LECTURE 2 (251 a 8-252 a 3)

ARGUMENTS FOR THE ETERNITY OF MOTION

             971. After he has raised the question of the eternity of motion, he intends here to show that motion is eternal.

             This discussion is divided into two parts. First he proves his position. Secondly, where he says, 'The arguments that may . . .' (252 b 7), he answers possible objections to the contrary.

             Concerning the first part he makes two points. First he gives arguments to prove the eternity of motion. Secondly, where he says, '. . . and cannot have existed . . .' (252 a 4), he gives arguments against the opinions of the philosophers who hold the contrary.

             Concerning the first part he makes two points. First he shows that there has always been motion. Secondly, where he says, 'The same reasoning . . .' (251 b 29), he shows that there always will be motion.

             Concerning the first part he makes two points. First he proves the proposition with an argument taken from motion. Secondly, where he says, 'Further, how can there be . . .' (251 b 10), he uses an argument taken from time.

             Concerning the first part he makes three points. First he sets forth a certain thing which is necessary for the following proof. Secondly, where he says, 'Moreover, these things also . . .' (251 a 17), he introduces the proof of the proposition. Thirdly, where he says, 'For some things cause . . .' (251 a 29), he shows the necessity of this proof.

             972. He says, therefore, first that to prove the proposition, we ought to begin with those things which have already been determined in the Physics, so that we may use them as principles. By this he wants us to understand that the preceding books, in which he discussed motion in general and which are thus universally called de Naturalibus, are distinct from Book VIII, in which he begins to apply motion to things.

             He assumes, therefore, what is said in Physics, III, namely, that motion is the act of a mobile object insofar as it is mobile. It is apparent from this that in order for there to be motion, there must be things which can be moved by motion. For there cannot be act without a subject of act. Thus from the definition of motion it is clear that there must be a mobile subject in order for there to be motion.

             But even apart from the definition of motion this is apparent in itself, as is clear from the common opinion of all men. For everyone admits that a thing is not moved unless it can be moved. This applies to every motion, for a thing is not altered unless it is alterable, and a thing is not changed in place unless it is mutable in respect to place.

             And since a subject is naturally prior to that which is in the subject, we can conclude in regard to individual mutations, both from the standpoint of the mobile object and the mover, that a subject is burnable before it is burned, and a subject is a combustive, that is, able to burn, before it burns. I say 'before', not always in time, but in nature.

             973. From this proof of Aristotle Averroes takes the opportunity of speaking contrary to what we hold about creation according to faith.

             To come to be is to be changed in some way. Moreover, every mutation requires a subject, as Aristotle proves here. Hence it is necessary that everything which comes to be, comes to be from some subject. Therefore, it is impossible for a thing to come to be from nothing.

             He adds to this a second argument. When it is said that black comes to be from white, this is not said to occur per se such that the white itself is converted into black. Rather this is said to occur per accidens because black takes the place of the receding white. Whatever is per accidens, however, is reduced to that which is per se. Moreover, that from which a thing comes to be per se is the subject, which enters into the substance of the thing made. Everything, therefore, which is said to come to be from its opposite comes to be from that opposite per accidens, but from the subject per se. It is not possible, therefore, for being to come to be from absolute non-being.

             Thirdly, he adds to this the common opinion of all of the ancient physicists who hold that nothing comes to be from nothing.

             Moreover, he gives two reasons why he thinks that the position that something comes to be from nothing has arisen.

             The first is that the common man thinks that only those things exist which can be perceived by vision. Therefore, since the common man sees that something has been made visible which was not visible before, he thinks that it is possible for something to come to be from nothing.

             The second reason is that the common man thinks that an agent needs matter in order to act because its power is diminished. This, however, is not due to the agent's lack of power, but to the very nature [ratio] of motion. Since, therefore, the first agent does not possess a power which is deficient in any way, it follows that this agent may act without a subject.

             974. But if one thinks correctly, he would realize that Averroes has been deceived for a similar reason--the same one which is thought to have deceived us, namely, the consideration of particular beings.

             For it is clear that the active potency of a particular agent presupposes a matter which a more universal agent makes, for example, an artist uses the matter which nature provides. Therefore, from the fact that every particular agent presupposes a matter which it does not make, it is not necessary to think that the first universal agent, which is the active power of the whole of being, presupposes something which, as it were, is not caused by it.

