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PH354 Aristotle

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  1. PH354 Aristotle Week 3. Change (2) Time

  2. Introduction • Aristotle offers an important treatment of time in the Physics. It is a subject of intense scholarly discussion. • Aristotle’s views about both time and the infinite might provoke a characteristic response; that they make the relevant notions mind-dependent, and that that is a problem. • In this lecture, we will look at why this might be thought to be the case, and the suggestive discussion offered by Jonathan Lear (1988) in response. Lear (1988) aims to vindicate Aristotle’s claims about the respects in which time (and infinity) are ‘mind-dependent’.

  3. Lecture Plan • Review some of Aristotle’s basic claims about time, and some of his arguments. • Mind-dependence in the account of time, and some philosophical worries concerning the mind-dependence of time. • Some responses to these worries, from Lear. Are these responses adequate? • Introduce a Modest Approach to reading of Aristotle’s discussion of time, and provide some initial motivation for that view.

  4. The Account of Time in Physics Book VI • Time is not identical with change. • At 218b 9- 20 Aristotle argues; • (a) that change and alteration are in the object that alters, but time is not in the object that alters; it is everywhere. • (b) that change can be faster and slower. But time, he says, cannot be faster or slower. The notions of faster and slower have to be understood in terms of the notion of time (they are “defined in terms of time”).

  5. The Account of Time in Physics Book VI • Though time is not identical with change, change or alteration is necessary for time. • Time is an aspect of change or something of change. (“Time is not without alteration”). • The argument for this is that time cannot be experienced without change being experienced.

  6. The Account of Time in Physics Book VI • And yet time is not apart from alteration (change), either. When we ourselves do not alter in our mind or do not notice that we alter, then it does not seem to us that any time has passed, just as it does not seem so to the fabled sleepers in the sanctuary of the heroes in Sardinia, when they wake up; they join up the later now to the earlier, and make it one, omitting what is in between because of failure to perceive it.

  7. The Account of Time in Physics Book VI • So, just as, if the now were not different but one and the same, there would be no time, in the same way, even when the now is different but is not noticed to be different, what is in between does not seem to be any time. If, then, when we do not mark off any alteration, but the soul seems to remain in one indivisible,

  8. The Account of Time in Physics Book VI • ..it happens as a consequence that we do not think that there was any time, and if when we do perceive and mark off an alteration, then we do say that some time has passed, thus it is manifest that there is no time apart from change and alteration. 218b21- 35

  9. The Account of Time in Physics Book VI “Time is the number of change with respect to the before and after.” • But time, too, we become acquainted with when we mark off change, marking it off by the before and after, and we say that time has passed when we get a perception of the before and after in change. We mark off change by taking them to be different things, and some other thing between them; for whenever we conceive of the limits as other than the middle,..

  10. The Account of Time in Physics Book VI • and the soul says that the nows are two, one before and one and one after, then it is and this it is that we say time is. (What is marked off by the now is thought to be time: let this be taken as true.) So whenever we perceive the now as one, and not either as before and after in the change, or as pertaining to something which is before and after, no time seems to gave passed, because no change seems to have occurred either.

  11. The Account of Time in Physics Book VI • But whenever we do perceive the before and after, then we speak of time…. For that is what time is: number of change in respect of the before and after. So time is not change, but that is that in respect of which change has a number. 219a22- 219b3

  12. The Account of Time in Physics Book VI • Time is the medium in which change occurs. Change has position or positions in time, and the magnitude or duration of change can be numbered and measured in units of time. • Time is number of change in respect of ‘the before and after’. Because change always has a beginning and an end, one can think of the before and after here as the boundaries of change, or the temporal positions which mark the transition between the before and after of change.

  13. The Account of Time in Physics Book VI • But the respect in which Aristotle understands the idea of time as the number of change in respect of the before and after goes beyond this. He refers to the instants of times which mark the boundaries between the before and after of change as ‘nows’. • The introduction of the notion of now introduces a connection to a soul or a subject. A now is an instant of time experienced as present. Where there is awareness of the passage of time, the soul marks off these two nows as different. • Time is not to be identified with any particular now, nor any succession of them. It is a continuity.

