Plato on Being and Change

How can a person in himself obtain knowledge about the being of things in the world? The question of knowledge, of finding out the essence, the "core" of reality, of what are the existing things in themselves, and how are they to be defined, is central in Plato's Dialogues, as it is for the philosophers of ancient Greece in general, because a happy life is only possible by knowledge of the good and of the evil. To live knowingly is man's supreme possibility and with knowledge man is transformed, he transcends his own boundaries. To live knowingly for Plato is to live by the means of intellectual perception, for knowledge is not so much in the experience, as it is in the reasoning about that experience. Only a principle, a conception can be the starting point for knowledge, because only a conception can be as valid as to apply to the whole wide range of phenomena, and at the same time it is only the conception, which can be so concrete, as to be referred to in a definition, in the outlining of things' boundaries, in giving the "logos" of things. This becomes obvious as early as in the "Meno', where the stress is laid not on what a virtue is (as an example of it), but on what virtue is (as a concept, a definition). Besides the world of the ever-changing perceptions there is a world of the unchanging meanings (definables), which can be observed by the mind. A figure (circle, or a triangle) can be defined, but the concrete object, which has this shape may change, along with the other properties that it has, besides its shape. Our mind makes the different types of perception an object of general reasoning, and, again, there exists reasoning which does not have perceptional grounds. The thought that is concerned with itself, that examines itself, is the main issue of Plato's speculations, of the Greek philosophizing in general and afterwards in the tradition of the whole Western Europe's thought-system. Plato sought to find out the main principles of being - not its concrete manifestations, functions or attributes, because this was the only way to make a life harmonious - to live according the main principle of being, according "all those characteristics which we designate in our discussions by the term 'absolute' " ("Phaedo", 75d)1 . It is well known, that Plato's theory of the Forms is born out of the theory of flux, and the relation between these two doctrines of major importance for our understanding of Plato, giving meaning to the attempt of our inquiry in the pages that follow.

The distinction between being and becoming, between the realm of things which are never stable in any way and the things which never change in any way and their relation to the theory of knowledge can be found as early as in "Cratylus", then in Plato's middle dialogues "Phaedo", "Symposium", "Republic", and with a sharpest clarity in "Theaetetus" and in "Timaeus". How is the theory of flux represented in Plato's dialogues, is there always a sharp distinction between the worlds of being and becoming, what is the development of Plato's view on the ever-changing realm of being and does Plato follow an extreme variant of Heraclitus' theory or a more moderate one, will be the points of our interest and investigation in the following pages.2

Perceptible knowledge is unstable and indefinable, it is something that gives only subjective, shifting criteria of truth. It is an expression of the instability in the being of things themselves. For Plato the doctrine of Protagoras about the man as a measure of all things (i.e. an individual cannot be mistaken about what seems to him here-and-now, because the appearance of things is relative and unique to each person) is closely related to the doctrine of Heraclitus of the unquestionable change, flux, movement of being in general. Plato did not reject that the reality, which is given to us in our perceptions, that this reality is in a ceaseless, perpetual change, but he was questioning whether this indefinable reality is all that exists, is knowledge nothing but perception, or whether it is only one side of being. Plato thought (in contrast to Heraclitus' theory) that if the reality of the everchanging was the only possible existing reality, if it covered everything that exists, then we couldn't have been given even this relative equilibrium which we come across in our perceptual experiences. If everything was flux our perceptions wouldn't have existed, since all perceptions would be expiring at the moment of their birth. If I begin perceiving and stop perceiving at the same time, could it be said that I perceive at all? How, then, did the thesis of Protagoras hold true for Plato? How should we interpret Aristotle's testimony in "Metaphysics" I, (at 987a32,f), that Plato ever since his youth became familiar with Cratylus and with the doctrines of Heraclitus, that all sensible things are in flux and there can be no knowledge of them, and held on to these views also after his youth? Aristotle interprets the flux-doctrine in the extreme variation of it, that everywhere and in every respect the world of nature is changing (Metaphysics IV,5, 1010a7,f), but can we find support for this view in Plato's Dialogues themselves?3