             Moreover, this does not agree with Aristotle's intention. For he proves in Metaphysics, II, that that which is most true and most being is the cause of being for all existing things. Hence it follows that the very being in potency which primary matter has is derived from the first principle of being, which is the most being. Therefore, it is not necessary to presuppose something for its action which has not been produced by it.

             And since every motion requires a subject, which Aristotle here proves and which is true, it follows that the universal production of being by God is neither motion nor mutation, but a certain simple emanation. And so 'to become' and 'to make' are used equivocally in reference to this universal production of things and in reference to other productions.

             Therefore, if we were to think that the production of things by God is from eternity, as Aristotle and many Platonists held, it is not necessary, in fact it is impossible, that some non-produced subject be understood for this universal production. Moreover, if we hold according to the judgment of our faith that God did not produce things from eternity, but that He produced them after they were not, it is not necessary to posit some subject for this universal production.

             It is clear, therefore, that what Aristotle proves here, namely, that every motion requires a mobile subject, is not contrary to the judgment of our faith. For it was said that the universal production of things, whether from eternity or not, is neither a motion nor a mutation. Motion or mutation requires that a thing be otherwise now than it was before, and so the thing would be previously existing. Consequently we are not now talking about the universal production of things.

             975. Similarly, when he says that a thing is said to come to be from its opposite per accidens and from its subject per se, this is true of particular productions, according to which this or that being comes to be, for example, a man or a dog. However, this is not true of the universal production of being.

             This is clear from what the Philosopher has said in Physics, I. For he said there that if this animal comes to be insofar as it is this animal, it is not necessary that it comes to be from 'non-animal' but from 'this non-animal'. For example, man comes to be from non-man, or horse from non-horse. But if animal as animal comes to be, it must come to be from non-animal. If, therefore, some particular being comes to be, it does not come to be from absolute non-being. But if the whole of being comes to be, that is, if being as being comes to be, it must come to be from absolute non-being, if it can be said that it 'comes to be' (for 'comes to be' is used equivocally, as was said .

             What he introduces concerning the opinions of the ancient philosophers is not applicable. For the ancient natural philosophers were unable to arrive at the first cause of the whole of being. Rather they considered the causes of particular mutations.

             The first of them considered the causes only of accidental mutation, holding that everything which comes to be is altered. The next ones arrived at an understanding of substantial changes. The last ones, as Plato and Aristotle, came to a knowledge of the principle of the whole of being.

             Therefore, it is clear that we are not moved to hold that something comes to be from nothing because we think that only visible things exist. Rather, on the contrary, we hold this because we do not consider only particular productions from particular causes, but the universal production of the whole of being from the first principle of being. Neither do we hold that a diminished power needs matter in order to act, as if it were deficient in natural power. Rather we say that this pertains to a particular power which does not have power over the whole of being, but which causes some being.

             And so it can be said that a diminished power makes something from something, just as we might say that a particular power is less than a universal power.

             976. Next where he says, 'Moreover, these things also . . .' (251 a 17), having shown that motion requires a mobile object and a motive power, he argues as follows.

             If motion has not always existed, one must say either that mobile objects and motive powers were made at some time before which they were not, or else they are eternal. Therefore, if it is said that every mobile object has been made, one must say that before the mutation which is taken as the first, there was another mutation and motion, according to which was made the mobile object itself which can be moved and was moved. This inference depends on what has gone before. If it is granted that motion has not always existed, but rather there is some first mutation before which there was none, then it will follow that that first mutation had some mobile object, and that this mobile object was made, before which it was not. For it was granted that all mobile objects have been made. Everything which comes to be, before which it was not, comes to be through some motion or mutation. Moreover, the motion or mutation by which the mobile object comes to be is prior to the mutation by which the mobile object is moved. Therefore, before the mutation which was said to be first, there is another mutation, and so on to infinity.

             If, however, it is said that mobile objects were always pre-existing, even though no motion existed, this seems to be irrational and the words of those who are unlearned. For it is immediately apparent that if there are mobile objects, there must be motion. For natural mobile objects and movers exist together, as is clear from Book III. And when movers and natural mobile objects exist, there must be motion.

             But in order to proceed more profoundly in search of the truth, we should say that this same thing must happen even if it is granted that movers and mobile objects always pre-exist before motion. This follows if it is granted that these have been made, that is, if prior to the mutation which is given as first, there was another mutation to infinity. This is clear as follows. Let it be granted that there are mobile objects and movers, and at some time the first mover began to move and something was moved by it, and before this nothing was moved, but there was rest. It is then necessary to say that another mutation occurred earlier in the mover or mobile object which the first mover begins to move. This is clear as follows.

