selected papers from the american philosophical association, pacific division, 2004 meeting || plato...

Plato on Necessity and ChaosAuthor(s): Andrew S. MasonSource: Philosophical Studies: An International Journal for Philosophy in the AnalyticTradition, Vol. 127, No. 2, Selected Papers from the American Philosophical Association,Pacific Division, 2004 Meeting (Jan., 2006), pp. 283-298Published by: SpringerStable URL: http://www.jstor.org/stable/4321692 .

Accessed: 25/06/2014 02:47

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

Springer is collaborating with JSTOR to digitize, preserve and extend access to Philosophical Studies: AnInternational Journal for Philosophy in the Analytic Tradition.

http://www.jstor.org

This content downloaded from 91.229.229.210 on Wed, 25 Jun 2014 02:47:18 AMAll use subject to JSTOR Terms and Conditions

http://www.jstor.org/action/showPublisher?publisherCode=springer

http://www.jstor.org/stable/4321692?origin=JSTOR-pdf

http://www.jstor.org/page/info/about/policies/terms.jsp


Philosophical Studies (2006) 127:283-298 ? Springer 2006 DOI 10.1007/sI1098-005-4959-5

ANDREW S. MASON

PLATO ON NECESSITY AND CHAOS

1. INTRODUCTION

In the Timaeus, Plato draws a contrast between intelligence (nous) and necessity: the self-moving soul is characterised by intelligence: material things are governed by necessity. This distinction is central to the Timaeus and helps to give the work its structure. But one half of this contrast, necessity, gives rise to a problem; Plato's conception of it seems, at first sight, very different from our own. We naturally associate necessity with order: Plato, at least in some contexts, associates it with disorder. This has often been found puzzling.

In this paper, I aim first to explain briefly what, in my view, Plato's conception of necessity is, and what part it plays in the work; then to inquire why it seems different from our conception, and to argue that the difference is not as great as might first appear.

The Timaeus describes the creation of the world by God -

not a God who creates ex nihilo but a "craftsman" God who creates order out of chaos. The first part of Timaeus' discourse (27d-47e) deals mostly with things directly produced by God - the heavenly bodies and the rational human soul. The middle section (47e-69a) is concerned with the nature of the material which God takes over, in particular with the four so-called "elements"; the last part (69a-92b) is concerned with what God produces by exploiting the nature of matter, in particular the human body.1

Necessity is introduced at 46d-e as something which governs the behaviour of material things, by contrast with intelligence, which is associated with soul.2



284 ANDREW S. MASON

When necessity is not associated with intelligence it produces chance and disorderly effects:3 this can be read as meaning that material things, when not controlled by a rational mind, behave in a random and disorderly way. But necessity can be controlled and exploited ("persuaded") by intelligence, and so become a factor in the production of orderly and purposive states of affairs; thus it helps to produce the cosmos.4 However, it can also set limits to the power of intelligence. This is most clearly revealed at 75a-c, the description of the creation of the human head; the necessity inherent in the materials prevents the head being both sensitive and well-protected, though that is what the intelligent creators would ideally have wanted.5

Necessity can also be a principle of explanation. For Plato the best explanations are teleological ones, in terms of the purpose things serve, and these are made possible by soul. But there are also explanations in terms of physical causes or conditions, and these appeal to necessity.6 Phenomena produced directly by intelligence may have only a teleological explanation; material phenomena not controlled by intelligence may have only a physical one. But when intelligence produces new phenomena by exploiting the nature of material things, these will have both a teleological and a physical explanation; and in the last part of the Timaeus explanations of both kinds are given for aspects of the human body.7 Thus, the first part of the Timaeus is concerned with intelligence, the second part with necessity, and the third brings the two together.8

2. WHAT IS NECESSITY?

Various different views have been taken about why Plato uses the term "necessity" in connection with material nature. I will defend the view, first set out in detail in the modern debate by Glenn Morrow,9 and also defended by Steven Strange,10 that Plato is referring to what we would call natural or causal necessity; he holds that material things have powers which



PLATO ON NECESSITY AND CHAOS 285

determine, given the circumstances, how they will behave. This reading has many advantages.

