To What Extent Does Time Depend Upon the Soul?

The relationship between time and the soul (or mind/intellection) seems to be one of complete dependence. In other words, Aristotle clearly indicates that if there is no soul, there is no time. Hussey translates this passage by declaring, “‘If there were no soul’ must be understood as ‘if the universe were such that it was impossible for there ever to be any soul in it’ - as appears from the next sentence: ‘if it is impossible that there should be something to do the counting.’”[1]

If this is the case, then the relationship between time and the soul is not one of complete dependence, since other works of Aristotle[2] seem to indicate that the ‘substrates’ exist without being perceived. Hussey details this idea by declaring, “All but the Topics passage refer to the case of sense perception. The primary objects of sense-perception, the ‘sensibles’ (aisthêta) such as colours and tastes, have no existence independently of perception.” Hussey continues this line of thought by declaring, “whereas the ‘substrate’, i.e. the material bodies which are called ‘perceptible by sense’ derivatively, do so exist. So there is a sense in which ‘something sense-perceptible’ could exist even if there were no perceivers (Categories 7) and a sense in which this is false (Metaphysics IV. 5, de Anima III.2).”[3] Hussey introduces a very good point here, for Aristotle declares that the ‘now’ of time is the same in the substratum since motion goes with magnitude, and time goes with motion. (219b 13-16). However, how this squares with Aristotle’s definitive remark that time requires a soul still seems to remain unsettled. Thus, the second question, ‘can there be time without a soul?’, may provide further help with the question, ‘to what extent does time depend upon the soul?’

Can There be Time Without a Soul?

In his book Aristotle: A Complete Exposition of His Work and Thought, W. D. Ross delineates, “Aristotle raises, without very definitely answering, an important question when he asks whether there would be time if there were not soul. It might be urged, he points out, that if there were no one to count there would be nothing that could be counted, and therefore no number.” Ross goes on to conclude, “All that could then exist would be not time but its substratum movement; i.e. there would still be movement, but it would have no measurable aspect.”[4]

While Ross’ conclusion, prima facie, seems to indicate that there could possibly be time without a perceiver, it also seems to be wrought with other difficulties and merely raises more questions. For instance, what is movement that has no measurable aspect? Moreover, it seems that the measurable aspect of movement would be the very thing that might be needed in order to indicate that there was movement occurring. In other words, it seems that movement could not be movement without measurability. However, measurability seems to rely upon some sentient mind to measure. And thus we are back to Aristotle’s conclusion that time is mind dependent.

In his commentary to Aristotle’s Physics Ross repudiates Aristotle’s statement that time is dependent upon the soul. Conen, responding to Ross’ repudiation declares,

What reason does Ross advance for his repudiation of Aristotle’s statement that time depends upon the soul? Aristotle is wrong, says Ross, because motion exists independently of the soul and it is “obvious” that motion cannot exist if time does not exist. Just what makes this fact obvious Ross does not say. Is it Aristotle’s definition of motion? But there does not seem to be anything in “the act of a being in potency in so far as it is in potency” that implies time as a prerequisite, or which suggests an “obvious” deduction to this fact. Perhaps, then, something in experience makes it obvious. But Aristotle’s whole analysis of experience has gone to show that, far from being a prerequisite of motion, time is rather a consequent of motion, and this, only with respect to the numbering soul. Time is not, as Ross would have it, a sine qua non of motion, somewhat as space would be bodies. It is rather motion that is a sine qua non of time, as is also a numbering soul. [5]

The observations made by Conen can not be ignored. It seems a rather difficult task to support a declaration that time could exist without a soul. And once again we are back to Aristotle’s conclusion that time is mind dependent.

In keeping with the current question, Hussey brings to his reader’s attention this particular idea. Hussey declares, “There are two kinds of ‘coutables’ viz. The concrete totalities and the abstract numbers. If there were no soul, the abstract could not exist, since they are created by the mental operation of abstraction. The concrete totalities would still exist but would not be countable.”[6] Essentially Hussey seems to be saying the same thing Ross said at footnote 47. Moreover, Hussey’s comments seem to strengthen the idea that Aristotle has, in fact, an idealist view of time. Since, if the concrete totalities were not countable, and the concrete totalities are the things which a mind perceives (and thus counts), and if what Aristotle declares is true, that if there is not someone to count there cannot be anything that can be counted, then to say concrete totalities would exist but not be counted is a contradiction. Besides, in Aristotle’s view of time, we apprehend time only when we have marked movement (before and after), and this is done in the two ways which Hussey put forth above, namely the abstract and the concrete. The abstract is counted when motion is not perceived because there is still motion in the mind via thought. And of course, the concrete is counted because the movement is actually perceived and marked (before and after), as Aristotle declared.

