The possibility of philosophical spiritual animals. Though the nature and function of the philosophical level of neurological organization is clear, the inevitability the philosophical spiritual stage of evolution is still in doubt, because it is not yet clear how epistemological philosophy can be tried out as a random variation on the arguments of the rational spiritual stage and tired out in a way that allows it to be selected for the power it affords.

Culture must evolve long enough at the rational spiritual stage for a second level of forensic organization to be tried out as a random variation, and that means that some rational subjects must be free enough from the immediate demands of survival to exchange arguments over many generations. It also requires writing and a love of argument — writing in order to bridge the gap between generations, and love of argument to spend the time and effort required to sort out which arguments yield the most coherent world views. These conditions can be provided in what is called civilized society. Thus, in order to show the inevitability of the philosophical spiritual stage, I need only show the inevitability of civilization, for we can assume that among the variety of civilized spiritual animals that would come to exist on the surface of a planet if they were inevitable, there would eventually be some in which epistemological philosophy would be tried out as a random variation in cultural evolution.

There is, as it turns out, an aspect of spiritual animals that would make civilized society inevitable, because the social aspect of spiritual animals can also have a structure that is capable of several levels of part-whole complexity. That is, levels of social organization would cause a series of stages of social evolution, and assuming that civilization is one of these levels, civilization would have an essential nature just like what evolves at any stage of evolution. And the overall course of evolution would be determined by how the series of stages of social evolution combines with the series of stages of cultural evolution that we have been discussing (that is, the spiritual stages of evolution that we are following, primitive, rational and philosophical, respectively).

Even in civilized society, however, epistemological philosophy is unlikely to be tried out, unless the more obvious ontological approach to philosophy has been tried out and found wanting. The inadequacy of religious attempts to unite the arguments of rational level culture in a compelling way is the only plausible reason to try constructing linguistic structures with a higher level of forensic organization, and since the world seems to be a natural world, the initially most plausible way of explaining everything in the world will be to identify the substances constituting it. Thus, the evolution of epistemological philosophy requires the culture of a civilized society in which dissatisfaction with religious explanations has spurred the development of a primitive form of ontological philosophy.

 There was, as it happens, a spiritual animal at the civilized social stage of evolution in which ontological philosophy was tried out, namely, ancient Greece, and that is where we will find the origins of epistemological philosophy.

Stages of social evolution. Spiritual animals have a social aspect, as well as a cultural aspect, as part of their essential nature, and both are structures of the spiritual animal as a whole, though these structures are fundamentally different from one another. These aspects arise from how language is used to guide their behavior. The original social aspect is the fact that the members of spiritual animal are in continual linguistic interaction with one another, and the cultural aspect is all the linguistic structures that are, in principle, complete in the brain of each members. The use of language to distribute a plan is what coordinates the behavior of the members of spiritual animals in social level behavior, and higher levels of organization in the cultural structure distributed by language is what causes the stages in the evolution of spiritual animals that we have been describing. At the rational stage, as we have seen, the shared plan takes the form of mutually accepted rules (or arguments) governing social roles, and the social level behavior is just the existence of institutions.

Though institutions that persist over long periods of time may be considered a kind of “social structure” of the spiritual animal, they are not the kind of structure that can serve as a structural cause of the spiritual animals behavior. Institutions do not give the spiritual animal a geometrical structure that does not change over time. They give the social aspect of spiritual animal a spatio-temporal structure, for institutions are just a form of social level behavior that is generated by the cultural aspect. (This is, perhaps, most obvious in the case of economic institutions. Although they involve patterns in the interactions of members, they also include the social level behavior by which spiritual animals extract free energy and other resources from nature, just like any animal acting on other objects in space.)

Spiritual animals are, as we have seen, different from multicellular animals (with nervous systems), because their animal behavior guidance system is not constructed by coordinating the behavior of the lower level organisms. Since its behavior is guided by the exchange of linguistic representations, no social structure is needed, except continual linguistic interaction, and its animal behavior guidance system also serves as its biological behavior guidance system for this social level animal.