First, this reading explains the initial contrast of intelligence and necessity, presented at 46c-e: material things cannot act for a reason because their behaviour is determined by external causes: there is only one way in which they can behave, given the circumstances. The soul, by contrast, moves itself,11 which, I have argued elsewhere,'2 means that it con- trols its own motion: it is not causally determined to act in a particular way, so it is able to respond to reasons.

Secondly, this reading shows how necessity can be a principle of explanation: we can explain an event by showing that it follows necessarily from the powers of materials and their arrangement.

Thirdly, this reading explains how necessity can be exploited by intelligence: if I bring material things into a certain arrangement, a certain result follows necessarily, so I can exploit this to produce a desired outcome.13 But equally, necessity understood in this way can limit the powers of intelligence: there are results which I cannot bring about because some combinations of physical states are not possible.

Finally, this reading is supported by the way Plato describes material things in the section of Timaeus concerned with necessity; he treats them as having a dependable nature. 14 He describes their structure, their motion, their transformation into one another, and their sensible qualities, understood in terms of the way they act on us in perception. They behave in a determinate way in specific circumstances, and this is grounded on their structure.

3. THE PROBLEM OF DISORDER

However, although there are strong reasons for adopting this view, it has not been universally accepted, because of a num- ber of problems. Here I aim to confront just one of those problems and propose a solution.15 Necessity is associated with chance and disorder. When separated from intelligence,



286 ANDREW S. MASON

it produces chance and disorderly effects.16 It is called "the wandering cause". 17 It needs to be 'persuaded' or 'subjected' by intelligence, as if they were at first (or at least potentially) opposed.18 Within the section of the work devoted to necessity, there is a description of the material world before intelligence took control of it,19 according to which it was then in a state of chaos.20 Likewise at the beginning of the work we are told that the sensible world, before God took control of it, was "not at rest but in discordant and disorderly motion"..21

We naturally associate necessity with order - how can Pla- to associate it with disorder? Many writers have been puzzled by this - for instance Gregory Vlastos claims that 'for us, the very idea of necessity implies necessary order'.22 A similar view is taken by A.E. Taylor,23 F.M. Cornford24 and Harold Cherniss.25

In considering this problem it should first be noted that the disorderly aspect of necessity can be exaggerated - as it has been, for instance, by Cornford and Cherniss. They see it as representing the disorderly factor in the world; so for them 'combination of intelligence and necessity' is taken as equiva- lent to "combination of order and disorder".26

But this is not borne out by what Plato says about necessity. The central section of the Timaeus, describing 'things that come about through necessity' is not a description of disorderly phenomena, but simply of material nature, though some aspects of it are disorderly. Likewise when in the last section intelligence is shown exploiting necessity, it is simply presented as exploiting material causes, not disorderly ones in particular.

Intelligence and necessity are first introduced, at 46c-e, as factors in the explanation of the same states and events; they feature in two kinds of explanation of vision, the physical and the teleological. Only later, at 48a, do we discover that they are, at least potentially, opposed. As the example of vision shows, both can feature in the explanation of good and purposive processes.




At 48a Timaeus states "intelligence prevailed over necessity by persuading it to direct most of the things that come to be towards the best, so that this universe was produced by necessity subordinated to intelligent persuasion." I would suggest that his language should be taken seriously; necessity directs things towards the best, and plays a part in the production of the cosmos.27

According to 46e5-6, necessary causes when isolated from intelligence produce random and disorderly results, but this does not mean that they always do so.28

Nevertheless, though necessity cannot be simply identified with disorder, it clearly has a disorderly aspect, as the passages cited above show; and it remains a problem how natural necessity is compatible with disorder.