Lastly, in answering this question, Aquinas concludes that “time does not have a perfect existence outside of the soul.”[7] He comes to this conclusion based on his response to the notion that time does not exist because it is composed of non-existent parts (i.e. time as an attribute).
Aquinas details his conclusions by declaring,

He [Aristotle] says that, if there is no soul, one must say either that time does not exist, or, more correctly, that without soul time is some kind of a being—if, for example, it happens that there is motion but no soul. For if there is motion, it is necessary that there is also time. For before and after are in motion, and the before and after of motion, insofar as they are numerable, are time. To understand this answer it must be realized that, if there are numbered things, then there must be number. Hence, both numbered things and their number depend on one who numbers. Now the existence of numbered things does not depend on an intellect which is the cause of the things, as is the divine intellect. However, their existence does not depend on the intellect of the soul. Only numeration itself, which is an act of the soul, depends on the intellect of the soul. Therefore, there can be sensible things when no sense power exists, likewise there can be number and numerable things when no one who numbers exists.

But perhaps the conditional proposition which he gave first is true; that is, if it is impossible for their to be someone who numbers, then it is impossible for their to be anything numerable. This is similar to the following true proposition: if it is impossible for there to be someone who senses, then it is impossible for their to be something sensible. For if there is something sensible it can be sense. And if it can sensed then there can something which senses.
. . . In the same it follows that, if there is something numerable, then there can be something which numbers. Hence, if it is impossible for there to be something which numbers, then it is impossible for there to be something numerable. But it does not follow that, if there is no one who numbers, then there is nothing numerable, as the Philosopher’s objection proceeds. . . . Nor is anything concerning motion actually found in things except a certain indivisible part of motion, which is a division of motion. But the totality of motion is established by a consideration of the soul which compares a prior disposition of the mobile objects to a later one. Therefore, time also does not have existence outside the soul in respect to its own indivisible part. For the totality of time is established by the ordering of the soul which numbers the before and after in motion, as was said above. Therefore the Philosopher significantly says that, if soul does not exist, then time is “some kind” of being, that is, an imperfect being. In the same way, if there happens to be motion but no soul, motion is also said to be imperfect. [8]

Aquinas seems to conclude above that without the soul time is some type of imperfect being. Which is also the case for motion, in that if there is no soul to perceive the motion the motion is imperfect. However, it seems that Aquinas would have to concede that this could never be the case granting the divine intellect[9], and thus there would always be at least one perceiver who sees the motion and does the counting. Once again we are back to Aristotle’s original claim that time is mind dependent.

[1] Hussey, 172.
[2] Categories 7, 7b 33-8a 6; Topics V.9, 138 b 30-37; Metaphysics IV.5, 1010b 30 - 1011a 2; de Anima III.2, 426a 15-26. These references were taken from Hussey’s commentary to Aristotle’s Physics, 173.
[3] Hussey, 173.
[4] W. D. Ross, Aristotle: A complete Exposition of His Works and Thought, (New York: Meridian Books, 1959), 92.
[5] Conen, 457.
[6] Hussey, 173.
[7] Aquinas, 307.
[8] Aquinas, 306-07.
[9] This idea, of course, is a discussion that could entail a paper in and of itself. See Aquinas commentary to the Physics as well as Commentary on Sentences.

Time as Mind Dependent

Aristotle, at 223a 16-27, seems to quite clearly communicate that without a counter (i.e. a soul) there cannot be anything that can be counted. Moreover, if there cannot be anything that can be counted, there can be no time. Quoted directly Aristotle declares, “for if there cannot be some one to count there cannot be anything that can be counted either, so that evidently there cannot be number; for number is either what has been, or what can be, counted. But if nothing but soul, or in soul reason, is qualified to count, it is impossible for there to be time unless there is soul.”[1] Thus, time is dependent upon a counter (or soul).