             Rest is the privation of motion. Privation, however, is not in that which is receptive of a habit or form except through some cause. There was, therefore, some cause either on the part of the mover or on the part of the mobile object which was the cause of rest. Therefore, while it endured, there was always rest. If, therefore, at some time the mover begins to move, this cause of rest must be removed. But it cannot be removed except through some motion or mutation. Therefore, it follows that before the mutation which was said to be first, there was another earlier mutation by which the cause of rest was removed.

             977. Next where he says, 'For some things cause motion . . .' (251 a 29), he proves the necessity of the preceding argument.

             One might say that it happens that a thing is at one time at rest and at another time in motion without any pre-existing cause of rest being removed. Hence he wishes to reject this.

             Concerning this he makes two points. First he sets forth a certain thing which is necessary for his position. Secondly, where he says, 'But at any rate . . .' (251 b 1), he proves his position.

             He says, therefore, first that some movers move singly, that is, in only one way, and others move in respect to contrary motions.

             Things which move in only one way are natural. For example, fire always heats and never causes coldness. But intelligent agents move according to contrary motions, for contraries seem to be treated in one science. For example, medicine is the science of health and sickness. Hence it seems that a doctor by his own knowledge is able to move according to contrary motions.

             He makes this distinction of movers because in regard to things which act through intelligence what he has said does not seem to be true, that is, it does not seem to be true that if a thing is moved after it was at rest, then the cause of that rest must first be removed.

             For intelligent agents seem to be related to opposites without any mutation occurring in themselves. Hence it seems that they can move and not move without any mutation.

             Therefore, lest this destroy his argument, he adds that his argument holds in a similar fashion for things which act through intellect and for things which act through nature.

             Things which act through nature always move per se to one thing, but sometimes they move to the contrary per accidens. And for this accident to occur, there must be some mutation. For example, a cold thing always makes cold per se, but per accidens it heats.

             It heats per accidens when it is changed in some way, either insofar as it is turned to another site so that it is related in another way to that which it now makes hot and which it previously made cold, or else insofar as it disappears entirely. For we say that the disappearance of cold causes heat just as a helmsman by his absence causes the sinking of a ship. In a similar way cold becomes the per accidens cause of heat either by a greater withdrawal or a greater nearness, just as in winter the inner parts of animals are warmer as the warmth withdraws farther inside because of the encompassing cold.

             And the same applies to intelligent agents. For although there is one science of contraries, nevertheless there is not equal science of both. Rather it is principally of one. For example, medicine is ordained per se to produce health. If, therefore, it happens that a doctor uses his knowledge to induce illness, this will not be through his knowledge per se but per accidens, because of something else. And in order for that other to occur which before was not, some mutation is necessary.

             978. Next where he says, 'But at any rate . . .' (251 b 1), he introduces the proof of his position.

             He says, therefore, that since agents which act through nature and agents which act through intelligence are thus related in a similar way, we can say universally that whatever has the potency to do or to suffer or to move or to be moved cannot move or be moved in every disposition in which it is found. Rather this occurs insofar as such things exist in some determinate state and nearness to each other.

             And he concludes this from the foregoing. For it has already been said that in both natural agents and voluntary agents there is not one cause of diverse things unless this cause exists in some other disposition. Therefore, whenever a mover and the moved approach each other with a suitable nearness, and likewise when they are in whatever disposition is required so that one moves and the other is moved, then the one must be moved and the other must move.

             If, therefore, there has not always been motion, then it is clear that they did not exist in such a relation that one moves and the other is moved. Rather they existed in such a way that it was not possible for them to move and be moved. Afterwards, however, they do exist in such a relation that one moves and the other is moved. Therefore, one of them must have been changed.

             In all things which are called relations we see that a new relation occurs only through a mutation of one or the other. For example, if a thing which before was not double is now made double, then if one of the extremes is not changed, at least the other must be changed. And so, if a new relation should occur so that one thing moves and another is moved, one or the other must be moved first. Hence it follows that there is a certain mutation which is prior to the mutation which was said to be first.

             979. Next where he says, 'Further, how can there be . . .' (251 b 10), he proves his position with an argument taken from time.

             First he sets forth two things which are necessary for the following proof.

             The first is that there cannot be a before and after unless there is time. For time is nothing other than the before and after according to which things are numbered.