  14. The Account of Time in Physics Book VI • But if nothing but soul, or in soul mind, is qualified to count, it is impossible for there to be time unless there is soul, but only that of which time is an attribute, i.e. if change can exist without soul. 223a16- 28 • ‘It is manifest too that, if time were not, the now would not be either, and if the now were not, time would not be.’ (219b33) • Time is that in which change occurs, and has position and magnitude, where change is understood as present at, or, in, the now (that is, to a soul counting the nows, or in a position to count the nows).

  15. Worries about the Mind-Dependence of Time • (1) Aristotle apparently argues that change is necessary for time, because one cannot experience time passing without having experience of change. • This seems to attempt to derive a metaphysical conclusion from a phenomenal premise. • Or: It doesn’t follow from the fact that our experience of F has property P that F has P.

  16. Worries about the Mind-Dependence of Time • (2) Aristotle says: “if there was no time there would be no now, but if there were no now there would be no time”. • Does it follow from the fact that the now, and a succession of nows, is mind-dependent, that time itself is? • For there is a difference between time itself and time being present to conscious experiencers in such a way that there is a ‘now’.

  17. Lear (1988) on the Mind-Dependence of Time • Lear (1988, p.83) says: “If we are to render time intelligible, we must come to understand the constitutive role we play in the objective order of time. We cannot have any understanding of what time is like ‘in itself,’ totally independent of our apprehension of it. For the reality of time is partially constituted by the soul’s measuring activities.” And then he adds, • “Because our experience of time partially constitutes its reality, Aristotle can infer from our experience of time to the very nature of its existence.”

  18. Lear (1988) on the Mind-Dependence of Time • Lear’s reason for thinking that the reality of time is partially constituted by the soul’s measuring activities resides in his reading of the account of time. “In nature there are changes, many of them displaying a certain kind of regularity. Our recognition of this regularity—as manifested by the soul pronouncing the nows—is both a recognition and a realization of time. Time is that which exists in between the nows that the soul pronounces.” (1988: 78).

  19. Lear (1988) on the Mind-Dependence of Time • Either: • He thinks that time is just an experience of change, in which case it might be mind-dependent, but then that leaves it unclear why mind-independent ordered change doesn’t count as time. (After all we think we are aware of time, and change is what we are aware of) It’s a bad theory • Or: • Time is understood as the order or measure of change, in which case showing that the nows or what takes place in between the nows is mind-dependent doesn’t show that the reality of time itself is mind-dependent; it only shows that the reality of our awareness of time is mind-dependent.

  20. Lear (1988) on the Mind-Dependence of Time • Both of the horns of this dilemma appear to presuppose that we have an understanding of what time is like considered independently of beings who are capable of counting the nows. • What about his thought that we have no understanding of what time is like ‘in itself’, totally independent of our apprehension of it?

  21. Lear (1988) on the Mind-Dependence of Time • (a) Should we think that we cannot have an understanding of time considered independently of apprehension? • But that time passes unapprehendedand may have passed completely unapprehendedby anyone is a coherent thing to think! • (b) Does Aristotle think this claim is true? • Not obvious he does. He thinks that we can make sense of the notion of eternity, and that we can state coherent propositions concerning eternal things (like the unmoved eternal mover and eternal motion). Cycles of change seem independent for Aristotle.

  22. Motivating a Modest Approach • Aristotle makes claim about our awareness of time, or our experience of time (i.e. an epistemological or phenomenological idea about time) that are sometime referred to as if they were claims about the mind-independent reality of time. • The object of Aristotle’s discussion is really to establish some truths about what time is in so far as we experience it, or insofar as it figures in our conscious awareness.

