XI. Here, however, it is necessary to understand, that this is the nature of time, viz. that it is the length of such a life as we have before mentioned, proceeding in equable and similar mutations, which themselves proceed in a silent course; this length also possessing a continuity of energy. If, therefore, we again in words make this power to revert, and the life of it to cease which it now possesses, and which is unceasing, and will never end, because it is the energy of a certain ever-existing soul, not directed to itself, nor in itself, but employed in producing and generating; — if, therefore, we suppose this power no longer energizing, but ceasing from this energy, and also this part, of the soul converted to real being and eternity, and abiding in quiet, what will there any further be besides eternity ? What will any longer be another and another, where all things abide in one ? And what will be prior or posterior, or more extended ? Where, likewise, will the soul any further betake itself to any other thing than that in which it is ? Or rather, neither will it betake itself to this. For in this case, it must have first departed from it, in order that it may accede to it; since neither is it the sphere itself (of the universe) which had not an existence prior to time. For this sphere exists, and is moved in time. And though time should stop, this sphere still continuing to energize, we should nevertheless measure the duration of its permanency, as long as the permanency of eternity is external to it. If, therefore, this sphere becoming quiescent and united, time is taken away, it is evident that the commencement of its motion, round the earth, and this its life, generate time. Hence, also, it is said (in the ” Timaeus ” of Plato), that time was generated together with the universe, because soul produced it in conjunction with the universe. For in an energy of this kind, this world was generated. And this energy indeed is time, but the universe is in time. If, however, some one should say, that the circulations of the stars are also denominated by Plato times, he should recollect that he says these were generated for the purpose of rendering time manifest and distinct, and that the measure of it might be conspicuous to us. For since it was not possible for time itself to be bounded by soul, nor for each part of it to be measured by us, since it is invisible and incomprehensible, and especially since this is impossible to those who do not know how to numerate, — hence the Demiurgus made day and night, through which mankind were enabled to apprehend two things by their difference; from which, as Plato says, they arrived at the conception of number. Afterwards receiving the interval produced by the motion of the sun from the east to the east again, they apprehended what was the quantity of time, the form of the motion being equable; adhering to which, we use a thing of this kind as a measure of time. For time itself is not a measure. For how could it measure ; and what would it say if it measured ? Will it say this thing is as much in quantity as I am ? Who therefore is it that says I ? Is it that according to which the measure subsists ? Has it not therefore an existence in order that it may measure, but is not a measure ? Hence the measured motion of the universe will be according to time. And time will not be the measure of motion, according to that which it is, but according to accident, so that being something else prior to this, it renders the quantity of the motion manifest. One motion also being assumed in so much time, and being frequently enumerated, leads to a conception of the quantity of time that is past. So that if some one should say that motion and circulation, after a – certain manner, measure time as much as possible, as manifesting in their quantity the quantity of time, which cannot in any other way be assumed or understood, he indeed will not adduce an absurd manifestation of time. Hence, that which is measured by circulation, viz. which is manifested, and not generated by it, will be time. And thus the measure of motion is that which is measured by a definite motion, and is measured by it, as being different from it. For if that which measures was one thing, and that which is measured another, but is measured accidentally; in this case, it would be just as if some one should say that what is measured by a cubit is magnitude, but should not say what that is which defines the magnitude. It would also be just as if some one not being able to render motion itself manifest on account of its indefinite nature, should say that motion is that which is measured by place. For assuming the place which motion passes through, he will say that the quantity of the motion is equal to the quantity of the place.