             The second is that there cannot be time unless there is motion. This is clear from the definition of time which he gave above in Book IV, saying that time is the number of motion in respect to before or after.

             980. Secondly, where he says, 'If, then, time . . .' (251 b 11), he comes to a conditional conclusion from what was said in Book IV.

             For he stated there, according to his opinion, that time is the number of motion. In the same place he said that other philosophers have held that time is a certain motion.

             Whichever of these may be true, it follows that this condition is true: if time is eternal, then motion must be eternal.

             981. Thirdly, where he says, 'But so far as time . . .' (251 b 13), he proves the antecedent of the above condition in two ways.

             He does this first by means of the opinions of others. He says that all philosophers except one, namely Plato, seem to agree that time is ungenerated, that is, time did not begin to be after it previously was not. Hence even Democritus proves that it is impossible for all things to have been made as if they began anew, because it is impossible for time to have been so made that it began anew.

             Only Plato 'generates time', that is, only he says that time was made anew. For Plato says that time was made together with the heavens. And he held that the heavens 'were made', that is, they have a beginning of duration, as Aristotle here imputes to him, according to which his words seem to sound superficial. The Platonists, however, say that Plato said that the heavens were made in the sense that they have an active principle of their being but not in the sense that they have a beginning of duration. Therefore, Plato alone seems to have understood that there is no time without motion. For he did not hold that time existed before the motion of the heavens.

             982. Secondly, where he says, 'Now since time . . .' (251 b 19), he proves the same thing through reason. It is impossible to say or to think that there is time without the 'now', just as it is impossible for a line to exist without a point. Moreover, the 'now' is a certain intermediate, having such a nature [ratio] that it is both a beginning and an end, that is, the beginning of the future and the end of the past. From this it seems that time must be eternal. For whatever time is taken, its extreme on either side is a 'now'. This is clear because no part of time is in act except the 'now'. For what has passed has already gone, and what is future as yet is not. Moreover, the 'now' which is taken as the extremity of time is a beginning and an end, as was said. Therefore, on either side of any given time there must always be time. Otherwise the first 'now' would not be an end, and the last 'now' would not be a beginning.

             From the statement that time is eternal, he concludes that motion must be eternal. And he gives the reason for this conclusion. Time is a certain property of motion, for it is its number, as was said.

             983. It seems, however, that Aristotle's argument is not effective. For the 'now' is related to time as a point is related to a line, as was explained in Book VI. But the nature [ratio] of a point is not such that it is a middle. Rather there is a point which is only the beginning of a line and another point which is only an end. It would happen, however, that every point is a beginning and an end insofar as it is a part of an infinite line. It cannot be proven, therefore, that a line is infinite because every point is a beginning and an end. Rather, conversely, from the fact that a line is infinite, it can be proven that every point is a beginning and an end. Therefore, if it seems that every 'now' is a beginning and an end, this is not true unless it is granted that time is eternal. It seems, therefore, that in assuming this, Aristotle presupposes the eternity of time, which he ought to prove.

             Averroes, however, wishing to save Aristotle's argument, says that the 'now' is always a beginning and an end insofar as time does not stand still, as does a line, but rather is in flux.

             This clearly is not at all pertinent. For from the fact that time is flowing and not standing still, it follows that one 'now' cannot be taken twice as one point can be taken twice. But the flux of time has no bearing on the 'now' being both a beginning and an end. For the same nature [ratio] is found in the inception and termination of every continuum, whether permanent or in flux, as is clear from Book VI.

             984. Therefore, we should re-interpret Aristotle's statement that every 'now' is a beginning and an end, which he wishes to derive from what he assumed first, namely, that there is no before and after unless there is time. He uses this assumed principle only to conclude that every 'now' is a beginning and an end. Let it be granted that some 'now' is the beginning of some time. It is clear, moreover, from the definition of 'beginning' that the beginning of time is that before which no time exists. Therefore, there is something 'before' or 'earlier' than this 'now' which was given as the beginning of time. But there is no before without time. Therefore, the 'now' which was given as the beginning of time is also an end of time. And in the same way, if a 'now' is an end of time, it follows that it is also a beginning, because it is the nature [ratio] of an end that after it there is nothing of it. But there is no after without time. It follows, therefore, that the 'now' which is an end is also a beginning of time.

             985. Next where he says, 'The same reasoning . . .' (251 b 29), he shows that there will always be motion.

             He proves this from motion. The argument given above which was taken from motion concluded only that motion never began. But the argument taken from time concluded both that motion never began and that it will never cease.