Aquinas comments on these passages by declaring,

If it is impossible for there to be something which can be numbered, then it is impossible for there to be something numerable, that is, able to be numbered. But if the numerable is not, number is not. For number exists only in that which is actually numbered or in that which is potentially numerable. Therefore, it follows that, if something which is able to number does not exist, then number does not exist. But nothing can number except the soul, and among the parts of the soul nothing except the intellect. For to number is to relate numbered things to one first measure, and this is done by reason [ratio]. Therefore, if no intellective soul exists, there is no number. But time is a number, as was said. Therefore, if no intellective soul exists, there is no time. [2]

This account of time and number seem to clearly indicate that Aristotle is an idealist in reference to his views on time. However, before a definite conclusion can be drawn a closer look at these passages is needed.

Regarding Aristotle’s definition of time as number, time is not only a measure but it has some type of relation to the soul. This is so because Aristotle declares that only a mind can count. Conen points out, “Since time is number, and only soul can number, it would follow that the relation of time to the soul is one of dependence.”[3] On the other hand, Callahan declares, “Asking what time would be if there could be no soul to number motion is somewhat irrelevant to the present analysis, and Aristotle passes over it lightly.”[4] Perhaps Callahan is correct. Perhaps, this issue is irrelevant. However, it seems quite erroneous on the part of Callahan to dismiss this issue on the basis that “Aristotle passes it over lightly.”

It would seem more advantageous to Aristotle’s whole treatise on time, if this particular issue were indeed irrelevant, to ignore it altogether. The fact that Aristotle discusses it warrants a closer examination. Moreover, Conen seems to think is very important because “For Aristotle introduces the soul only in so far as it is necessary to a fuller and more exact understanding of time as it exists in nature itself.”[5] Therefore, to what extent does time depend upon the soul? Can there be time without a soul? Is, in fact, Aristotle an idealist with regard to time? All these questions must be examined in turn in order to draw a viable conclusion to the final question.

[1] 223a 23-26.
[2] Aquinas, Commentary on Aristotle’s Physics, 306.
[3] Conen, 451.
[4] Callahan, 76.
[5] Conen, 452.

Movement, Change and Number: Aristotle’s View of Time

Number, Potentiality and Actuality as they Relate to Time (Part 2)


For Aristotle motions (or change) have countability in that they can actually be counted as they occur and they have the potential to be counted. Aristotle declares that we “apprehend time only when we have marked motion, marking it by before and after, and it is only when we perceive before and after in motion that we say that time has elapsed. Now we mark them by judging that one thing is different from another, and that some third thing is intermediate to them.” [1] This third thing which is intermediate to before and after is the now. Thus, there is an asymmetry of potentiality and actuality in enumerable motion.

If the two ‘nows’ were perceived, which occurred before and after the unnoticed interval, then according to Aristotle the two ‘nows’ have been marked and a connection has been made between the ‘before’ and ‘after’ of the unnoticed interval. This is best illustrated by the train once again. The perceiver marked a connection between the ‘before’ and ‘after’ of the unnoticed interval (the train passing while the perceiver was asleep) in that the train was no longer there when the perceiver awoke. The perceiver would surmise that time had passed (based on change between moments of ‘before’ sleep with the train in motion and ‘after’ sleep with the realization that the train had passed—changed had occurred) because of the absence of the train which was there when the perceiver fell asleep. Hussey elaborates on this by declaring, “We think that some time has elapsed, between the two ‘nows’, if and only if we have some means of distinguishing the two ‘nows’, and this we have if and only if we perceive that a change has taken place between them. To perceive this is to mark off the change by means of the ‘nows’ which bound it (elaborated at 219 a 22-30).” [2] All this complication of enumeration of motion, the nonexistence of the past, and the now seems to raise several problems for which Aristotle has been criticized in the past.

First, time is viewed as a continuum and Aristotle’s view of the ‘now’ seems to be discrete. [3] Von Leyden hints that in terms of number Aristotle’s view is discrete. Von Leyden points out that “Aristotle himself was aware [due to a passage from De Anima I. 3, 407 a 6-10] of the fact that thoughts, being like integers, do not correspond to the organization of undivided continua such as time or motion.” Von Leyden continues by declaring, “The reason why he [Aristotle] nevertheless defined time as a number was that, if the before and after in movement are counted by successive nows, sections of a continuum are counted, of which time is the number counted, not that by which it is counted.” [4]

Secondly, if Aristotle in fact affirms that the parts of time (past and future) are non-existent, [5] then he must account for the tensed predication which is used in languages (including his own—Greek) which indicate past and future. In other words, there must be some sense in which the past and future are existent, if by no other means than logical abstraction through tensed predication. This criticism is not too weighty due to the aporetic nature of Aristotle’s views on the parts of time. Moreover, Richard Sorabji suggests that this apparent problem is easily solved. Sorabji declares,