In one of Plato's early dialogues, ("Cratylus"), the existence of flux reality is introduced from a very interesting perspective, being connected with the problematic of the dialogue in general. If words represent the nature of things, as Cratylus holds in the dialogue, meaning that words represent things by resembling them and reveal the nature of things in this way, then reality can be envisaged by the studying of the words and not the things they stand for. Socrates does not agree to this by saying that different languages have different representations, some being constant by nature, and others fluid. What is behind the words representing reality, are they fluid or constant, that is the main question. Because if everything that there is, including the Forms, is in flux, no knowledge would be possible, and even no perception at all: "And can we rightly speak of a beauty which is always passing away, and is first this and then that? Must not the same thing be born and retire and vanish while the word is in our mouths?"(439e). Thus, beauty does not change, and if it does change, it couldn't be known; the change in sensible things becomes a proof for the existence of Forms: "For knowledge too cannot continue to be knowledge unless continuing always to abide and exist. But if the very nature of knowledge changes, at the time when the change occurs there will be no knowledge, and if the transition is always going on, there will always be no knowledge, and, according to this view, there will be no one to know and nothing to be known. But if that which knows and that which is known exist ever, and the beautiful and the good and every other thing also exist, then I do not think that they can resemble a process of flux, as we were just now supposing."(440b-c). It seems that it follows from here not only that unless knowledge has a fixed sense it cannot be defined, because of the ever shifting meaning of knowledge (where every x is a case of non-x at the same time), and not only the knowledge of what is in flux is impossible, but a flux theory in its extreme manifestation could not allow for there always not to be one to know and nothing to be known, since everything is always in transition. If everything was in flux the situation of "unknowing", of the lack of knowledge and stability, would also have to be subject to change - into something different, lasting . Forms make the world intelligible, give order to the universe, and a flux of Forms would make knowledge impossible, there would be nothing that holds "true", there would be a chaos of shifting, emerging and falling apart things, and not the existing harmony - the cosmos. For Plato there is a structure of reality to be grasped, that is not a haphazard conglomerate of things, because the sensible universe is formed according to a certain structure, in relation to an ideal - an ideal by which all actual phenomena are to be judged.

The distinction between being and becoming is also present in the "Symposium", again in a very specific context, as Plato brings into discussion the problem of human identity. The world of the perceptible is separated from the world of the everlasting: even if the individual is being the same, continuing to exist in the same form, holds Plato, and on this we base our understanding of a person's sameness (identity) in time "yet, for all we call him the same, every bit of him is different, and every day he is becoming a new man, while the old man is ceasing to exist, as you can see from his hair, his flesh, his bones, his blood, and all the rest of his body. And not only his body, for the same thing happens to his soul. And neither his manners, nor his disposition, nor his thoughts, nor his desires, nor his pleasures, nor his sufferings, nor his fears are the same throughout life, for some of them grow, while others disappear" (207d-e). The same applies to the human knowledge, which is never the same, and some of the things we know increase, and some of the things we know are lost. Every mortal creature perpetuates itself, and quite unlike the divine, which is the same throughout the eternity, "it can only leave behind new life to fill the vacancy that is left in its species by obsolescence" (208a). The body is temporal and this is the only way it partakes of the eternal. And the vision of the beautiful cannot take form of a face, or of hands, or of anything that is of the flesh, "but subsisting of itself and by itself in an eternal oneness, while every lovely thing partakes of it in such sort that, however much the parts may wax and wane, it will be neither more or less, but still the same inviolable whole"(211b). And a little bit before that: "It is an everlasting loveliness which neither comes nor goes, which neither flowers nor fades, for such beauty is the same on every hand, the same then as now, here as there, this way as that way, the same to every worshiper as it is to every other"(211a). That, which pertains to the body, that, which is sensible must change in time, while the Forms do not.The sharp contrast between the two worlds is clearly present in the "Phaedo": "Does that absolute reality which we define in our discussions remain always constant and invariable, or not? Does absolute equality and beauty or any other independent entity which really exists ever admit change of any kind? Or does each one of these uniform and independent entities remain always constant and invariable, never admitting any alteration in any respect or in any sense?... Well what about the concrete instances of beauty - such as men, horses, clothes, and so on - or of equality, or any other members of a class corresponding to an absolute entity? Are they constant, or are they, on the contrary, scarcely ever in the same relation in any sense either to themselves or to one another?... So you think we should assume two classes of things, one visible and the other invisible?. .The invisible being invariable and the visible never being the same?" (78d-79b).