One way out is to deny that "necessity" refers to natural necessity at all. Various other ways of interpreting it have been proposed. One, which is indeed supported by some of the statements that Plato makes about necessity, is the "factual" interpretation, proposed by I.M. Crombie.29 On this view material nature is necessary in the sense of being inevitable; something which we are confronted with and can do nothing about. The material aspect of the world is an element of brute fact; something confronting intelligence, which it can make use of, but cannot eliminate, and which sets limits to what intelligence can do.

Certainly Plato does sometimes think of material nature in this way - whether or not he uses the term "necessity" to refer to this aspect of it. Moreover, it is certainly possible to read some of the passages where necessity is mentioned in this way; e.g. 68el-2 "All these things, being constituted in this way by necessity, were taken over by the maker of what is finest and best in things that come to be", and 75a7-b2 'For the nature which arises by necessity and which grows with us in no way allows thickness of bone and abundance of flesh together with sharpness of perception'; in these passages, and perhaps espe- cially the first, "by necessity" could well mean "inevitably", "in a way which intelligence could do nothing about".



288 ANDREW S. MASON

However, on this reading it is harder to explain 46c-e, where necessity is first introduced;30 this certainly seems to speak of a relationship between events, in which one thing follows necessarily on another, and this supports a causal reading. Moreover, the factual reading makes it harder to see how necessity can provide an explanation of events; to say that something is true as a matter of brute fact seems rather to be a refusal to explain it. On the other hand, natural or casual necessity, in which one event or state follows necessarily on another, will allow the second event or state to be explained in terms of the first.

In the end, we may want to conclude that the two readings need not be seen as mutually exclusive; material nature might be both necessary in the sense of inevitable, and characterised by necessity in the sense that one thing follows necessarily on another. Indeed, it is possible that Plato is using "necessity" in both senses; when he speaks of the existence of material things coming about "by necessity" (as he does at 68e and perhaps at 75a) he may mean simply that it is inevitable, but when he speaks of its behaviour as necessary (as at 46e) he means that it follows necessarily on prior conditions.

Another possible way of understanding "necessity" in the Timaeus is the "hypothetical" interpretation, suggested by Cornford31 among others; on this reading, material nature is characterised by necessity in the sense that it is necessary for bringing about the aims of intelligence. Thus, the distinction drawn in the Timaeus between things produced by intelligence and things which come about through necessity would be that between things which are desirable in themselves and those which have a merely instrumental value.

This interpretation is suggested by the Phaedo,32 where Socrates describes the material conditions, normally thought of as causes, as "necessary conditions"33, by contrast with the real cause, which is intelligence; this distinction is similar to that made at Timaeus 46c-e. Moreover, "necessary" is used in this sense in at least one place in the Timaeus; at 75el-2, on the functions of the mouth, we are told that it is 'a place




where necessary things may enter and the best things may pass out'; food is necessary (to survival), by contrast with speech, which is valuable in its own right.

Once again, this does seem to point to a genuine feature of Plato's necessity; material things are indeed necessary, in his view, for achieving the aims of intelligence. But once again this interpretation does not answer the question how necessity can provide a form of explanation. In the Phaedo Socrates is arguing, precisely, that material factors are not explanatory; the structure of Socrates' bones and sinews is necessary to his sitting in prison, but would be equally necessary to his run- ning away.34 In the Timaeus, by contrast, these factors are to some extent rehabilitated; they can provide an explanation, though not a complete one. Hypothetical necessity could, of course, feature in explanations, but it would work the other way around; the factors which are hypothetically necessary are explained by reference to the end which they serve. How- ever, in the Timaeus the properties of matter are themselves treated as a source of explanation; they can only play this role in virtue of their causal powers.

4. NECESSITY AND CHAOS

If, then, we accept the causal interpretation, how can we overcome the problem of disorder?

First we may note that there are various different aspects of order, and they can be separated. Necessity may imply some kinds of order, but not others. Necessity does seem to imply order in one sense: regularity in the sense, simply, of having a rule. If something is governed by natural necessity, so that, given certain circumstances, it must behave in a certain way, it follows that if those circumstances are repeated it will behave in the same way. So its behaviour will be regular in the sense that there is a rule to it. But it does not have to be regular in the sense of being periodic, of returning to its starting-point and repeating the same process (a sense in which "regular" is often used); hence, it does not have to



290 ANDREW S. MASON

move in a visibly orderly pattern. Nor does it have to be in practice predictable.