I want to suggest two ways of solving this paradox, although only the first, I believe, gets to the heart of the matter. It does so by asking what is meant when we say that there is a past and a future, or that they exist. The author of the paradox may not have thought out what is meant, but the truth behind his paradox depends on the fact that ‘exist’ sometimes means ‘be present’, and that neither past nor future exists in this sense. Of course, when the point is spelt out in this way, the non-existence, the non-existence of past and future appears quite unremarkable, but, until it is spelt, the author of the paradox may well feel that his claim of non-existence is more significant. He is in any case still entitled to ask whether there is some other sense in which the past and future do exist, and this question puts an onus on us.


. . . Instead of merely saying ‘there was no universe in the past’, or ‘there will be no universe in the future’, he could ‘there is no past’, or ‘there is no future’. It is in contrast to this denial that we can see a sense for the claim that there is a future and a past; and not only does this claim turn out to have a sense, but it is, furthermore, a claim that any rational person ought to endorse. I believe, therefore, that this constitutes a solution to the paradox: it is only in the irrelevant sense being present that the past and future do not exist. In the sense that matters, there is a past and there is a future, and so there is time. [6]

Sorabji points out that since there is no one English equivalent of Aristotle’s ‘to be’ verb, it is more natural to say there is no past in English. Moreover, Sorabji points out that Aristotle moves in the right direction in Physics 3. 6, 206a 21-3, by recognizing “that a different sense of the verb ‘exist’ applies to temporal entities.” [7]

[1] 219a 22-26.
[2] Aristotle, Physics, trans. with commentary Edward Hussey, 142.
[3] This is a criticism pointed out in Von Leyden’s article “Time, Number, and Eternity, in Plato and Aristotle.” This criticism seems to be valid only if there is an absence of a perceiver between the two apparently disconnected ‘nows.’ Von Leyden is not forthcoming in his article about how Aristotle’s view is discrete.
[4] Von Leyden, 50.
[5] This criticism is conditional since Aristotle seems to be aporetic (a point which was brought to my attention by Dr. Owen Goldin via correspondence on November 9th, 2001) regarding the issue of the parts of time.
[6] Sorabji, 12.
[7] Ibid., 13.

Movement, Change and Number: Aristotle’s View of Time

Number, Potentiality and Actuality as they Relate to Time

In Physics book 4, chapter 11, it seems that Aristotle has yet to commit to any exact theory of time. Nonetheless, Aristotle asserts that time does not exist without change. Edward Hussey in his translation and commentary to Aristotle’s Physics points out that “Aristotle uses two claims about the perception of change and time: (a) when we do not perceive any change to have taken place, we do not think any time has elapsed; (b) when we do perceive change to have taken place, we do think some time has elapsed.”[1] Using an illustration of sleep (‘those who are fabled to sleep among the heroes in Sardinia’) Aristotle points out that the interval between the time ‘before’ sleep and the time ‘after’ is a type of connection between the prior ‘now’ and the posterior ‘now’ and the two are made one. The two are ‘made one’ in the sense that those who slept failed to consciously notice the interval between the two ‘nows.’

W. Von Leyden comments on this difficult passage by concluding, “The argument [of Aristotle’s that time is closely related to change] is significant in that the sufficient as well as necessary condition of any time-lapse is found to lie in the distinction of two ‘nows’ and a ‘before’ and ‘after’ in motion.”[2] Adding to Von Leyden’s comments, it seems this passage (218b 21-28) is at best an attempt by Aristotle to make sense of how time cannot exist without change and some perceiver of change. To illustrate this point, if a person were by a railroad track sitting on a bench and a very long train proceeded to pass by, the perceiver would be conscious of time’s passing via the movement of the train and the counting of the cars which pass. However, let us assume this is a very long train, and as it passes the perceiver falls asleep. Now let us assume that the train has completely passed the person who is asleep. Knowing the train was there ‘before’ the perceiver fell asleep, the perceiver would realize time had elapsed upon waking up from slumber since the train is no longer there ‘after’ the perceiver awakes. This is the connection Aristotle makes between the now of the ‘before’ and the now of the ‘after’ which is essentially perceived and counted by the perceiver upon awakening. And this is accomplished in that the perceiver understands change has occurred due to the train’s absence. In all this a perceiver is needed in order for the realization of motion and change to have occurred. Thus, time, in terms of ‘before’ and ‘after’ and Aristotle’s concept of the now needs a perceiver to be real.

