10
DIOGENES OF APOLLONIA AND MATERIAL MONISM
WE HAVE COME almost to the end of the story, and yet there remains one problem that we have not addressed. Where did the notion of Material Monism that is so prominent in Aristotle and the doxographical tradition arise, if not from the early Ionians? How did it come to be so prominent in the historiography of early philosophy without its being an important feature of that philosophy? Could it really be only a mirage? Certainly Aristotle did not invent Material Monism. By taking a closer look at the appearance of MM, we can form a clearer picture of how it came to be thought of as the original approach of Ionian philosophy. In this chapter I shall argue that the source of MM is Diogenes of Apollonia, a figure who has occupied an anomalous role in accounts of Presocratic philosophy. Though most assessments of his contribution have assigned him a minimal significance at best, we shall find reason to see him as an important figure.
10.1 Diogenes in Modern Accounts
Diogenes was a member of the last generation of natural philosophers to have an impact before Socrates. His activity can be dated by the fact that his cosmology is parodied by Aristophanes in the Clouds, performed in 423. Diogenes portrays air as the single source of all things. Thus he is obviously influenced by Anaximenes’ theory. He clearly holds that all things not only arise out of air but are now air, that is, forms or manifestations of air as it appears in different guises. Thus he holds Material Monism. According to orthodox interpretations, he is asserting the same theory that Anaximenes introduced in the previous century—though it is now obsolete. Thus Diogenes can be seen as a throwback to an earlier time, someone who has missed the point of Eleatic criticisms and who does not appreciate the need for a pluralistic theory to answer them.
Another approach to Diogenes is to see him as attempting to combine several points of view. Theophrastus seems to support this reading:
Diogenes of Apollonia, who was one of the last to study this kind of thing, wrote mostly in a composite manner, following either Anaxagoras or Leucippus. He too said the nature of the totality is air, which is boundless and everlasting, from which, by condensation and rarefaction and change of affections, the form of everything else comes to be. Theophrastus reports these views of Diogenes, and the treatise that has reached me, entitled On Nature, clearly makes air that from which everything else comes to be. (Simplicius Physics 25.1-8 = A5)
The word I have translated “composite,” sumpephô rêmenôs, is often rendered “eclectic,” and consequently Diogenes is treated as an eclectic philosopher. The Greek term does not quite mean “eclectic”—it is typically used of things jumbled together1—yet it at least suggests a lack of unity and cohesiveness. According to Simplicius, he was dependent on Anaxagoras and Leucippus at different points—not to mention Anaximenes for his ultimate insights. While Anaxagoras and Leucippus are more recent figures and hence more modern or up-to-date, they also have very distinct theories, both from each other’s and from Anaximenes’ theory. Hence the interpretation of eclecticism raises the question of how Diogenes could possibly combine such different viewpoints in a meaningful unity. He may be broad-minded and versatile, but Diogenes can hardly be a consistent philosopher if he draws on such disparate sources, at least if he combines them in an indiscriminate way. “By common scholarly consent, he was least as well as last” (Barnes 1982, 567).
The one positive notice that Diogenes has enjoyed in recent times has been that of Willy Theiler. In a dissertation originally published in 1925, Theiler looked for the sources of Xenophon’s argument for God from design.2 The trail led to Diogenes, so that Theiler could declare Diogenes the founder of teleological thinking in the Greek tradition. Theiler’s study has had a major influence on subsequent scholarship, and has raised Diogenes’ stock in the eyes of most scholars.3 Yet his thesis has serious problems. What should be most obvious is the lack of reference to Diogenes in Plato’s Phaedo—set in 399 when Diogenes’ work was well-known, or in Aristotle, in the context of teleological explanation.4 Plato and Aristotle consider Anaxagoras to be like a sober man among his contemporaries for saying that the world is arranged for the best. Yet they do not credit Diogenes for carrying the insight forward. Evidently they do not see him as making significant progress in advancing an idea they are sympathetic with. While there can be no doubt that Diogenes accepted teleological ordering in principle, it remains unclear how novel his use of it was.5
Finally, André Laks has studied Diogenes in his own right, attempting to view him as the creator of a unified theory, wherever he derived its elements.6 Laks has clarified many features of Diogenes’ theory and at last taken him seriously as a thinker. But he remains for Laks, as for most others, the inventor of the last Presocratic cosmology, and hence the end of the line.7
10.2 Diogenes in a New Light
Diogenes’ shortcomings according to modern historiography have resulted largely from his failure to present any new ideas; at most he appears to be recycling concepts and principles invented by others. If, however, as I have argued, Material Monism is not to be found in sixth-century cosmological theories, then Diogenes, by introducing the theory, has made a significant theoretical innovation. This point has been seen already by M. C. Stokes, who in many ways pioneered the viewpoint I have been arguing for.8 But it was buried in a chapter on “Miscellaneous Presocratic Contexts” in a section on “The Eclectics,” and it seems to have gone mostly unnoticed.9 Parenthetically, we should note that Hippon may have been another fifth-century Material Monist, who like Thales took water to be the source of all things—though our sources are ambiguous on this point.10 In any case, Aristotle judges him to be hardly worth considering, and we do not have sufficient texts by which to judge for ourselves;11 hence Diogenes remains the only figure to whom we can confidently ascribe Material Monism, and the only figure of his age to leave a significant mark on his contemporaries, resulting in a significant trail of evidence for modern students.