             He says, therefore, that the same argument which proves that motion never began can also be used to prove that motion is incorruptible, that is, that motion will never cease. For just as it follows, if there is a beginning of motion, that there was some mutation prior to the mutation given as first, so if it is held that motion at some time ceases, it will follow that there will be some mutation after the mutation which was given as last.

             He explains how this follows by abridging what he has said more fully above about the beginning of motion. For he said that if motion begins, mobile objects and movers either began or always were. And a similar distinction can be made here, because if motion ceases, mobile objects and movers will remain or they will not. And since he has shown above that the same thing follows in either case, here he uses only the second way, namely, if it is granted that motion ceases, then mobile objects and movers will cease.

             On this supposition he says that the actual motion and the mobile object do not cease at the same time. Rather, just as the generation of the mobile object is prior to its motion, so the corruption of the mobile object will be later than the cessation of its motion. And this is clear because it happens that a burnable object remains after the burning stops.

             And the same thing may be said of the mover as was said of the mobile object. For the moving being in act and the moving being in potency do not stop together. Thus it is clear that if the mobile object itself is corrupted after the cessation of motion, then there must be a corruption of that mobile object.

             Moreover, since it was granted that all movers and moved objects cease, then the thing which corrupts will necessarily be corrupted at a later time. And since corruption is a mutation, it follows that there are mutations after the last mutation. Since, therefore, this is impossible, it follows that motion endures forever.

             986. These, then, are the arguments by which Aristotle intends to prove that motion always was and never ceases.

             One part of his position, namely, that there was always motion, conflicts with our faith. For according to our faith nothing has always existed except God alone, Who is altogether immobile, unless one wishes to say that motion is divine understanding. But this meaning of motion is equivocal. For Aristotle does not here mean motion of this kind, but motion in its proper sense.

             But the other part of his position is not altogether contrary to faith. For as was said above, Aristotle is not treating the motion of the heavens, but motion in general. But according to our faith we hold that the substance of the world at some time began to be but it will never cease to be. We hold also that some motions will always be, especially in men, who will always remain, living an uncorruptible life, either damned or blessed.

             Indeed some, attempting in vain to show that Aristotle has not spoken contrary to faith, have said that Aristotle does not intend here to prove as a truth that motion is eternal, but to introduce arguments on both sides, as if for a point in doubt. But because of his method of procedure this appears to be nonsense. And besides, he uses the eternity of time and of motion as a principle to prove the existence of a first principle, both here in Book VIII and in Metaphysics, XII. Therefore it is clear that he assumes this as proven.

             987. But if one correctly considers the arguments given here, the truth of faith cannot effectively be opposed to such arguments.

             For arguments of this kind are effective in proving that motion did not begin by way of nature, as some have held. But it cannot be proven with these arguments that motion did not begin in the sense that things were produced anew by the first principle of things, as our faith holds. This is clear to one who considers the individual inferences which are given here.

             For when one asks whether or not movers and mobile objects have always existed if there has not always been motion, one must answer that the first mover has always existed. All other things, whether they be movers or mobile objects, have not always existed but began to be from the universal cause of the whole of being. It was shown above, moreover, that the production of the whole of being by the first cause of being is not a motion, whether or not it is granted that this emanation of things is from eternity.

             Thus, therefore, it does not follow that before the first mutation there is another mutation. However, this would follow if movers and mobile objects were newly produced in being by some particular agent which acts on some presupposed subject which is changed from non-being to being, or from privation to form. Aristotle's argument deals with this type of beginning.

             988. But since we hold that at least the first mover has always existed, we still need to give an answer to his next deduction, in which he concludes that if motion begins to be anew when movers and mobile objects pre-exist, then movers and mobile objects must not previously have been in that disposition in which they are while there is motion. And thus some mutation must precede the first mutation.

             If we speak about motion itself, the answer is easy. Mobile objects were not previously in the disposition in which they now are, because previously they did not exist. Hence they could not be moved. And as was said, existence is not acquired through a mutation or a motion, but through an emanation from the first principle of things. Thus it does not follow that there was a mutation before the first mutation.

             But there remains a further question about the first production of things. If the first principle, which is God, is not related differently now than He was before, He does not produce things now rather than before. And if He were related differently, at least a mutation on His part will be prior to the mutation which is first.