Aristotle’s notion of the ‘now’ is quite intricate and complicated. Paul F. Conen describes Aristotle’s now as “The plurality of before and after in motion which time is, is a plurality of ‘nows.’ As a line is pluralized by the points actually numbered or numerable on it, so motion is pluralized by the ‘nows’ counted or countable in it.”[3] Thus, Conen understands Aristotle’s ‘now’ in time and motion as that which is numbered. This is in fact how Aristotle defines the ‘now.’[4] However, in relation to Aristotle’s puzzle of the parts of time, he concludes that time “is not held to be made up of ‘nows.’”[5] Therefore, if time is a kind of number, in respect of ‘before’ and ‘after,’ and motion is a perpetual succession (as Aristotle declares of both motion and time, 219b 5-13), and time is not independent of motion but is apart of motion in that it admits of enumeration, and the ‘now’ is a given present moment, then how is it that time is not held to be made up of ‘nows?’ Prima Facie this seems to be a strong discrepancy in Aristotle’s philosophy of time, albeit the possible aporetic nature of the assertions. However, even if this section is aporetic discrepancies are still evident and need to be accounted for in one way or another. Moreover, giving Aristotle the benefit of the doubt regarding these discrepancies, a more focused examination of the ‘now’ is needed.

In discussing the ‘now’ Aristotle claims that since motion is always different, time too is always different. The ‘before’ (prior) and ‘after’ (posterior) in time comes about because the same occurs in motion. There is a ‘before’ and ‘after’ in motion, and thus time follows suit. John Callahan helps elaborate on the concept of Aristotle’s ‘now’ by declaring, “Motion, which is the actualization of the potential, takes place in various stages that correspond to the magnitude which is traversed by the motion.” Callahan continues by declaring, “The motion does not exist with all its parts together; there is an order in the parts, and this order, insofar as it is made numerable by the now, is time.”[6] These comments are helpful in understanding the ‘now’ in several ways.

First, it helps us understand and consider time in terms of number through the ‘prior’ and ‘posterior.’ For example, going back to the train illustration. Considering the train itself, the cars are linked together as parts which make up a whole. The train is in motion and is thus countable when there is a perceiver to count the cars as they pass. Thus numbering is occurring in that the cars can be counted as they pass and in all this motion there is a ‘prior’ car which passes and becomes ‘posterior.’ The different events occurring in the train’s motion are the series of cars which pass at given points in the count.

Time may be “defined differently by the different events that are taking place in it.”[7] This is true even though Aristotle declares time, more specifically all of time that is simultaneous, is the same (219b 10-12). Second, when we consider the ‘now’ in the flow of time we discover that Aristotle thinks that in one sense it is the same, and in another sense it is different (219b 10-12). Here we see motion as the actualization of the potential, as Callahan described above.

Moreover, for Aristotle the number (or count) in motion is, in reality, fluid. Unlike Zeno’s paradox where a given two points, A to B, has a series of divisions which are infinite (i.e. A1, A2, A3 . . . ad infinitum), Aristotle denies that this can be the case. Thus, time is not composed of a series of ‘nows’ between the motion of something from point A to B. The motion would be fluid unless interrupted, but there would never be an infinite amount (or even a series) of ‘nows’ between point A and B. In other words, if an individual were to walk from one point to another (regardless of the distance), the act of the walker would be fluid and could not, in reality, be broken into divisible points from A to B. As a logical construct there are an infinite amount of points from A to B, but not in reality. In relation to time, Aristotle believes that the motion between time T1 and T2 is fluid, unless interrupted, and can never be divided into an infinite amount of points, or ‘nows.’ In Physics IV (219a 4-14) Aristotle argues the fluidity of magnitude, movement, and thus time in this way:

1) All Magnitude is continuous.
2) Movement goes with magnitude (thus movement is continuous).
3) Time is a part of movement.
4) Therefore, time is continuous.[8]

In making sense of the above complications regarding Aristotle’s ‘now,’ Conen uses Simplicius’ explanation to sort out the difficulties and provide a fair answer. Describing Simplicius’ solutions, Conen states,

There are three elements to Simplicius’ explanation: (1) He decides in precisely what sense the “now” is a unit of number. The “now” is a unit of number, he says, because a unit is that which makes an indivisible thing correspond to another indivisible, and the “now” is that which makes the indivisible subject of motion correspond to the indivisible phase of motion. (2) He decides in just what sense there is a similarity between the generation of number from a unit, and the generation of motion from the subject of motion and time from the “now.” The similarity lies in this, that just as a unit, taken again and again, results in number, so the subject of motion and the “now” taken again and again, result in motion and time. But (3) he immediately qualifies the last statement—and here is the heart of the explanation. He says that the “being taken again and again” as applied to the subject of change and to the “now”: the former is a discrete again and again, the latter is a continuous succession; the former results in a discrete number, the later in a continuum.[9]

Thus, we can see once again, how the ‘now’ in one sense is the same and in another sense it is different.