In the present chapter I have two different objectives: first, to show that if the argument of the preceding chapter is correct, Diogenes becomes a significant thinker with a new and important theory, one which became so influential that it eclipsed and obscured another similar theory, namely GST; and second, to provide some confirmation of the argument of the preceding chapters. It would be ideal if we could find in Diogenes evidence that he was consciously reshaping GST for his own purposes; unfortunately the texts are too exiguous to allow any such direct confirmation. What I hope to accomplish is the more modest task of making plausible connections among contemporary theories to show that Diogenes may reasonably thought to be a reviser of GST rather than a reviver of MM. In the present section I will explain the role of Diogenes entailed by taking GST as the standard early Ionian model of explanation. In the following section I will explore connections between Diogenes’ theory and those of other Presocratics in an attempt to provide historical evidence for the account arrived at ex hypothesi.
Suppose, then, that Ionian philosophy of the sixth century BC instantiates, more or less, GST. There was no instance of MM in pre-Parmenidean theories. In the wake of Parmenides’ criticisms of GST, there was no instance of MM: the cosmologies of the early or mid-fifth century are pluralistic theories positing elemental stuffs of some kind. Yet we find MM in Diogenes:
B2. My view, in general,12 is that all existing things are altered from the same thing and are the same thing. And this is manifest: for if the things presently existing in this world-order: earth, water, air, fire, and the rest, which plainly exist in this world-order, if any of these was different the one from the other, being other in its own nature [phusis] and not the same as it changed often and altered, in no way would it have been able to mix with another, neither would benefit nor harm <come to one from the other>, nor would any plant grow from earth nor any animal nor anything else come to be, unless they were so constituted as to be the same. But insofar as they are all altered from the same thing, they become different at different times and turn back into the same thing.
Here Diogenes gives us an argument that the existing things (eonta) of the world, including the four elements (recently identified by Empedocles), are really all the same thing. Often the existing things are thought of as the basic realities; but here they cannot be, for they (or three of the four elements named) share a more basic nature. If they did not, Diogenes argues, they could not interact with one another for good or ill; there could be no causal interaction between them. We shall come back to his argument presently. For now the main point is his claim that all the different things of the world have a common nature.13
But what is that nature? It is air:
B4. Moreover in addition to these there are the following compelling proofs: men and the other animals live by breathing air. And this is their soul (life) and intelligence, as will be convincingly explained in this treatise; and if this departs they die and their intelligence comes to an end.
Air is the source of life and intelligence, as we may see by considering that when living things cease to breathe, they die and cease to be sentient. This same substance is the source of intelligence and control in the world:
B5 (beginning). And it seems to me that the source of intelligence is what men call air, and by this all things14 are steered and it controls all things. For this seems to me to be God, and to reach everywhere, to arrange all things, and to be present in everything. And there is nothing which does not partake of this.
Thus we can generalize the principle of life to be the power which controls and arranges the whole world.15
Diogenes makes two claims: (1) there is a single substance in the world, (2) which is to be identified with air, one of the existing things. Thus he is a monist whose one is a material reality, namely air. He is, then, a Material Monist. Assuming that he has no predecessor, we may recognize him as the first Material Monist, the inventor of an important and influential theory.
Clearly, Diogenes borrows from Anaximenes in identifying air as the principle of all things. But if Anaximenes is a pluralist rather than a monist, Diogenes is an innovator precisely in his first claim. Now whether Diogenes is aware of his theoretical difference from Anaximenes is not clear and, for present purposes, irrelevant to us. Whether he thinks of himself as simply following Anaximenes in his monism or whether he is conscious of his innovation, Diogenes is going beyond Anaximenes’ theory in his own construction. He is probably using the same considerations for the primacy of air as Anaximenes used, but his air is not just the original and generating substance, but the only substance.
