceed
from the eternal. One of their proofs that existence in motion has no
beginning, and that in its totality it does not start, is that, when it is
assumed to start, it is assumed to exist before its existence, for to start is
a movement, and movement is of necessity in the thing in motion, equally
whether the movement is regarded as taking place in time or at an
instants Another proof is that everything that becomes has the potentiality
of becoming before it actually becomes, although the theologians deny
this (a discussion with them on this point will follow); now potentiality is a
necessary attribute of being in motion, and it follows necessarily that, if it
were assumed to become, it would exist before its existence. What we
have here are only dialectical arguments; they have, however, a much
greater plausibility than what the theologians advance.
As for Ghazali’s words:
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