These two "classes" of entities are not only contrasted, but they are opposed as the "class" of the never changing in any way, and the "class" of the ever changing in every way, drawing a sharp line between the existence of the two types of realities. Knowledge of perceptible things cannot be achieved because they are in a perpetual change, the soul uses the instrumentality of the body, says Plato, for any inquiry, and "because using the body implies using the senses - it is drawn away by the body into the realm of the variable, and loses its way and becomes confused and dizzy, as though it were fuddled..." (79c). Thus, the body is a hindrance to knowledge, because the senses are not clear and accurate (65a-b), and since this is the way we conceive of the becoming, via our sense perceptions, everything that applies to this realm is similarly unclear and inaccurate, no knowledge of it can be adequate. Because the world perceived by the senses is subject to variations and is entirely deceptive, wisdom (philosophy) "urges the soul to refrain from using them unless it is necessary to do so" (83a-b).

In the Republic, Book V, Plato again distinguishes between "that which purely and absolutely is" and that, which "both is and is not", meaning the two worlds, of being and of becoming (478d5-7). And again, no predicates can be applied to those things that belong to the class of the becoming. This class always admits predicates that are opposite to one another (great and small, light and heavy), making things "always hold of, partake of, both"(479b). Those multiples are "too equivocate, and it is impossible to conceive firmly any one of them to be or not to be or both or neither", and "if anything of that sort should be discovered, it must be denominated opinable, not knowable, the wanderer between being caught by the faculty that is betwixt and between" (479c-d). While the idea of the thing in itself (the idea of beauty, as the example goes) in itself always remains the same and unchanged(479a). Perceptible things always change, because they simultaneously manifest opposite properties, appearing different to different perceivers, or different to the same perceiver at different times, because the perceiver has changed, or because the object perceived has changed, or both, while the Forms are unchanging. And exactly for the reason the perception of everchanging things manifests opposite properties, relative properties, the intellect is invited to reflection: the sensation yields nothing that can be trusted (523b-c). The objects approached by perception cannot be known, they are only opined of, which is something not to be relied on, it is also something that endures changes: "When it [the soul] is firmly fixed on the domain where truth and reality shine resplendent it apprehends and knows them and appears to possess reason, but when it inclines to that region which is mingled with darkness, the world of becoming and passing away, it opines only and its edge is blunted, and it shifts its opinion hither and thither, and again seems as if it lacked reason"(508d).The world of flux, of becoming and passing away, gives nothing but uncertainty. The demonstration of opposite properties in the realm of appearances is due to the perpetual flux and this never ceasing flux accounts for the approach to this realm, by opining. Opining applies only to indeterminate objects, of which no representation is possible, which means that they are in the conditions of extreme flux. And even if they are not represented of in the "Republic" as mere sensations, as it is done in the "Phaedo", but as things that can be opined of, even this does not change the interpretation of the flux doctrine as an extreme variant so far.

The distinction between being and becoming takes a sharp form in the "Theaetetus" as well4 . Heraclitus' flux doctrine is linked to Protagoras' thesis that man is the measure of all things. The connection between the two theories can be formulated that nothing is ever being one thing by itself, and every case of x is also a case of non-x: "I will tell you, and indeed the doctrine is a remarkable one. It declares that nothing is one thing just by itself, nor can you rightly call it by some definite name, nor even say it is of any definite sort... And the things we are pleased to say "are", are really in process of becoming, as a result of movement and change and blending with one another. We are wrong to speak of them as "being", for none of them ever is; they are always becoming" ("Theaetetus", 152d-e).The flux doctrine is an explanation that nothing can be qualified in any way, and perception, which is equal to appearance, is relative both in the sense that the same thing, without a change in itself, can look different to different observers, and in the sense that it can even look different to the same observer, if he concludes, that he has changed rather than the object which he perceives (the change of the object in time is the main issue in the "Timaeus" and in the "Protagoras" and will be considered further on).

