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

extension is nothing but time, and to call it timeless eternitys is senseless.
And since time is connected with possibility and possibility with existence
in motion, existence in motion has no first term either. And the assertion of
the theologians that everything which existed in the past had a first term is
futile, for the First exists in the past eternally, as it exists eternally in the
future. And their distinction here between the first term and its acts
requires a proof, for the existence of the temporal which occurs in the past
is different from the existence of the eternal which occurs in the past. For
the temporal which has occurred in the past is finite in both directions, i.e.
it has a beginning and an end, but the eternal which has occurred in the
past has neither beginning nor end.’ And therefore, since the philosophers
have not admitted that the circular movement has a beginning, they
cannot be forced to admit that it has an end, for they do not regard its
existence in the past as transitory, and, if some philosopher does regard it
as such, he contradicts himself and therefore the statement is true that
everything that has a beginning has an end. That anything could have a
beginning and no end is not true, unless the possible could be changed
into the eternal, for everything that has a beginning is possible. And that
anything could be liable to corruption and at the same time could be
capable of eternity is something incomprehensible’ and stands in need of
examination. The ancient philosophers indeed examined this problem, and
Abu Hudhail agrees with the philosophers in saying that whatever can be
generated is corruptible, and he kept strictly to the consequence which
follows from the acceptance of the principle of becoming. As to those who
make a distinction between the past and the future, because what is in the
past is there in its totality, whereas the future never enters into existence
in its totality (for the future enters reality only successively), this is
deceptive, for what is in reality past is that which has entered time and that
which has entered time has time beyond it in both directions and
possesses totality. But that which has never entered the past in the way
the temporal enters the past can only be said in an equivocal way to be in
the past; it is infinitely extended, with the past rather than in the past, and
possesses no totality in itself, although its parts are totalities. And this, if it
has no initial term beginning in the past, is in fact time itself. For each
temporal beginning is a present, and each present is preceded by a past,
and both that which exists commensurable with time, and time
commensurable with it, must necessarily be infinite. Only the parts of time
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