When Plato says that necessity, when separated from reasoning, produces disorderly results, must he mean that they are not in any way regular? I suggest that it is more likely that he means they lack periodicity and predictability. The fundamental contrast, for him, between intelligence and necessity concerns purpose and the good; material things, which are governed by necessity, are 'not capable of any reason or intelligence directed towards anything';35 thus, when left to themselves, they cannot act for a purpose or (except perhaps in a purely accidental way) produce any good.

When Plato refers to events in the absence of intelligence as disorderly, it is reasonable to think that the order they lack is some aspect of the good. It is not clear why regularity simply in the sense of having a rule should be seen as a good: by contrast both periodicity and predictability can be seen as such. Periodicity is a form of stability, which Plato certainly sees as a good; the periodic movements of the heavens are for him a paradigm of order, which bring the universe as close as possible to the complete stability of eternity.36 Predictability helps rational beings to understand the world and to organise their lives in it. A world without intelligence would lack order in these senses; but it is quite possible to have a system which does so, and yet is governed by necessity.

And this, it seems, is what we do have. We believe that the physical world is, to a large extent, deterministic - it is governed by natural necessity - and yet it contains many disorderly phenomena. Things like the weather, or the incidence of earthquakes, and so on, do not happen at regular intervals, and normally we cannot predict them. In fact, the only purely natural phenomena that we can predict, in a detailed way, are the movements of the heavenly bodies. Certainly, we can with some assurance make general statements about what happens in the natural world - we can set out laws of nature, as for instance that when a heavy body is released it will fall, or that wood will burn when brought into contact with fire; we




can also make statistical generalisations, as when we say what weather is typical of summer and what of winter. But Plato's concept of necessity allows for this; the section of the Timaeus devoted to necessity does contain general principles governing the motion of the elements, their transformation, and so on. If it is disorderly, this must be in the sense that particular events lack pattern and are unpredictable.

Plato also refers to necessity, in the absence of reasoning, producing chance events,37 and it is often supposed that this reference to chance must be incompatible with natural necessity. But both "chance" in English and tuche in Greek can have various senses. "Chance" can be used to refer to what is wholly undetermined. But it can also be used, either of what does not happen for a purpose, or of what is unpredictable. In both these senses it is compatible with determinism. This is shown by the existence of games of "chance". We do not suppose that the fall of dice, for instance, is genuinely undetermined. If we knew the exact speed and direction with which a die was thrown, together with any other forces acting on it, we would be able to predict how it would fall. But since in fact we do not normally know these things, we cannot predict it, and so we can call it a chance outcome.

Recent scientific developments have brought this connection between necessity and disorder to public awareness in a particularly dramatic way. According to chaos theory, which has developed since the 1960s, there are some systems -

weather systems are an example - which are governed by a deterministic equation, but not periodic - they do not return to their starting point - and not predictable.38 This is because they have sensitive dependence on initial conditions -

i.e. if the initial conditions are changed ever so slightly, the way the system develops may be completely different. With other systems, if the initial conditions are known approximately, we can approximately predict what will follow. With chaotic systems this is not so; their behaviour can be predicted only if the initial conditions are known with infinite precision - which is not possible for us, though perhaps it is



292 ANDREW S. MASON

for God. As scientists focus more on these systems, this frees us from the assumption that what is governed by necessity must be orderly and predictable.39

However, we do not need chaos theory to show us this: many systems which are in principle predictable by a finite being cannot in practice be predicted because of the complexity of the phenomena involved; thus, they can be seen as examples of disorder, and in some cases of chance. The fall of dice and similar phenomena illustrate this. Another recent scientific development has been the paying of a new attention to the phenomenon of complexity, and how different factors can combine to produce results that could not arise from any one of them in isolation. Of course it has always been known that this is possible; what is new is the tendency to focus on it, rather than making idealisations which lead to its being overlooked, and concentrating on simple systems.