[1] Aristotle, Physics, trans. with commentary Edward Hussey (Oxford: Clarendon Press, 1983), 141.
[2] W. Von Leyden, “Time, Number, and Eternity in Plato and Aristotle,” The Philosophical Quarterly, 14 (January 1964), 48-49.
[3] Paul F. Conen, “Aristotle’s Definition of Time,” The New Scholasticism, XXVI (October 1952), 445.
[4] 219b 1-17, 372.
[5] 218a 7-8, 370.
[6] John F. Callahan, Four Views of Time in Ancient Philosophy (Cambridge: Harvard University Press, 1948), 53.
[7] Ibid.
[8] The original text is not in syllogistic form. I put this argument in syllogistic form to highlight Aristotle’s contention that time is fluid and not broken up into ‘nows.’. See also 220a 1- 24.
[9] Conen, 448.

Aristotle’s Definition of Time

In his attempt to make sense of the nature of time, Aristotle turns to several observable factors, namely, movement (or motion), change, and number. By number, Aristotle means observable sequence in terms of ‘before’ and ‘after.’ Of course, for Aristotle number is count which means that one could have a sequence without a measure or count. For example, there could be a sequence of things, which are static (without motion) and a count could be performed when considering this sequence. Moreover, the ‘before’ and ‘after’ in this type of sequence would be in the counting of the sequence and not the sequence itself. Thus, number and movement in Aristotle’s definition of time are, in a sense, similar, or have closely related functions[1]. As Aristotle himself declares, “for time is just this—number of motion in respect of ‘before’ and ‘after.’ Hence time is not movement, but only movement in so far as it admits of enumeration.”[2] Moreover, number is that which is counted or that which is countable and is also that which we count.[3]

Regarding movement Aristotle details that time itself is not movement (motion). However, time is not independent of movement.[4] Here, as J. T. Fraser points out, Aristotle is suggesting “that time is either identical with motion or it is something closely related to it.”[5] Additionally, Aristotle restricts motion to three kinds: qualitative, quantitative, and local.[6]
Aristotle describes qualitative motion as a change from black to white, or a change from cold to hot. Quantitative motion is a change in size. For example, an increase in measurement—one’s getting taller as they grow from childhood to adulthood. Local motion is change in place. This would be the most basic form of motion for Aristotle.

With regard to changes occurring between black and white, this is “ a process of whitening and change from cold to hot is a process of heating, and these can readily be understood quantitatively as rates of whitening and rates of heating. Now time is a quantifiable change from ‘before’ to ‘after.’[7] Thus, the conclusion is Aristotle’s famous definition of time as the number of motion in respect of ‘before’ and ‘after.’ Aristotle’s definition of time not only involves motion but change as well. Moreover, Aristotle’s use of kinesis (motion) is quite broad and encompasses all changes except substantial generation. In fact, Aristotle sees time as an aspect of not only motion but change. Philip Turetzky elaborates on this by declaring,

Aristotle thinks of time as an aspect of change, and things change from something to something else. Before and after are thus formal elements of change distinct from change, rather than part of its definition. The before and after of change comprise the initial and final states of a modification of some magnitude, not just spatial magnitudes. Since change can occur between qualitites, between places, as growth and diminution, and as creation and destruction, it advances from a prior state, before the change, to a posterior state, after the change. So Aristotle thinks that because “before” and “after” apply to magnitude they apply to change, and because they apply to change they apply to time. [8]

Moreover, Aristotle details that “we perceive movement [change] and time together.”[9] The operative term in this assertion is perceive. We perceive movement and time together in that time is dependent upon the mind. Aristotle illustrates this idea by declaring that if a person is in darkness and is thwarted from perceiving motion, the mind will still have motion in it via thought. This thought is movement in the mind and thus time has elapsed based on this internal movement. Here, Aristotle is clearly declaring that if movement is not perceived by the mind in physical things (due to darkness or some other thing thwarting a mind’s perception), time continues to lapse since there is movement which takes place in some mind by the enumeration of thought.