The sharp opposition between being and becoming undergoes in the "Theaetetus" an interesting development. The doctrine that everything is changing is suddenly replaced by Plato with the startling statement that everything is a change, that there aren't anymore things that change, but only changes:

". . the universe really is motion and nothing else", says Plato ("Theaetetus", 156a). Not only things perceived, but the subjects that perceive them are denied to have stability and interpreted as a succession of different and changing constituents. In order to be able to interpret this strange shift, we must inquire into the way Plato views what change is and into the way he conceives of what a perceptual judgement is.

In the "Theaetetus" Plato distinguishes two kinds of change -active and passive - and in their interacttion generates the "twin offspring" of a perceiving and a perceived object, which are inseparable: " And there are two kinds of motion. Of each kind there are any number of instances, but they differ in that the one kind has the power of acting, the other of being acted upon.

From the intercourse and friction of these with one another arise offspring, endless in number, but in pairs of twins. One of each pair is something perceived, the other a perception, whose birth always coincides with that of the thing perceived" (156a). At the same time changes are described as "slow" and "quick": "The slow has its motion without change of place and with respect to what comes within range of it, and that is how it generates offspring, but the offspring generated are quicker, inasmuch as they move from place to place and their motion consists in change of place"(156c-d). Thus, if we take the example of sight, both eyes and the objects they see are "movements", and they have no stability, belonging to the realm of becoming. They are all slow movements (they do not change place), and when they interact together, they give rise to a percepted (whiteness as the example goes), and to the perception that corresponds to it (vision), both, whiteness and vision, being produced by the particular coming together. The meeting of sense organs and objects gives rise to perception, perception arises "in between".5 There is a duality between perceived and perceiving, seeing and being seen, each of them being dependent in its existence on the other, since neither of them takes place unless the rays mingle together. A color cannot be located in the eye or outside it, in the object that is seen, or assigned any place at all. To assign a place to it would be identical to saying that things are at rest, while the doctrine holds them coming to be. Thus a perception comes into being as a collision between the sense organ and the object perceived, it is something that comes to being between them, as a motion from the organ that perceives ( a motion from the eye) rather than the organ itself, and a motion from the object seen.6 It is interesting to note that there is a difficulty observed here by philosophers (Crombie, Bostock): when seeing travels from the eye and from the object and the eye becomes full of seeing and so sees, or color travels from the object and the object becomes "filled all around" with the color, becoming this color - how is it that a thing becomes full of what is traveling away from it? And then, how does this theory explain the puzzle with the 6 dice ( 6 dice being more than 4 and less than 12), that Plato puts forward in the "Theaetetus"? The link may be in considering both, the cases of "more" and "less" and the cases of perception as a relation , because it takes always two things to make the case, all a matter of being "in between" two things, and relations are not identical to properties. The so-called sensible qualities (colors) are not regarded by Plato as qualities, it seems, but as relations. And then, not even the characteristics of "agent" and "patient" can belong to the things themselves, for what is at one moment an agent turns into a patient at the next (157a).