Another way in which necessity may be connected with disorder is provided by the Second Law of Thermodynamics, according to which the entropy of a closed physical system tends to increase. Entropy is often identified with disorder, though it does not seem to be the same as disorder in the senses we have been considering up to now; systems with high entropy are not necessarily unpredictable (though the process of transition from low to high entropy in a system is typically chaotic in the technical sense.40) Rather, entropy is uniformity of energy distribution in a system; a system with high entropy will lack order in the sense of structure; it will lack differentiation and so the ability to carry information. It follows from the Second Law that natural processes will tend not to produce highly structured systems; it is reasonable to think that Plato would see unstructured systems as examples of disorder, so this once again coheres with his view that necessity, when separated from intelligence, produces disorderly results.

Thus, it seems possible to connect necessity with chance and disorder. Why have many people in the modern period found this connection unnatural?




One reason may be that we are familiar, as Plato was not, with large-scale machines, and we often take to be paradigms of necessity; we refer to "mechanical necessity", and so on. Machines do indeed move in a regular, predictable way. But in fact machines are a special case. They are certainly paradigms of necessity in that they have no control over what they do; their behaviour is wholly governed by physical laws. But they are visibly regular and predictable because they have been organised by a rational agent for a purpose; in this re- spect they are not typical of physical systems. In Plato's terms they are examples of necessity persuaded by intelligence, rather than necessity in isolation from intelligence. We should take care in using the concept of the mechanical; something may be mechanical in one sense, in that it is governed by purely physical laws and has no control over what it does, but not like a machine in other ways, in that it does not behave in a visibly regular way or serve a purpose.

However, perhaps the main reason why Plato's link between necessity and disorder seems alien to us derives from the discovery, by Newton, that the regular movements of the heavenly bodies can be explained by natural laws - the same laws which govern falling apples, and the like. Plato had supposed that, because the heavenly movements were so orderly and regular, they could not be produced by necessity, but must be under the direct control of intelligence. Newton shows that this is wrong. But again, the heavenly bodies are a special case; they are not typical of natural phenomena. New- ton shows that necessity can produce order; but it does not follow that it is typical of necessity to produce order. When we learn that earthly phenomena are governed by the same laws as the heavenly movements, it becomes tempting to see the heavens as paradigmatic of things governed by natural law, and to hope that we will be able to see the whole universe as behaving in the same orderly, predictable way. But this does not follow directly from Newton's laws; it is simply a world view to which Newton's discoveries tend to give rise. I suggest that we should not adopt this view; natural



294 ANDREW S. MASON

necessity is not always associated with order and predictability. The fact that Plato was wrong about the heavens should not blind us to the fact that he was right about many other things; many phenomena governed by necessity are indeed disorderly.

To sum up: Plato associates necessity with disorder, and at first sight this seems extremely alien to us. But I have argued that we can distinguish aspects of order. In one aspect, regularity in the sense of having a rule, it is indeed essentially connected with necessity. But there are two other aspects - regularity in the sense of periodicity, and predictability -

which are separable from necessity; what is governed by necessity can lack these kinds of order. In the light of this, Plato may turn out not to be as alien as he first appears.4'

NOTES

1 This is in fact an oversimplification of the structure of the Timaeus, since the section ostensibly devoted to Necessity in fact includes some things produced by God (e.g. at 53b5 if. God is presented as structuring the elements): but Plato encourages us to structure our thoughts in this way, since at the beginning of the middle section he claims that he is now introducing a new kind of cause or explanation (48a5-b3), while at the end of the section he claims that he has now finished describing the kinds of cause separately, and they can now be combined (69a6-b2).