What makes Diogenes think that there is only one substance in the world? The closest we can come to answering that question is to examine B2. There Diogenes argues that if two different existing things were not really the same, they could not causally interact with one another. The force of his argument may be seen by contrasting his position with that of a famous dualist whose main classes of existents are not the same. Descartes explains the real difference between mind and body:
And first of all, because I know that all things which I apprehend clearly and distinctly can be created by God as I apprehend them, it suffices that I am able to apprehend one thing apart from another clearly and distinctly in order to be certain that the one is different from the other . . . and, therefore, just because I know certainly that I exist, and that meanwhile I do not remark that any other thing necessarily pertains to my nature or essence . . . I rightly conclude that my essence consists solely in the fact that I am a thinking thing. . . . And although possibly . . . I possess a body . . . yet because, on the one side, I have a clear and distinct idea of myself inasmuch as I am only a thinking and unextended thing, and as, on the other, I possess a distinct idea of body, inasmuch as it is only an extended and unthinking thing, it is certain that this I . . . is entirely and absolutely distinct from my body, and can exist without it. (Meditation VI, trans. Haldane and Ross)
Here the fact that I can conceive of one thing without another, backed by God’s omnipotence, shows that two things with different natures or essences are really or metaphysically distinct. Mind is thinking, unextended thing while body is extended, unthinking thing. The two kinds of substance have nothing in common. Hence arise the two great problems of modern philosophy: how can mind know body, and how can mind and body interact? Ultimately, Descartes must have recourse to the omnipotence of God to assure an answer to the former. The difficulties of several centuries of wrestling with these problems attests to the difficulty of bridging the gulf between two kinds of substance different in essence. The problem seems to be not just that their essences are different, but that they are mutually exclusive and have nothing in common: one is unextended, one extended; one is thinking, one nonthinking.
The parallel with Descartes’ argument shows that Diogenes’ argument is perceptive and powerful. Yet, one might complain, the alleged existents that Diogenes has in mind—for instance, the four elements—have a good deal in common even if they are different in some properties: they are all extended, for instance. Thus we find a metaphysical basis for causal connection among the several elements. There is room here for a healthy debate. But the whole question of causal interaction seems to be new in Diogenes. It is not found, for instance, in Melissus.16 There is one Eleatic property Diogenes seems to have in mind: homogeneity, which Diogenes takes as a necessary condition for causal interaction.17 If two beings were completely other, they could not interact. Diogenes does not seem to be able to distinguish between two things that are different in part of their essence but the same in some respect. In any case, Eleatic thinking about natures seems to play an important role in his argument. We might think of his argument as a kind of argument that causal connection presupposes ontological homogeneity. Without a common likeness in the existents, they cannot interact. And the only kind of likeness that will support causal connection is sameness of nature or essence.
Diogenes’ argument in B2 (quoted above) seems to go as follows:18
D1
1. If two things interact they must have a common nature.
2. Existing things (e.g., the four elements) interact.
3. Hence, they have a common nature.
Diogenes argues for D1.1 by pointing out that if the existing things did not have a common nature, they would not be able to mix or affect each other. But we can observe that they do interact (2), so they have the same nature. From Descartes’ perspective, one billiard ball can move another because they have a common makeup, and more generally both are extended physical objects. Diogenes tacitly requires that they have a common matter. Of course there could be much controversy about how much is to be read into “common nature” in the argument. But at least Diogenes articulates a specific requirement for causation interaction, one that in some sense is vindicated by modern science: Newtonian bodies have mass and velocity and interact in ways determined by these properties.
The standard view of Diogenes is that he is reviving MM in the wake of Eleatic objections to cosmology. On this view, he is going back to an obsolete system and can offer his modern interpreter no fundamental insights. 19 Yet precisely how Eleatic objections defeated MM we are usually not told; in fact,MM seems to offer resources for replying to the Eleatics. On the present view,MM never existed before Diogenes wrote, and hence he alone is responsible for this important theory—important at least in the later tradition of interpreting the Presocratics. Diogenes could not be reviving MM, but at most revising a superficially similar theory, GST. He is, then, introducing an innovation, whether it is timely or untimely, progressive or vain. Whether Diogenes is consciously revising GST, or whether he thinks he is reviving MM with new and improved arguments, we cannot say on the basis of the evidence we have. But in either case, if the present analysis is correct, he is an innovator who changed the terms in which the original substance was understood and defended, drawing on an Eleatic conception based on a fixed and invariable nature or essence.