The fact that some time is thought to have passed denotes that some movement has occurred in the mind. Thus, our inability to perceive movement in physical things does not necessarily negate time’s persistence to elapse due to movement in our mind. Therefore, for Aristotle, time is not independent of movement. Aristotle supports this idea by declaring, “ time is either movement or something that belongs to movement. Since then it is not movement, it must be the other.”[10]

There is in this definition a sense in which time is dependent on motion or movement. This movement is either in the mind (as when vision is thwarted by darkness) or in things which we perceive as moving. This sense of time dependency upon movement is delineated by Michael J. White in his article “Aristotle on ‘Time’ and ‘A Time.’ White declares, “Aristotle sees a very close connection between ‘process’ or motion (primarily locomotion, it seems) and time. Since time is not to be identified with motion, it must be some feature of motion (219a 9-10). It is clear that a conception of time as an ontologically independent ‘container’ of process is quite foreign to Aristotle’s thought; rather, time, or times, are in some way ontologically dependent on things in process.”[11] White’s commentary of Aristotle’s definition of time and motion is quite helpful in placing our finger on what Aristotle is asserting about their connection. However, several questions seem to arise.

If what Aristotle declares is correct, that time is some feature of motion and time is dependent upon some mind, then how can Aristotle account for instances in the sensible world where there is no motion and no minds to perceive? For instance, let us say we have a group of students in a given classroom for one hour participating in a philosophy class. Movement in the room between students, the professor, and the thoughts of the minds of the students, for Aristotle, would constitute that time is elapsing. However, once the class session has ended, the lights have been turned out and the room is now completely motionless (granting that there is not a clock on the wall for there to be motion in the room) and there are no minds in the room, does time elapse in the room? Aristotle would initially say no, there is no time in the room. In this sense (or situation), Aristotle is very much an idealist with his notion of time. It should be pointed out here that Aristotle would probably declare that there is the potential for one to check in with the room in the beginning and walk around (thus providing the needed motion) and at any point in this process, return to the room. So essentially there could still be time in the sense that there is potential countability in the room.

Summing up this section, Aristotle’s view of time, simply put, can be defined as a nonsubsistence (nonbeing) thing which inheres in quantifiable change (‘before’ and ‘after’) and is that which is numbered. For instance, using Aristotle’s exact definition, it can be elaborated upon as such—time is the number (in that it is countable) of movement (in that it inheres in motion) in respect of before and after (in that it is quantifiable change). However, perhaps Aristotle believes that time might be too basic to admit of definition and this is why he begins his discussion of time in an aporetic fashion.

[1] In fact, movement (or motion), change and number are in a sense all closely related in that they serve similar functions. In other words, there is a close and perhaps inseparable connection between these. This will be fleshed out as we examine each.
[2] 219a 22-25, 372.
[3] Ibid., 219b 5-10. This notion will be examined in greater detail a little later.
[4] 219a 1.
[5] J. T. Fraser, The Voices of Time, 2nd ed. (Amherst: The University of Massachusetts Press, 1981), 13.
[6] 226a
[7] Fraser., 13-14.
[8] Philip Turetzky, Time (New York: Routledge, 1998), 20.
[9] 219a 4-5.
[10] 219a 8-9.
[11] Michael J. White, “Aristotle on ‘Time’ and ‘A Time.’” Apeiron XXII, 3 (September 1989), 208-09.

Movement, Change and Number: Aristotle’s View of Time (Part 2)

Aristotle’s Definition of Time

In Physics book 4 section 10 Aristotle begins by questioning the nature of time in terms of being and/or nonbeing. Hippocrates G. Apostle points out that “Aristotle’s usual procedure is to show the existence of a thing before proceeding to its nature or definition, for a nonbeing has neither a nature nor a definition (it may have a formula, like the formula of a circle with two centers, which circle cannot exist). Besides it is easier to observe the existence of a thing than to state its definition, as in the case of a man or a tree.”[1] Apostle’s comments are helpful. In fact Aristotle does attempt to determine, in the beginning of his discussion on time, whether time is being or nonbeing.