             Now if He were an agent only through nature, and not through will and intellect, this argument would conclude with necessity. But because He acts through His will, He is able through His eternal will to produce an effect which is not eternal, just as through His eternal intellect He can understand a thing which is not eternal. For a known thing is in a certain way the principle of action in agents who act through the will, just as a natural form is the principle of action in agents who act through nature.

             989. Let us pursue this further. We do not see that the will puts off doing what it wishes unless something is expected in the future which does not yet exist in the present. For example, I do not wish to make a fire now but later in the future when 1 expect cold, which is the reason why I make the fire; or at least it is expected at the present time. Moreover, since time succeeds time, this cannot occur without motion. Therefore, a will, even if it is immutable, cannot put off doing what it wills except by some intervening motion. And so it is not possible for a new production of things to proceed from an eternal will unless intermediate motions succeed each other to infinity.

             But such objectors do not see that this objection proceeds from an agent in time, that is, from an agent who acts in a presupposed time. For in an action of this kind which occurs in time, one must consider some determinate relation to this time or to those things which are in this time, so that it occurs at this time rather than at the other. But this argument has no application to a universal agent which produces even time itself together with the rest of things.

             For when we say that things were not eternally produced by God, we do not mean that an infinite time has preceded in which God ceased from acting, and that after a determined time He began to act. Rather we mean that God produced time and things together in being after they were not. And so we need not consider that the divine will willed to make things not then, but afterwards, as if time already existed. Rather we need only consider that He willed that things and the time of their duration should begin to be after they were not.

             If, however, one asks why He willed this, without doubt it must be said that He did this for His own sake. For just as He made things for His own sake so that a likeness of His goodness would be manifested in them, so He wills them not always to be so that His sufficiency would be manifested in this, that when all other things do not exist, He has within Himself every sufficiency of beatitude and of power for the production of things.

             This indeed may be said insofar as human reason can understand divine things. Nevertheless, the secrets of divine wisdom, which cannot be comprehended by us, are preserved.

             990. Since, therefore, the answer to this argument proceeds from the supposition that there has not always been time, it remains to answer the argument through which it seems to be shown that there was always time. Aristotle perhaps gives the argument concerning time after the argument concerning motion because he thought that the preceding argument concerning motion was not effective unless it is granted that time is eternal. Therefore he says that whenever there is time, it must be admitted unhesitatingly that there is a 'now'. That every 'now', however, is a beginning and an end of time cannot be conceded unless it is also granted that there has always been motion such that every indivisible that is taken in motion, which is called an 'impulse', is a beginning and an end of motion. For 'now' is related to 'impulse' as time is related to motion. If, therefore, we hold that there has not always been motion but that there is a first indivisible in motion before which there was no motion, then there will also be a 'now' in time before which there was no time.

             We have already shown above, in explaining the text, that what Averroes says in confirmation of this argument is not effective.

             And Aristotle's position that there is no before and after without time is also not effective.

             For when we say that the beginning of time is that before which none of it is, it cannot be said on account of this that the 'now' which is the beginning of time is preceded by a time which is signified by 'before'. In the same way if in regard to magnitude I say that the beginning of a magnitude is that outside of which none of it is, it cannot be said that 'outside of that beginning' signifies a place existing in nature, but only an imaginary place. Otherwise one could posit a place outside the heavens whose magnitude is finite, having a beginning and an end.

             In a similar way the first 'now' which is the beginning of time is not preceded by a time existing in nature, but only in our imagination. And this is the time which is designated when it is said that the first 'now' is a beginning of time 'before' which there is no time.

             Or it can be said that when the beginning of time is said to be that before which there is no time, the word 'before' does not remain affirmative, but becomes negative. Thus it is not necessary to posit a time before the beginning of time. With respect to things which are in time, it happens that some time pre-existed their beginning. For example, when it is said that the beginning of youth is that before which there is no youth, it is possible to understand the 'before' affirmatively, because youth is measured by time. Time, however, is not measured by time. Hence time did not pre-exist its beginning. And so the word 'before', which is used in the definition of the beginning of time, cannot remain affirmative, but becomes negative.

             There is, however, a duration before time, namely, the eternity of God, which has no extension of either before or after, as does time, but is a simultaneous whole. This does not have the same nature [ratio] as time, just as divine magnitude is not the same as corporeal magnitude.

             Thus when we say that outside the world nothing exists except God, we do not posit any dimension outside the world. In the same way when we say that before the world nothing was, we do not posit a successive duration before the world.