10.3 Diogenes in Historical Context
Thus far my interpretation of Diogenes is based on a hypothesis, namely that the early Ionians are followers of GST rather than MM. Now we must examine the interpretation in light of what we know about its historical context. Does it make historical sense? The first point to notice is that, according to Barnes (as discussed above),20 a strong point in favor of MM as the correct interpretation of early Ionian philosophy was the fact that the condensation-rarefaction entailed or presupposed MM. I have already argued against that claim. But we may point out that Diogenes himself does not make use of condensation in his account of air in the fragments, which clearly embodies MM. Instead, he uses another feature:
B5. And it seems to me that the source of intelligence is what men call air, and by this all things are steered and it controls all things. For this seems to me to be God, and to reach everywhere, to arrange all things, and to be present in everything. And there is nothing which does not partake of this. But nothing partakes of it in the same way as anything else does, for air itself and intelligence have many forms; for it is mani-fold, warmer or colder, drier or moister, more stable or more lively in motion, and many other differentiations are present in it, and countless differentiations of flavor and color. Furthermore, the soul of all animals is the same: air that is hotter than that which surrounds us, yet much colder than that around the sun. The heat of no two animals is alike (since not even the heat of different men is the same), but it differs—not greatly, but in such a way as to be similar. Nothing, however, of those things that are differentiated one from another is able to become exactly like the other without becoming the same. Thus since differentiation is manifold, animals too are manifold and many and unlike each other in form, behavior, and intelligence because of the multitude of differentiations. Nevertheless, all things live, see, and hear by means of the same thing, and all have the rest of their intelligence from the same source.
Here it is not the scale of density but the scale of temperature that determines the phenomenal character of air. Density is irrelevant, or perhaps only a parameter of heat. The relative temperature determines what the character of a thing is, apparently what species of thing it is, and even the individual character of a thing. Thus heat controls both the specific differentiation of a thing and the individuation of one particular from another. Diogenes does see air as undergoing variations on a single scale while determining its character, but the scale is not that of density. In this respect Diogenes is independent of Anaximenes and has a different conception of the mechanism of change from his predecessor. Diogenes Laertius reports that Diogenes of Apollonia uses density in his cosmology, but we cannot confirm this from the fragments.21
Air has special properties that make it causally efficacious. Speaking of air, Diogenes opines:
B7. But this seems plain to me, that it is great, powerful, everlasting, immortal, and much-knowing.
Air is great insofar as it is boundless; it is powerful apparently as controlling other things; it is everlasting and deathless because it remains through all changes; and it is much-knowing as the source of all intelligence. Some features imply the control or agency of air, and bring us back to the question of teleology.
The statement about teleology is found in B3:
B3. For it would not be possible without intelligence for this distribution to come about in such a way that it had a measure of all things, of winter and summer, of night and day, of rain, wind, and fair weather. And everything else, if one would take notice, one would find arranged in the finest way possible.
The world results from a balanced distribution of qualities. But this distribution presupposes intelligence. Diogenes seems to lead us from particular examples of balance in cycles of seasons, days, and weather, inductively to generalize a pattern in all cosmic events: there is order, implying intelligence. But where does the argument go from there? The most obvious step is to say that intelligence is found only in its bearer, air. Hence air is the source of order and direction in the cosmos.
If that is how the reasoning proceeds, it does not instantiate an argument from design, which argues from cosmic order to a divine source. That argument would go as follows (from Barnes 1982, 577):
D2
1. The world is organized in the best possible way.
2. Hence, there is an intelligent arranger of all things.
But we do not find evidence for a personal agent in Diogenes. His argument (as reflected in B4) moves from cosmic order to a particular physical source, air. Now it is true that for Diogenes the source is divine; but on the present reconstruction, that consequence would be a concomitant of the source’s being air. The argument seems to go as follows:
D3
1. The world is organized in the best possible way.
2. Something can be organized in the best possible way only by intelligence
3. Hence, the world was organized by intelligence.
4. Intelligence requires a physical principle.
5. The physical principle of intelligence is air.
6. Hence, air is the principle of the world.
D2 moves from an observation of order in the world to an individual agent, a personal deity who organizes it, in an argument for the existence of God from design. Diogenes’ argument D3 moves rather to some impersonal stuff that presumably distributes itself appropriately; the argument aims at demonstrating the superiority of air to other stuffs—it answers something like the Problem of Primacy. The argument is not an argument for theism, that is, an argument from order to a benevolent designer, but rather from order to a physical principle. Hence the explication of Diogenes’ argument as the prototype of arguments from design would fail.22
The present interpretation seems to be confirmed by the opening sentences of B5: the first sentence identifies the source of intelligence as air, while the second uses the divine attribute as a confirmation, rather than a conclusion of the argument. There is also a significant difference between Diogenes’ argument and Xenophon’s argument, that according to Theiler, is based on it, in the fact that Xenophon sees God as arranging the world for man’s sake (Huffmeier 1963, 136). Accordingly, we see Diogenes not as an innovative theologian so much as a cosmologist arguing for a certain physical principle as the arche.