The reason for calling this kind of social level animal a “spiritual animal” was that, unlike all other animals, it does not need any unchanging geometrical structure as a whole. The spiritual animal has no body except the bodies of its members. That gives the spiritual animal enormous power. Since the parts of its body can have any geometrical structure that is possible for objects in space that move as time passes, there is no limit on the spatial aspects that its animal behavior can have in acing on other objects in space. For example, when members coordinate their behavior to herd deer into a trap, they are like a giant animal in relation to their prey.

However, the lack of any essential geometrical structure to the spatial aspect does not mean that spiritual animals cannot acquire a geometrical structure of a kind that can serve as a structural cause of social level behavior.

There is a way in which institutions can sustain a geometrical structure under the social aspect that would serve as a structural cause for helping to generate the behavior of the spiritual animal. That is the institution of property, for when it includes the ownership of parcels of land, it can impose an unchanging geometrical structure on the spiritual animal as a whole. As members observe the rights and duties defining the social roles of property ownership, the spiritual animal has, as least, an unchanging geographical structure.

Let us use the term ,“social structure,” to refer to what is unchanging about the geometrical structure of spiritual animal, reserving the term, “institution,” for patterns in the behavior of the members of spiritual animals that do not necessarily have an geometrical structure that does not change over time. Thus, social structures would include the geographical structures of spiritual animals with the private ownership of land. But there are also other kinds of social structures, as we shall see, which depend on a geographical structure, and they can, in a sense, be considered social structures with a higher level of part-whole complexity.

To be sure, nomadic spiritual animals also have a structure under their social aspect. But apart from its institutions, it is merely how the members are merely in continual linguistic interaction with one another, and so, let us speak of nomadic spiritual animals as having only a “spiritual social structure,” the minimal structure required by the essential  nature of spiritual animals.

Levels of social structure. The possibility of spiritual animals having social structures of a kind that can serve as structural causes of social level behavior means that stages of social evolution are possible. If there is a series of levels of part-whole complexity involved in social structures, they can evolve in only one order, from one level to the next. And their evolution will be inevitable, if in each case, the higher level social structure is both functional and possible — that is, “functional” in the sense of generating social level behavior that helps control conditions that affect the spiritual animal’s reproduction, and “possible” in the sense of being a possible random variation with such effects, given the institutions that are evolving in the spiritual animal. Thus, if they lead up to civilization, they will show the inevitability of philosophical culture. Thinking of social structure in this way, there are at least three stages of social evolution during the rational spiritual stage — and another stage of social evolution that is eventually made possible by philosophical culture.

Nomadic bands. This is the stage of social evolution at which we left the history of the evolution of rational spiritual animals, the stage whose limited resources and leisure posed a problem about the possibility of philosophical culture. Though members of spiritual animal are in continual linguistic interaction and they generate institutions as social level behavior, they do not have a geometrical structure as a whole, because they are always picking up and moving from one place to another in order to hunt and gather food. Their size is limited (from twenty five to maybe as many as a hundred) by the amount of food that can be acquired in this way. This is the stage during which the cultural evolution of moral rules would lead most easily to equality among members.

Agricultural villages. When environmental conditions became favorable (it happened about 11,000 BC in the Middle East at the end of the last ice age), some nomadic bands would give up hunting and gathering in favor of agriculture. The cultural evolution of natural science in nomadic bands would afford them enough knowledge of the efficient causes involved in plant growth and animal behavior to try out such an economic institution. In addition to being possible, it would be functional. The use of agriculture would provide so much more food that it would be possible for a spiritual animal’s population to grow without it having to divide into smaller groups (though that would continue to happen by setting up colonies), and so it would be naturally selected because of the advantages of increased population in fighting wars. Though such rich, sedentary spiritual animals would be easy targets for marauding bands, they could muster armies and construct defenses to protect themselves.

As population is grew, however, an increasing division of labor would be required to grow plants and take care of animals, and the institution that would inevitably evolve to coordinate their behavior in this activity is property, that is, ownership by different members (families) of different parts of land in their territory. Though there would be public areas and roads connecting different parcels of land, private ownership of land would be an unchanging geometrical structure of the spiritual animal. It would usually be stable over long periods of time, since the simplest way to assign new members to parts of land is by inheritance from parents (though the kinship would have to be adapted to provide for inheritance as members married outside their family). And it would be the foundation for the evolution of a higher level of social organization: class structure.