2 "Of existing things that to which alone intelligence may belong should be called soul - but that is invisible, while fire and water and earth and air have all been generated as visible bodies - and the lover of intelligence and understanding must search first for the explanations which belong to the intelligent nature, and second for those which arise from things which, when moved by others, themselves of necessity move yet others.' (Tim. 46d5-e2) (Translations are my own except when other- wise noted. This association between intelligence and soul need not imply - as F.M. Cornford, Harold Cherniss, and others have supposed - that the creative intelligence is merely symbolic of intelligence in the World Soul, or of rational soul generally; it is possible to conceive of the creator as a soul, and yet as existing prior to and independently of the world).

3 "Those [causes] which, when isolated from reasoning, bring about on each occasion whatever disorderly thing chances to happen" (Tim. 46e5-6).

4 "Intelligence governed necessity by persuading it to guide most of the things that come to be towards the best, so that this universe was




constituted in the beginning through necessity subjected by intelligent persuasion" (Tim. 48a2-5).

5 "For the nature which arises by necessity and which grows with us in no way allows thickness of bone and abundance of flesh together with sharpness of perception. For the constitution of the head would certainly have had both, if they had been willing to occur together, and the human race, having a strong fleshy and sinewy head, would have obtained a life double, or many times, what it lives now, and healthier and more free from pain. But now, when our makers considered whether they should produce a race that was worse, but longer-lived, or better, but shorter- lived, they decided that a shorter but better life was altogether more choiceworthy than a longer but worse one' (Tim. 75a7-c3). (The "makers" are the heavenly gods, who carry out the construction of the human body on behalf of the supreme God or Craftsman).

6 "The lover of intelligence and understanding must search first for the explanations which belong to the intelligent nature, and second for those which arise from things which, when moved by others, themselves of necessity move yet others" (Tim. 46d7-e2). "we must distinguish two kinds of explanation, the one necessary, the other divine, and we must search for the divine in everything for the sake of obtaining a happy life, so far as our nature allows it, but [we must search for] the necessary for the sake of the divine" (Tim. 68e6-69a2).

7 See, for instance, the double explanation of hair at 76b-d, and of nails at 76d-e. This method of double explanation is also anticipated at 45b-47c, where the distinction of intelligence and necessity is first introduced, in the context of the explanation of vision; it is explained both in terms of its purpose and of the necessary processes which bring it about.

8 "What we have already gone through in our discourse, then, except for a few things, has revealed the things brought about by intelligence; but we should also put alongside it in our discourse the things that come about of necessity. For the generation of this cosmos is mixed and arose from the combination of intelligence and necessity... If, then, anyone is to say how in reality it came to be in this way, the form of the wandering cause must be mixed in, how its nature is to cause motion; therefore we must go back again, and, taking up again another appropriate starting- point for these same matters, start again at the beginning with regard to these things now, as we did about the others before." (Tim. 47e2-48b3). "All these things, being constituted in this way by necessity, were taken over by the maker of what is finest and best in things that come to be, when he produced the god which is self-sufficient and most perfect [the cosmos], using the causes connected with these things as servants, but himself crafting the good in all things that come to be... Since, then, the materials now lie sorted for us, as for builders, the kinds of explanation, from which the rest of our discourse must be woven, let us go back again,



296 ANDREW S. MASON

briefly, to the beginning, and advance swiftly to the point from which we came here, and let us try to add a final starting-point to our account, fit- ting in with what went before" (Tim. 68el-69b2).

9 Morrow (1965). 10 Strange (1985). 11 While the self-motion of soul is not explicitly referred to in this pas-

sage, the contrast between the soul and 'things that are moved by others' suggests that it is to be borne in mind; and necessity is linked with the claim that material things are moved by others at 46el-2.

12 Mason (1998). 13 See Morrow (1965) 428. 14 This again is argued by Morrow (1965) 428. 15 The other major problem facing this interpretation, which I cannot

address here, is of course that of persuasion; if something is governed by natural necessity, and its behaviour is therefore determined, in what sense can it be persuaded?

16 46e5-6. 7 48a6-7. 8 48a2.