Yet there is an important teleological dimension to Diogenes’ thought. Air is something that brings order to the world in an intelligent, apparently purposive way. The pluralistic systems, following Parmenides’ cosmology, had driven a wedge between matter and the forces which direct it. Anaxagoras’s Mind was distinct from his numberless elements, while Empedocles’ Love and Strife were distinct from his four elements. Although the separation of force and matter brought conceptual clarification, it raised new questions. What is a force apart from matter? How does it interact with matter? These questions are analogous to the problem of causal connection raised in B2. Diogenes could reasonably argue that by locating causal efficacy in matter, he was avoiding insoluble problems. His identification of air with the moving agency of the world was a much-needed integration that avoided a disastrous schism. He could also claim that his theory integrated thought and being in a way suggested by Parmenides but not realized in pluralistic theories.
Overall, Diogenes could claim that while pluralistic theories attempted to make sense of the world in terms of compounds or mixtures of elements, they in fact ignored the monistic principles that are the consequence of Parmenides’ Aletheia. What-is must, among other things, be homogeneous; pluralistic theories are by hypothesis heterogeneous. Diogenes makes room for plural manifestations of what-is, but these remain mere manifestations or phenomenal determinations—just as light and night might be thought of as mere appearances in Parmenides’ cosmology. In the present context, Diogenes’ theory makes remarkably good sense as a post-Parmenidean system, responding to the challenges raised by the Eleatics while accommodating the cosmological speculations of the Ionians. We are justified from a historical viewpoint in seeing his Material Monism as a robust theory that makes good sense as a response to the concerns of the later fifth century.
Diogenes’ ontology makes distinctions necessary to responding to the Eleatic challenge. On the one hand, he recognizes plural existents, eonta, including the four elements of Empedocles (B2). On the other hand, he argues that they must all have a single nature (phusis) in order to be able to affect one another. Although the concept of phusis is clearly older than Diogenes, it does not always have the connotations it does in Diogenes. Empedocles uses the term and its cognates to denote birth or coming to be.23 But clearly for Diogenes it has the sense of a fixed and unalterable nature, and essence in Aristotelian terminology. More significant, perhaps, is the fact that Diogenes associates existents with a special kind of change, heteroiousthai, apparently “alteration.”24 The same term appears in Melissus, leading Diller to think that Melissus is responding in part to Diogenes.25 Whatever the precise dialectical order, the terminology shared by the philosophers seems to witness to a more subtle appreciation of issues concerning change. The kind of change that existents undergo is not coming to be and perishing, but alteration or differentiation in properties. The one historical point we can make is that there is no sign of an analysis of change in the sixth century. Parmenides lists a series of suspect changes, perhaps for the first time making some sort of preliminary analysis (B8.40-41). As we have seen, reports of Anaximenes simply attribute coming to be to the basic substances, and Heraclitus explicitly views elemental change as coming to be and perishing—at the same time—since the coming to be of one element is the perishing of another.26 From a historical perspective, it is plausible to think that the attribution to existents of alteration arose only in the fifth century in response to the Eleatic challenge. We can remark in Anaxagoras and Empedocles a rejection of coming to be and perishing. There is no need for them to talk about alteration, since for them some sort of mixture is the mechanism behind phenomenal change. The only cosmologist in whom we can attest the language of alteration is Diogenes—giving some support to Diller’s interpretation. Whether he invented the distinction or not, he exploited it in his argument. And in that we can track an advance in discriminations over the sixth century.
One further distinction between Anaximenes appears at this point. If Aristotle is right (as I think he is not), Anaximenes accounts for (phenomenal) coming to be and perishing in terms of changes in density. Hence, he reduces coming to be and perishing to quantitative change, or, in Aristotle’s terminology, increase and decrease. But from what we have seen, we can observe that Diogenes accounts for phenomenal coming to be and perishing in terms of changes in temperature, a qualitative distinction. Hence, in Aristotle’s terminology, he reduces coming to be and perishing to alteration. Diogenes has some discussion of a void, and seems to have at least made room for an analysis of density.27 But he does not pursue this approach. Why not? I doubt that we can give any certain answer, but one possibility is that Diogenes saw Anaximenes’ theory of density as already compromised by Anaximenes’ belief that the elements are generated and destroyed. Furthermore, Parmenides had attacked Anaximenes’ strategy as incoherent.28 In any case, we see that Diogenes does not follow Anaximenes slavishly, and that he makes some significant reconsiderations of the Milesian’s theory.