A perception gives us the relation between the object perceived and ourselves. Then all my perceptual judgements hold true because they merely indicate the way objects are related to me (even if for an instant), the way things appear to me (even if at certain point). No contradiction could be possible, because the judgement merely signifies the way the object appears to me, which is quite compatible with the way it appears to you. Every perceptual judgement is true in this sense, our perceptions do not last in time, they are unique and do not recur, nor does anything like that recur, even within a person's own experience. But then there exist at least two ways to interpret judgements that are not really about the object, but about the way it appears to the person making this judgement. One way of viewing things may be in terms of relations: I am judging the way the object is related to me (the wind is cold), and you are judging the way the wind is related to you (it is hot), and our observations do not conflict, although they concern the same object (the wind). A different way of going about things would be to say that the judgements do not concern the same object: there is the wind-as-it-appears-to-me, which is quite different from the wind-as-it-appears-to-you. There is no thing as the wind itself at all, there is no common object about which to disagree at all. If we take perceptual judgements as relations, we still do not escape from the problem of finding out what is this "it" that appears to me in one way, and in another to you? Can perception give insight to what this "it" is in itself, since its existence is beyond doubt (if something is changing into something else, then shouldn't there be the something that exists?)? Does "it" have any independent existence of its own? And maybe the object does exist, perhaps I also exist, but perception gives no information about that, since neither of these things is a relation. Things interrelating must have an intrinsic nature of some kind, which would explain how and why things relate as they do. But this cannot be known by perception. Then knowledge and perception cannot be identified, and there should exist things, which are not perceived, but known.7

To go back to the further explanation Plato gives about the secret doctrine, that the doctrine is about events or happenings and only changes exist, which can be either active or passive, and their interaction gives birth to the "twin offspring" of perceiving and perceived, which are both "slow changes". Plato does not define precisely what a "slow change" is, and it could be interpreted in at least two ways. The first (Crombie, McDowell) assumes that the eye and the stone are "slow changes"(active and passive), because the "fast changes" are said to be generated by the slow changes, and later said to be generated by the eye and by the stone. But if "slow changes" keep their changing in the same place, eyes and stones can change their places (how, otherwise would they approach one another? Maybe, it could be said, that it is not typical of them to change places). And there exists an alternative interpretation (of Sayre) that the "slow changes" are not the same as stones and eyes, but are changes taking place within eyes and stones. Then the "fast changes", which are described as traveling between the eye and the stone, are generated by other changes occurring within them, and cannot occur spontaneously. This way it remains an open question: if seeing and color (whiteness, as the example of Plato goes) are movements in opposite directions and these movements we interpret as streams of particles, each particle itself should be regarded as something that undergoes a change (of position), but is not something that is a change. Yet the doctrine holds that everything is a change - that there exist only movements, but not things moved. Things are not to be qualified in any way.

At this point in the "Theaetetus" Socrates starts investigating whether a thing can be even said to be something (a stone, an eye), because there are just things which act or are acted upon: "The conclusion from all this is, as we said at the outset, that nothing I s one thing just by itself, but is always in process of becoming for someone, and being is to be ruled out altogether... And we must not admit the expressions 'something' or 'somebody's or 'mine' or 'this' or 'that' or any other word that brings things to a standstill, but rather speak, in accordance with nature, of what is 'becoming', 'being produced', 'perishing', 'changing'. For anyone who talks so as to bring things to a standstill is easily refuted. So we must express ourselves in each individual case and in speaking of an assemblage of many - to which assemblage people give the name of 'man' or 'stone' or of any living creature or kind"(157a-c). From here follow two things. The first is that we ought to say that the thing we perceive is a stone for me, or even that it is becoming a stone for me. For another person it can be something else and even I cannot say whether it will remain a stone for me. (Timaeus' answer here might be that it is a piece of space). Since there is no permanent "it", the word is banished, the same way as the words "something", "someone's", "my", "this", "that" are banished, because they bring to a standstill. We cannot say what is it that appears, we can talk only of appearing itself. The second point made here concerns the "assemblage" Plato talks about: it seems that this "assemblage" can happen to last for a period of time, though its individual members do not. A perceiver is then a collection of perceiving (seeings of whitenesses) in change, while perceived objects (as stones) are collections of fast changes of perceived (whitenesses). But how can an "assemblage" be a cause of the generation of the items of which it is composed? This way, it seems, that perceivers and perceived objects are collections of perceptions, perceivers and perceived objects are constructed from them (are, then, perceptions themselves "slow changes" which are supposed to cause perceptions?...).The only thing we know is that perceptions are changes (events, occurrings, happennings, comings-to-be, interactions between two persistent items that are not themselves events). But does this contradict Plato's view that perceptions are relations? If the only things that exist in their own right are the changes understood as events that are perceivings (or appearings), and the same events yield both physical objects and mental objects (minds) when they are collected in different ways (for each depends on its existence on the other and neither takes place unless the rays intermingle), then the "secret doctrine" could be said to be really about motions and changes that are relations.