Civilization. The advent of agriculture would make it possible to accumulate great wealth, not only food, but other objects, both natural and manufactured, that are useful in some way. In some cases, so much food would be provided so reliably that the population increase would make it possible to sustain markets, cities, great differences in wealth, and large standing armies. With population growth, it would become necessary to protect property from theft, to extract property from individual to sustain public institutions, including a government, judicial institution, army, and religious institution, and more generally, to coordinate the behavior of the members of a spiritual animal that was spread out widely over the land. Those spiritual animals that happened on a variation on the institution of property that could sustain a class structure would tend to be larger, more stable, and better able to win at war, yielding so-called civilization.

One form of class structure is slavery, that is, the ownership of other rational subjects. This variation would probably be tried out only when spiritual animals could sustain standing armies. One of the spoils of victory in war would be slaves, and a standing army would provide a sufficient level of coercion throughout the society to ensure the dominance of masters over slaves.

Another form of class structure is feudalism, with many varieties. In Western history, it involved a difference between two classes of society in their property rights to the same parcels of land. Both classes had the right to live on the land and consume what was produced there, but one class supplied the labor for agriculture and productive activities, while the other class coordinated their behavior and protected the direct producers from foreign armies. Feudalism was not mere coercion, because the lord and the serf shared the same culture, and the mutual acceptance of its arguments required them to acknowledge one another’s rights and duties. But members of different classes did not intermarry. Class membership was inherited.

There are other forms of class structure, some involving several castes on the model of feudal class systems, and slavery can be combined with them. But there is no need to insist on any order in their evolution. In all such spiritual animals, class structure is sustained by different forms of ownership of the land on which the members live and interact with one another. That is how their social level behavior is generated. Class structure involves a relationship of domination and submission between members of different classes, and that makes it possible to coordinate the behavior of an enormous population over the whole territory occupied by the spiritual animal. Such a class structure is a higher level of part-whole complexity in social structure, because the institution of property sustains a difference between two classes of member everywhere throughout the territory.

The class structure of civilized society would make their evolution inevitable. They would be naturally selected at the social level by success in war because of the advantage of having a large population. Thus, there are three stages of social evolution leading to civilization, making it inevitable. And since class structure makes it possible to sustain a large population over a wide territory, such spiritual animals can provide the condition required to try out a higher level of forensic organization as a variation on the arguments being exchanged at the rational stage. Civilizations will tend to provide the writing needed to retain arguments over many generations and communicate them over wide areas, because writing evolves, if only to keep track of the taxes required to support the government and its allied institutions. Since there will be some members with the leisure to argue, all that is required for philosophical culture to evolve is a culture that fosters the love of argument and has respect for the kinds of judgments about rational coherence on which cultural evolution depends — except, of course, for a random variation that tires out a higher level of forensic organization involved in philosophy. We will trace the career of that stage of cultural evolution. But first, let us consider a variation on the class structure of civilized spiritual animals that will be relevant in that career.

Capitalist class structure. There is another stage in social evolution that helps make the evolution of ontological philosophy possible. Though it is just a form of the class structure that is characteristic of civilized societies, it not only sustains an even larger population than slave or feudal societies, but also contains a form of evolution by reproductive causation that leads to the evolution of increasingly powerful ways of producing food and other useful objects. I am referring to capitalism. It can be tried out as a random variation, as we shall see, only in spiritual animals with a philosophical level culture, that is, where epistemological philosophy has evolved, and since capitalism plays an essential role in making ontological philosophy inevitable, it is relevant here to describe the nature of this social structure. Then we will go back and take up the issue about the evolution of philosophical culture.

Capitalism is an economic system in which processes of production are set up when capitalists put forth the capital to purchase labor power and other commodities required to produce commodities of some kind and they then sell them on the market for a profit.