There is no doubt that Diogenes is a Material Monist of the sort that Aristotle envisages. He gives a new and elegant argument for MM, what I shall call the argument from causal coherence: existent things could not interact unless they shared the same nature. In an era in which arguments are few, we should appreciate the ingenuity of this one. According to Diogenes, the connectedness of matter is evidence of its underlying unity. The phenomenal stuffs of the world result from alterations of a basic kind of matter, namely air. The causal argument and the mechanism of alteration are clearly inventions of Diogenes. He does not give a list of basic substances, other than to cite Empedocles’ four elements. He does not seem particularly concerned with enumerating the phenomenal stuffs, which are in any case only contingent and derivative beings. His basic concern seems to be to establish the primacy of air and to argue that all phenomenal existents are really air. In the pursuit of his argument, he points out that the world is arranged for the best, that this presupposes intelligence, and that air is the cause or principle of intelligence. If he enunciates less than an argument from design, he at least provides a coherent argument for Material Monism with air as the primary reality.
Does any of this prove that Diogenes invented MM? No. Yet we do see him as a perceptive respondent to the debates of the fifth century. He is not slavishly dependent on Anaximenes; he makes distinctions that seem impossible for the sixth century but appropriate for the fifth. If they are appropriate, they are in no way inevitable, and they show considerable insight in their own setting. They could, of course, be seen as refinements needed to bolster MM in the theoretical environment of the fifth century. But we may still ask if, in the absence of clear distinctions between nature or essence and attributes, generation and alteration, even reality and phenomenon, MM was possible. Perhaps in some intuitive form, but it is difficult to imagine a well-articulated theory.
I come back to Plato’s testimony of Anaximenes.29 He describes a theory of change according to which seven elements change into one another by generation, based on condensation and rarefaction, seeing it as providing a helpful description of our sensory observations. He invokes Anaximenes’ theory. We must assume he knew Diogenes’ theory that was so prominent in Aristophanes’ parody of his master. Yet he does not assimilate Anaximenes’ theory to Diogenes’. I must suppose that Plato saw significant differences in the two theories, and found the former useful as a preliminary account of how transformations occur in the sensible world. That he does not use the latter even in his account of teleological insights, in the Phaedo discussion, shows that he did not take Diogenes to have much to add to Anaxagoras. But clearly Plato could distinguish between the two theories on the basis of their ontological foundations, and I think we should too.
10.4 A New Theory of Matter
The reports that ascribe Material Monism to the early Ionians are suspect. On the present interpretation, the early Ionians adhere to GST. There is one original stuff, which is transformed by a process such as condensation into other basic substances which make up the cosmos. These stuffs can be transformed by an inverse process back into the original stuff. There is a kind of evolution of matter from one form to another which, when stabilized, supports the complexity of the world. In GST types of matter come to be and perish in such a way that the birth of one stuff is the death of another. Heraclitus identified this relationship as a basic principle of cosmology, and used it to suggest that only process philosophy can capture the insights of Ionian cosmology. GST provides the pattern of change in all or most sixth-century Ionian cosmology.
In the early fifth century, Parmenides criticizes cosmology following the pattern of GST. He criticizes the notion of coming to be and perishing, rendering the foundations of GST problematic. In criticizing traditional cosmologies he develops an alternative style of cosmology which does not rely on coming to be and perishing, but rather on the mixture of enduring stuffs. Picking up on the new style of cosmology, the pluralists develop a theory in which a plurality of stuffs, or elements, mix and separate in such a way as to account for the changes of the world. The new style of cosmology puts a strong emphasis on the distinction between phenomenal appearances and ultimate realities. Coming to be and perishing turn out to be mere appearances derived from changing relationships of invariable elements. The resulting theory is EST. The new theory distinguishes between the fixed natures or essences of real things and the changing properties of phenomena.
Finally, as a further consideration of problems of change and cosmology, Diogenes develops a theory according to which there is only one substance, air, which by altering or changing its states, can appear as a plurality of substances. His theory fits the characterization of Material Monism identified by Aristotle. It draws on the distinctions of essence and attribute, coming to be / perishing and alteration, reality and appearance developed in EST. But it draws also on the Eleatic property of homogeneity and the Eleatic insight that only one substance could satisfy the formal demands logic places on being. MM is thus a post-Parmenidean theory that seems possible only in light of Eleatic criticisms of matter and change. Hence MM is a neo-Ionian theory using Eleatic principles to modify and reconceive the principles of cosmology. The order of historical development is not MM, then Eleatic criticism, then EST, but rather GST, then Eleatic criticism, then EST, then MM.
On this account, Diogenes is an important innovator. He sees that the techniques of pluralism can be used to render pluralism obsolete: if phenomenal changes result from rearrangements of real but unchanging elements, why not make do with one element that undergoes complex changes of state? The only thing missing from this account would be an external cause to initiate change; but if we can locate the cause in the original stuff itself, then there will be no reason in principle why differentiation cannot be self-caused. Thus we can go beyond pluralism to a simpler theory. The resulting theory will be more true to its Eleatic roots than pluralism because it will posit only one kind of being; it will remain Eleatic in distinguishing between real unvarying being and phenomenal change, which will be only phenomenal and derivative. In this sense, Diogenes can claim to be more Eleatic than his pluralist predecessors, while yet preserving a robust account of cosmology. Diogenes emerges as an innovative philosopher with an interesting response to contemporary problems.