19 52d2-53b5. 20 For instance at 52a7-8 'all these things [the primary bodies] then

lacked proportion and measure'. 21 30a4-5. 22 Vlastos (1941) 296. 23 Taylor (1928) 300. 24 Cornford (1937) 171-172. 25 Cherniss (1964) 29(40). 26 Cornford (1937) 176-177; Cherniss (1944) 422. 27 Translations such as 'by the victory of reasonable persuasion over

necessity' - so Cornford (1937) 160 - are therefore deceptive. 28 In the light of the evidence mentioned above that necessary causes

play a part in the production of good and orderly states of affairs, it seems that monotheisai phroneseos should be translated as "when isolated from intelligence", rather than "being devoid of intelligence" or the like, which would suggest a permanent condition. (Cornford (1937) 157, writes "being destitute of reason"; by contrast, Zeyl, in Cooper (1997) 1249, gives "when deserted by intelligence").

29 Crombie (1963) 216 if. and 224-227. The interpretation proposed by A.E. Taylor, in Taylor (1928) 299 ff., is in some ways similar; however, on his view necessity is only apparently a brute fact, and if we had a full understanding of the world would turn out to be itself a product of intelligence.

30 See Note 2 above. 31 Cornford (1937) 173-174.




32 Phd. 99a-c. 33 Literally "that without which the cause would not be a cause" (Phd.

99b2-3). 34 See Phd. 98e5-99a4. 35 Tim. 46d4. 36 Tim. 37c-39e. 37 Tim. 46e5. 38 On this see Hunt (1977), Stewart (1989) and Smith (1998). 39 "Predictable" here does not mean the same as "determined". It is

true that there is still a sense in which such systems are predictable, since if their initial state is known with perfect precision their subsequent behaviour can be predicted; this, however, is a very "in principle" sense of "predictable"; it does not allow actual prediction by any finite being. This should be contrasted with some non-chaotic systems, which may be unpredictable for practical purposes because of the complexity of the phenomena involved, but really could be predicted if sufficiently accurate measurements were made.

40 I am grateful to Alexander Bird for this point. 41 I am grateful for discussion of this paper to Alexander Bird, Sarah

Broadie, Fritz-Gregor Herrmann, Thomas Johansen, Henry Mendell, Dory Scaltsas and Steven Strange.

REFERENCES

Cherniss, H.F. (1944): Aristotle's Criticism of Plato and the Academy I, Baltimore: Johns Hopkins Press.

Cherniss, H.F. (1964): 'The Sources of Evil According to Plato', Proceedings of the American Philosophical Society 98, 23-30 (reprinted with original pagination in Cherniss, Selected Papers, Leiden, Brill, 1977).

Cooper J. (ed.) (1997): Plato, Complete Works, Indianapolis: Hackett. Cornford, F.M. (1937): Plato's Cosmology, London: Routledge and Kegan

Paul. Crombie, I.M. (1963): An Examination of Plato's Doctrines, Vol. II,

London: Routledge and Kegan Paul. Hunt, G.M.K. (1977): 'Determinism, Predictability and Chaos', Analysis 47,

129-133. Mason, A.S. (1998): 'Plato on the Self-Moving Soul', Philosophical Inquiry

20, 18-28. Morrow, G.R. (1965): 'Necessity and Persuasion in Plato's Timaeus', in

R.E. Allen (ed.), Studies in Plato's Metaphysics, London: Routledge and Kegan Paul.



298 ANDREW S. MASON

Smith, P. (1998): Explaining Chaos, Cambridge: Cambridge University Press.

Strange, S.K. (1985): 'The Double Explanation in the Timaeus', Ancient Philosophy 5, 25-39.

Stewart, I. (1989): Does God Play Dice?, Oxford: Basil Blackwell. Taylor, A.E. (1928): A Commentary on Plato's Timaeus, Oxford: Clarendon

Press. Vlastos, G. (1941): 'Slavery in Plato's Thought', Philosophical Review 50,

289-304.

Department of Philosophy University of Edinburgh David Hume Tower George Square, EH8 9JX Edinburgh UK E-mail. [email protected]



selected papers from the american philosophical association, pacific division, 2004 meeting || plato...

Documents