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

the act must be temporal, and if the agent is eternal the act
must be eternal. But to impose as a condition that the act
must be posterior in time to the agent is impossible, for when
a man moves his finger in a bowl of water, the water moves
at the same time as the finger, neither before nor after, for if
the water moved later than the finger, finger and water would
have to be in one and the same space before the water
disconnected itself, and if the water moved before the finger,
the water would be separated from the finger and
notwithstanding its anteriority would be an effect of the
finger performed for its sake. But if we suppose the finger
eternally moving in the water, the movement of the water will
be eternal too, and will be, notwithstanding its eternal
character, an effect and an object, and the supposition of
eternity does not make this impossible. And such is the
relation between the world and God.
I say:
This is true in so far as it concerns the relation of movement and mover,
but in regard to the stable existent or to that which exists without moving
or resting by nature (if there exist such things ) and their relation to their
cause, it is not trues Let us therefore admit this relation between the agent
and the world only in so far as the world is in motion. As for the fact that
the act of every existent must be conjoined with its existence, this is true,
unless something occurs to this existent which lies outside its nature, or
one or another accident occurs to it,b and it is immaterial whether this act
be natural or voluntary. See, therefore, what the Ash’arites did who
assumed an eternal existent, but denied that He acted during His eternal
existence, but then, however, allowed this agent to act eternally in the
future, so that the eternal existence of the Eternal would become divided
into two parts, an eternal past during which He does not act and an eternal
future during which He acts! But for the philosophers all this is confusion
and error.
Ghazali answers the philosophers on the question of priority:
We do not say that the simultaneity of agent and act is
impossible, granted that the act is temporal, e.g. the motion
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