That Diogenes was seen as an important philosopher in his own time can be seen from Aristophanes’ response to him. In the Clouds of 423, air is taken to be the ultimate reality. A vortex motion accounts for many phenomena, and the gods themselves are rendered obsolete in the new theory. Euripides seems to react to Diogenes,30 and the Hippocratic treatise On Breaths also reflects the theory of Diogenes, as do other Hippocratic treatises.31 In his own time Diogenes seems to have been prominent—perhaps the most prominent philosopher after Anaxagoras.32 There is certainly no evidence to indicate that his contemporaries looked at him as a mere copycat or imitator of earlier theories. On the contrary, his popularity suggests that he was seen as offering the latest and most up-to- date theory of cosmology.
The modern judgment that Diogenes has little to offer results from a certain interpretation of the Presocratic tradition in which he appears merely to revive a theory refuted well before he wrote. This interpretation is, of course, directly dependent on Aristotle’s reading of Ionian philosophy, in which the earliest philosophers were Material Monists. If, then, the last Ionian philosopher was a Material Monist, he could have nothing interesting to offer the tradition by way of theoretical novelty. But if the account of the early Ionians I have offered is correct, then Diogenes was not reiterating a hackneyed and time-worn theory. Indeed, Aristotle’s very assumption that he was reiterating such a theory provides evidence for Diogenes’ influence: so completely had Diogenes’ theory dominated later thought that Aristotle could not read the early Ionians without projecting Material Monism onto them. The fact that Plato could distinguish the theories shows that the conflation of them was not inevitable. Yet that so astute an observer as Aristotle could conflate them shows how cogent the latter theory could appear. In a manner documented by McDiarmid (1953, 102ff.), Aristotle expanded a common theoretical principle, the primacy of air, into a common philosophy.
Let us return to the point where most histories of Presocratic philosophy begin. After introducing the Milesians as Material Monists, Aristotle makes specific attributions:
Anaximenes and Diogenes [of Apollonia] posit air as prior to water as the simple body that is most properly the source. (Aristotle Metaphysics 984a5-7)
Aristotle mentions Anaximenes of the sixth century and Diogenes of the fifth in the same breath. He sees no essential difference between the two, but merely an original monistic theory on the primacy of air and a restatement. On my interpretation, the original statement is that of Diogenes, and Aristotle’s attribution of the theory to Anaximenes conceals a major sea change in one-source theories. How did Aristotle get Anaxi-menes and his generation so wrong? He simply assimilated their theories to a much more familiar and, no doubt, well-articulated theory of the recent past.33 It would not be the first or the last time an able thinker had missed the historical difference between two superficially similar theories—and it may not have been the first time this particular identification was made.34 We must remember that the awareness of a Zeitgeist or, less portentously, a historical framework, was not even clearly articulated until the nineteenth century. We need not fault Aristotle for failing to appreciate changing historical perspectives in the infancy of history and the very beginning of the historiography of philosophy.
Nothing I have said in this chapter definitively proves that Diogenes was not a reviver of an old theory. But at least his complex response to philosophical questions on the one hand and the reaction of his peers to him on the other suggests that he played a different role: that he ingeniously revised and adapted an old theory to respond to the challenges of the fifth-century debate. The very success of Diogenes’ theory offers a diagnosis of how Aristotle could have misunderstood the early Ionians: he mistook the familiar theory for the unfamiliar, the articulate for the inchoate, the recent for the remote. If he did, his identification of the two theories is a conflation, and we are justified in departing from it. Diogenes turns out to be an interesting and even creative player in the debates of the fifth century.
1 See Laks 1983, 93.
2 Theiler 1965.
3 Laks 1983, xxvii–xxviii.
4 Plato Phaedo 97bff., Aristotle Metaphysics 984b8–22, 985a10–21; Huffmeier 1963.
5 Cf. Barnes 1982, 567. On the other hand, perhaps Diogenes assigns a much bigger role to teleology than Anaxagoras; according
to Laks 1993, 30, Anaxagoras’s “
noew is a teleological power not in the sense that it wants everything to be the best . . . but in the sense that it is capable
of handling the data in a sovereign manner, so that a complex cosmic order emerges from the least possible expenditure of
noew’ energy.”
6 Laks 1983, xxiii–xxiv.
7 The subtitle of Laks’s book is La dernie`re cosmologie presocratique; the title of Barnes’s chapter on Diogenes, “The Last of the Line.” Laks’s sense is somewhat equivocal: he rules out Democritus from consideration since Democritus is contemporary with Socrates (xix, n. 1).