Thus, every perception is true, "since what acts upon me is for me and for no one else, I, and no one else, am actually perceiving it" , and "Then my perception is true for me, for its object at any moment is my reality, and I am, as Protagoras says, a judge of what is for me, that it is, and of what is not, that it is not"("Theaetetus", 160c), and perception is relative. Nothing ever is, but is always coming to be, and everything is an offspring from motion, change and blending together. The only things that exist in their own right are changes, and what is considered by us as something stable is just a collection of these changes. The changes that come to be are made known to us by our perceptions.

The realm of becoming, consisting of experience-objects and opposed to the realm of being, consisting of the Ideas, are once more contrasted in the "Timaeus": "First then, in my judgment, we must make a distinction and ask, What is that which always is and has no becoming, and what is that which is always becoming and never is? That, which is apprehended by intelligence and reason is always in the same state, but that which is conceived by opinion with the help of sensation and without reason is always in a process of becoming and perishing and never really is" (27c-28a). 8 There is a great difficulty to identify an object for what it is, since all perceptible objects are interchangeable, and can be called all names, never being the same as themselves. What recurs in the flux of objects are images. There is a certain double aspect to them: on one side, as far as they are in flux, then nothing can be said of them, they are in the process of change at the moment the statement is made. On the other side objects that occur are Images of the Ideas and as such, they can be identified according to kind. Only space, holds Plato here, gives a field across which images appear, but it does not give continuity to the images as they change. This way to say that something is fire is to attribute fieriness to it perpetually (we don't say that something is something, but that it is "suchlike"). Because of the everlasting flux of elements there is nothing in this world , which can be properly said to be fire, and all we have is space, which may be called "inflamed", as it receives imprinted on it an image of what really is fire - i.e. of the Form. Sensible things change, and Forms do not and "to be" in the present is to be used for only what is eternal and completely changeless.9 *

Does Plato believe in the theory of flux he sets forth? And which theory of flux exactly does he defend in his dialogues?

In Plato's later dialogues there are three passages which contradict the distinction made between being and becoming. In the "Sophist" Plato argues that the category of "being" must include entities which belong to the category of "becoming" ("And you say that we have intercourse with becoming by means of the body through the sense, whereas we have intercourse with real being by means of the soul through reflection. And real being, you say, is always in the same unchanging state, whereas becoming is variable" 248a), for a power of acting and being acted upon belongs to "becoming", and neither of those two powers is compatible with "real being" (248c). But knowing and being known is an action, an experiencing of effect (or both) - knowing is acting on something, and being known is acted upon by it, and by being known by the act of knowledge reality is changed owing to being acted upon. Thus, we cannot say that reality is changeless (248d-e). The philosopher, who values knowledge should refuse to accept the doctrine that all reality is changeless or the doctrine that reality is changing everywhere: "Like a child begging for 'both', he must declare that reality or the sum of things is both at once - all that is unchangeable and all that is in change"(249d).

Another passage that contradicts the distinction between the two realms of "being" and "becoming" is found in the "Parmenides": "And 'coming to be' and 'ceasing to be' mean, as we said, nothing else than acquiring being and losing it. But a thing which has nothing at all to do with being cannot acquire or lose it" (163d).

Being and becoming cannot be separated, there are no two categories at all, holds Plato in the "Theaetetus", giving the refutation of the flux-theory on the ground that becoming must include entities that belong to the category of being (181b-183c). Plato here first restates the flux doctrine as everything being in change - both altering and moving in place, as a change of position and a change of quality (on the example of a thing that is staying in place and growing older, or turning black from white, or hard from soft), and goes on from here to build up his argument against the flux doctrine. This is how it is stated: "...Since, however, there is nothing constant here either - the flowing thing does not flow white but changes, so that the very whiteness itself flows and shifts into another color, in order that the thing may escape the charge of constancy in that respect - can we ever give it the name of any color and be sure that we are naming it rightly?... And again, what are we to say of a perception of any sort - for instance, the perception of seeing or hearing? Are we to say that it ever abides in its own nature as hearing or seeing?" (182d).