Aristotle begins by asking, “does it [time] belong to a class of things that exist or to that of things that do not exist?”[2] From this question Aristotle attempts to determine if time “either does not exist at all or barely, and in some obscure way.”[3] The reason Aristotle asserts that time is suspect, with reference to it having ‘being’ is that time might be divisible. In other words, in aporetic fashion Aristotle plays with the idea that part of time has been and is not and part of time is going to be and is not yet (218a 1-4). However, Aristotle asserts, “if a divisible thing is to exist, it is necessary that, when it exists all or some of its parts must exist. But of time some parts have been, while others are going to be, and no part of it is, though it is divisible.” Aristotle continues this line of thinking by declaring, “For the ‘now’ is not a part: a part is a measure of the whole, which must be made up of parts. Time, on the other hand, is not held to be made up of ‘nows.’”[4] This portion of Aristotle’s text has left centuries of scholars speculating about what Aristotle is attempting not only to communicate, but what he is trying to solve about time as well.

In this difficult passage it seems that Aristotle is at least concluding that time is nonbeing. Thomas Aquinas, in his commentary to Aristotle’s Physics concludes this very thing. Aquinas, commenting on this particular text, writes, “Anything that is composed of things which do not exist cannot itself exist or have any substance. But time is composed of things which do not exist. For one part of time is the past which does not now exist, and the other part is the future which does not yet exist.” Aquinas then concludes, “And from these two things the whole of time, given as infinite and perpetual, is composed. Therefore, it is impossible that time is something.”[5] Moreover, Apostle comments on this same passage by declaring, “If time is considered as composed of parts which do not exist, then time itself does not exist and so it has no nature or substance.”[6] This leads us to the question that if time is not a substance and has no being, then what is it? Following Aristotle’s pursuit of time as being or nonbeing is Aristotle’s question what is time’s nature?

[1] Aristotle, Physics, trans. with commentary Hippocrates G. Apostle (Grinnell, Iowa: The Peripatetic Press, 1980), 259.
[2] Jonathan Barnes, ed., The Complete Works of Aristotle (Princeton, New Jersey: Princeton University Press, 1984), 217a 31, 369. All references from this point will be from this version of the Physics and will be marked with the corresponding numbering in the text unless otherwise noted.
[3] 218a 1-2, 370.
[4] 218a 1-8, 370.
[5] Thomas Aquinas, Commentary on Aristotle’s Physics, translated by Richard Balckwell, et. al. (Notre Dame, Indiana: Dumb Ox Books, 1999), 273.
[6] Apostle, Aristotle’s Physics, 259. (Emphasis in the original).

Movement, Change and Number: Aristotle’s View of Time

I've been wanting to start a philosophical series for some time now. That being the case, I have decided to post a few excerps from some research I did at Marquette University on Aristotle's view of time. This will be the first of several posts to that end. I hope you enjoy the series as much as I did researching the topic.

Introduction

It seems undeniable that time exists, but in what sense does time take on existence? Is time subsistence, logical construct of the mind, or something else? Literally for thousands of years these important questions have not only been asked, but attempts have been made at finding some sort of satisfying answer. Noted philosopher Richard Sorabji comments on these types of questions by declaring, “of course we know that time exists. For one thing, there is something self-defeating about denying its existence; for that very denial requires time in which it takes place. The denial of time is self-defeating in the same way as the denial that one exists or thinks, a denial whose self-defeating character was exploited by Descartes.”[1] It seems that in some sense every sentient purposive being has some rudimentary awareness of time. In other words, fundamentally, distinctions of past and present events and an awareness of these distinctions can be made by purposive agents. And, as Sorabji points out, “any being capable of considering the existence of time is likely to be a purposive agent.”[2]

With this in mind, let’s look back in time at an ancient philosopher who had some very interesting things to say about time. Aristotle, in the Physics (book 4, section 10), delineates certain paradoxes[3] which seem to arise, for Aristotle, when time is considered. The intent of this paper is to examine Aristotle’s view of time. What does Aristotle mean when he declares time to be a number? Is time dependent or independent for Aristotle? Is time a logical construct of the mind or does it actually subsist? Since, as we shall see, Aristotle starts his approach to time from that which is observable, does time then depend upon some mind? Does Aristotle have an idealist conception of time? These questions, and other similar ones will be the focus of this research in an attempt to glean, from Aristotle’s writings, his notion of time.

[1] Richard Sorabji, Time, Creation, and the Continuum: Theories in Antiquity and the Early Middle Ages (Ithica, New York: Cornell University Press, 1983), 7.
[2] Ibid.
[3] For example, time is not movement but is not independent of movement. Also, time is the number of motion pluralized by individual ‘nows’ which are countable, etc.