8 Stokes 1971, 238–44.
9 Barnes 1982, 567, dismisses the view without referring to its author or arguing against it; Laks 1983, xxxii, n. 1, takes only passing notice; KRS ignores it.
10 DK 38; Hippolytus Refutation 1.16 = A3 identifies two principles, water and fire, and says fire is begott
en (gennimenon) by water, suggesting an instance of GST. On two principles cf. A5.
11 Metaphysics 984a3–5 = A7.
12 The phrase could mean something like “to describe the totality” (as Laks takes it).
13 Although McDiarmid 1953, 102–6, sees the connection Theophrastus, following Aristotle, makes between Anaximenes and Diogenes, he argues that “the air of Diogenes is no more an Aristotelian substrate than is that of Anaximenes” (105). True, it is not an Aristotelian substrate in the sense of prime matter, but it does in fact serve as the kind of concrete substratum for other properties that Aristotle envisages as being what some Presocratics posit as their ultimate reality. In other words, Diogenes does satisfy the conditions of MM.
14 Reading pAnta for pAntaw. See Perilli 1988–1989.
15 Barnes 1982, 574–76, argues that B4 and B5 concern psychology rather than cosmology; the ultimate reality is simply matter or stuff. But Simplicius has Diogenes’ book before him and is in a position to satisfy his own doubts about the matter (Physics 1528–9, 153.16–
17). Barnes’s interpretation would allow Diogenes to make a great conceptual leap (of the sort that seems to me anachronistic); on this interpretation he should be a much more significant thinker than Barnes himself is willing to concede (“a judicious eclectic,” 583).
16 I bracket the question of whether Melissus or Diogenes wrote first; they are in any case roughly contemporary thinkers.
17 Melissus reasserts this Parmenidean property, but does not connect it with causal efficacy per se: Pseudo-Aristotle On Melissus, Xenophanes, Gorgias 974a12–14 = A5.
18 Cf. Barnes 1982, 572–74.
19 Curiously, Cherniss, who rejected MM for the early Ionians, fails to see Diogenes as responding to Parmenides: “Hippo of Samos and Diogenes of Apollonia, who sought to derive the articulate world, the one from water, the other from air, are our chief witnesses to the fact that there were still men who could talk as if Parmenides never lived” (1951, 344).
20 Ch. 3, sec. 3.
21 “These are his views: air is the element, there are numberless worlds, and the void is boundless. Air by being condensed and rarified generates the worlds” (Diogenes Laertius 9.57 = A1).
22 Contra Theiler 1965, 15ff., cf. Barnes 1982, 576–79, who in fact recognizes the distinct emphasis of the argument but does
not distinguish it from arguments from design; Huff-
meier 1963, 134.
23 Esp. B8.1, 4.
24 Cf. Aristotle’s term for alteration, alloiosis, e.g., Categories 15a14.
25 Diller 1941, 366–67. Terminology provides only part of Diller’s evidence. The common view is that Melissus is earlier, supported, e.g., by Jouanna 1965. On the relation between Leucippus and Melissus, see also Klowski 1971.
26 B36, B76.
27 Diogenes Laertius 9.57 = A1; Aristotle On Respiration 471a4 = A31.
28 Parmenides B8.22–24, 44–45, 47–48.
29 Timaeus 49b-c, with sec. 3.4.4 above.
30 Trojan Women 884–9 = C2.
31 For other allusions in the Hippocratic literature, see DK 64C3, 3a, 3b; Jouanna 1965 shows how the Hippocratic Nature of Man criticizes Diogenes by using arguments inspired by Melissus.
32 Contrast Barnes, who concedes the fact that Diogenes is influential: “Such a reputation implies not stature and novelty but rather the reverse; it is unoriginal men who are thus representative” (Barnes 1982, 567–68). This seems to me tendentious.
33 Cf. Alt 1973, esp. 158: “Dabei kann kein Zweifel bestehen, dass man im 4. Jahrhundert hinreichend Kenntnis von ihm [sc. Diogenes] besass, weit mehr als von Anaximenes, und dass man sich im Peripatos fur ihn interessierte.” Her reference is to a time after Aristotle’s death, but the remark is true of Aristotle’s time also.
34 Hippocrates Nature of Man 1 refers to anonymous philosophers who derive the world from a single principle, whether air, fire, water, or earth. While we can assign Diogenes to air and possibly Hippon to water (n. 10 above), presumably we would have to connect early Ionians with the other principles: Heraclitus with fire and perhaps Xenophanes with earth; and if we have license to include early Ionians, Thales can be associated with water, Anaximenes with air. However, the Hippocratic author provides no real doxography, nor does he even name the philosophers he has in mind.