There are two views on what is actually rendered absurd in this statement. The first interpretation (Crombie, McDowell) is that we couldn't even say what color something is becoming, unless we could say what color it is. If the only thing we can distinguish about something is a flow of color, or a flow of size, or a flow of shape, but not a particular color, size or shape, then we cannot say that the thing has any characteristics, i.e. the object is absolutely indescribable. Plato does agree, that it is not absurd for a thing to be perpetually changing its place or its color. But then, can a thing be continuously changing all of its characteristics? Need a thing have any most specific or determinate characteristics over time? Or, if not, need it retain certain most general characteristics over time? Are there patterns of change, a specific mode of changing that a thing follows? An entity which exists over time must retain some characteristics if it is to be identifiable and to have characteristics predictable of it. But these characteristics could be patterns of change.

On the ground of the flux doctrine all becoming predicates are legitimate (an object can remain for a while something that is becoming white). But if we hold the view that each thing is in change in absolutely every respect, it cannot have stability even in relation to its flow. We cannot even say that something is flowing over time, because this is a form of stability, and no stability is possible. This way, every characteristic is flow in the flux theory, but a flow by necessity must last for some time. An object must retain the characteristic of flow over time, but no characteristic can last in time, for it is stability. It follows that an object cannot have any characteristic at all. But then, there cannot be any object that has no characteristic at all. An object cannot be even flowing towards a stable form, because that too would be a stable flow. There is no flow characteristic an object could have, if it is always changing in every way, and not even a flow of a flow (that would be only shifting the problem to a meta-level, but would not resave it).

Another interpretation of this passage argues that Plato here holds that what changes is not that the flowing thing is white (Bolton). What changes is that it flows white . It is the "whiteness", referring to the white flow, that is the characteristic that should change. Plato is then trying to defeat the Heracliteans on their own ground. Plato states: "All things, by your account, are in a perpetual stream of change... With both the kinds of change we distinguished - both moving in place and altering? ...Well now, if they only moved in place without alteration in quality, we should be able to say what qualities they have as they move in that stream, shouldn't we?" (182c). To not change quality here is to be stable flowing in a certain fashion. It doesn't seem to contradict the flux theory in its moderate variation: it is only the extreme doctrine that is rejected. It remains valid, that an object can retain over time only becoming characteristics, or flow, as a contrast to the extreme view that there are only changes, and an object cannot retain over time whatever characteristics, not even the stability of its change.

Plato's theory of reality and change seems contradictory and undergoing certain changes itself throughout the Dialogues. But what is important is that Plato retained his theory of reality degrees, based on the distinction between being and becoming, though he does not follow the extreme version of the flux doctrine. Since the realm, perceived by our senses, the realm of single things, is unstable, since it is a realm of emerging and perishing things, which appear to be different all the time, it cannot carry the meaning which gives identity to the things in the world. The reality of the perceived cannot play the role of the reality without the existence of which objects would be falling apart all the time. Only something which is not depending on sense-perceptions could always be identical to its own self and sufficiently general as to apply to all of the diversity of things, but at the same time sufficiently concrete in order to exist alone and be well defined. The Forms are not a consequence of our minds, but exactly vice versa. Only the Forms are the "real" reality, the "real" truth about things. They are the essence, which is grasped by the mind's eye, the causes of things and their beginning, because the chaos of the flux-world is structured only through its relation with the Forms, and "You would loudly proclaim that you know of no other way in which any given object can come into being except by the participation in the reality peculiar to its appropriate universal..." ("Phaedo", 101c). Plato's answer remains that the only everlasting, neverchanging, existing self sufficiently, out of space and out of time reality are the Forms and nothing else.

1993, Waterloo