  23. Motivating a Modest Approach • In introducing an argument, Aristotle is explicit that he is making a phenomenological claim. Then he allows for a more relaxed mode of expression, in which the qualifying context can be taken to be understood. An example: • “But time, too, we become acquainted with when we mark off change, marking it off by the before and after, and wesay that time has passed when we get a perception of the before and after in change…” • What this means: • Our awareness of time/our experience of time occurs when we ‘mark off change’ by ‘the before and after.’ We say that time has passed = it seems to us that time has passed = our experience of time has having passed….

  24. Motivating a Modest Approach • At the end of the passage • “But whenever we do perceive the before and after, then we speak of time…. For that is what time is: number of change in respect of the before and after. So time is not change, but that is that in respect of which change has a number.” 219a22- 219b3 • Here I suggest that ‘what time is’ just means ‘what time is’ insofar as it is something that we are aware of, or insofar as it is something we have experience of. The claim is elliptical for what has been spelled out more clearly in the thought that starts the passage. It is a claim not about time as a ‘mind-independent reality’, but about our experience of it.

  25. A Modest Approach: Aristotelian Reflections about the Structure of our Awareness of Time • Aristotle’s discussion is intended to bring out what is distinctive about our perceptual or sensory experience of things. • 1. Our awareness of time involves a temporal perspective. • 2. Our temporal perspective has distinctive features that explain ‘time’ in the sense of ‘our awareness of the passage of time’.

  26. A Modest Approach: Aristotelian Reflections about the Structure of our Awareness of Time • The awareness of time or the experience of time involves the now. At any time at which one has experience of change, one’s experience of change represents it as occurring now. • God might be capable of a form of perception of things in time that presents them as independent of the ‘now. • Though we can think this thought, we cannot visually or sensorily imagine what it is like to have a God-like point of view. That point of view isn’t ours. • There is more to our awareness of time than what we are in contact with. It involves facts about our perspective.

  27. A Modest Approach: Aristotelian Reflections about the Structure of our Awareness of Time • The continuous now • Suppose that at some time, t, an experiencer ‘”marks off the now” at that instant of time t’ (i.e. has an experience of the time t, which is present, as being now). • It is not possible for that experiencer to merely mark off the now at that instant of time (something which doesn’t itself have any temporal duration), but he must mark off the nows over a continuous interval of time (a before and after) no matter how small that is. • So the now is a continuity in the sense that one can be aware of an instant of time as now only if one is aware of the now over a continuous interval of time. • WHY?

  28. A Modest Approach: Aristotelian Reflections about the Structure of our Awareness of Time • The experiential state being aware of a time as now must be present over a period of time because it depends on something that is itself a change: experiencing or experience going on. • Experience occupies time in something like the way walking does. Suppose someone is walking at time t. There is nothing for it to be for them merely to be walking at that time. If they are walking at t, they must be walking over a period of time during which t occurs. • (Compare the way that one might be aware of time in having a plan for the day)

  29. A Modest Approach: Aristotelian Reflections about the Structure of our Awareness of Time • Can I be aware of time passing even if there is no change of external to me of which I am aware? (Suppose at t I am aware of things staying the same now) • Even if you are aware of something being at rest now, that awareness depends on the unfolding of the change which is your having experience now. • Being aware of rest depends upon change (your having an experience of a certain kind over a period of time) just as much as does your experience of change.

  30. Lecture Summary • (i) Aristotle says that time is an aspect of change; it is the number of change with respect to the before and after. • (ii) It seems as if Aristotle wants to argue that mind-independent things are a certain way on the basis of the fact that our experience is a certain way. • (iii) We looked at the discussion in Lear (1988). Lear argues that because time is partly constituted by the mind we can argue from experience to facts about time. But it is not clear why this is. We can understand the notion of mind-independent time.

  31. Lecture Summary • (iv) I tried to motivate a Modest Approach that is perhaps similar in spirit to the suggestions made by Lear (1988). Aristotle’s claims about time are not claims about a transcendent mind-independent notion of time. • Aristotle thinks our awareness of time has to be explained in terms of the perspective of the present, and that it is the dependence of the relevant state of awareness on the change that is our experience that accounts for the ‘continuity of time’.