Capitalism is a class system, because members of the spiritual animal engage in such processes of production in two, fundamentally different ways: as capitalists, who put forth their money to earn a profit, and as workers, who sell their labor power to the capitalist to earn a wage. But the class difference is not necessarily heredity, since individuals can change classes. Moreover, it is a relatively abstract class structure, because it does not necessarily divide the members of a spiritual animal into different classes. Particular individuals can occupy both roles as long as capitalists can hire workers and the necessary relationship of domination and submission exists.

Capitalism is a contained form of reproductive causation in which the “reproducing organisms” that evolve are processes of production, because they have both kinds of structural effects, reproduction and non-reproductive work.

Production processes are capable of reproducing themselves, because when the sale of the commodities returns more money than was invested in them, capitalists will invest not only in another round of production, but also in expanded production processes. That is, they reproduce in space as well as in time.

Processes of production also do non-reproductive work, like reproducing organisms, namely, producing commodities. Such structural effects can control the conditions that affect the reproduction of the process, because they can be sold on the market for a profit.

What makes capitalism a form of evolution by reproductive causation is the competition among capitalists for a profit on their investments. The reproduction of production processes by the reinvestment of profits expands their population, and since the market for any commodity is finite, some production processes will eventually be unable to make a profit and their reproductive cycles will come to an end. Thus, a natural selection is imposed by their own reproduction, just as in biological evolution, except that it occurs among production processes within a spiritual animal. That is how reproductive cycles of production processes add up over time in the “space” of a spiritual animal.

It is not just chance, however, which processes of production succeed in reproducing, because those capitalists who can produce the same commodities more efficiently (or more useful commodities just as efficiently) will be able to make a profit from selling their commodities and thereby reproduce their process of reproduction, while other, less efficient production processes will not. This form of natural selection will be called “capitalist selection.” Capitalist selection is made by success in reproducing, as in biological evolution, but it is made for returning a profit and, thus, for producing commodities more efficiently. Since capitalism constitutes the ontological cause for gradual evolution, the simpler reproductive global regularities, it is ontologically necessary that there will be change of production processes in the direction of natural perfection for both the processes of production and at the ecological level.

Capitalist selection means that there will be a gradual change in the direction of maximum holistic power for production processes of their kind. Their greater power is holistic, because when all possible efficiencies are made, all the conditions affecting their reproduction that can be controlled come to be controlled.

At the ecological level, the ecological niches to which production processes adapt are the various kinds of commodities that people are willing to buy (because they are useful in some way), and the “free energy” being tapped is the money people are willing to spend. At the ecological level, therefore, there are many different industries, and since in each of them, capitalists compete for profits, overall production in the spiritual animal changes in the direction of a maximum holistic power at the ecological level that parallels biological evolution. Production extracts as much money from consumers as possible while at the same time using the fewest and simplest factors to produce the commodities they buy.

There is, however, a new wrinkle in the case capitalist economic evolution, because natural science supplies new means for producing useful objects, and these technological changes not only make production of the same commodities more efficient, but also make it possible to produce other commodities (that is, other kinds of useful objects that people will buy). But it is a two-way street, because the evolution of capitalist production also develops the technology that natural science needs to progress in the discovery of the efficient causes at work in nature. Thus, there is an interaction between capitalism and natural science that propels the evolution of both, one by capitalist selection and the other by rational selection.

Like any stage of evolution, therefore, kinds of production processes start off simple, uniform and barely able to make a profit (controlling the conditions that affect their reproduction), but as a result of reproductive causation by capitalist selection, they become increasingly complex, diverse and powerful at making a profit. But considering how the evolution of technology combines with cultural evolution to propel the evolution of natural science, the gradual change of production processes in the direction of maximum holistic power is chasing a goal that is continually receding because technological advances are not merely increasing the efficiency in the production of the same commodities, but changing the commodities that must be produced to make a profit. It is as if the ecological niches were changing as the organisms adapt to them, though it can also be seen as capitalist production evolving maximum holistic power to satisfy the wants of the members of the spiritual animal.

Civilization must evolve before capitalism can begin, because competition among capitalists in the production of commodities requires a large market. And a class structure must already exist to put individuals in a social situations in which it is possible to try out the capitalist class structure as a random variation. That does not mean, however, that capitalism inevitably evolves from civilization. The institutions required for capitalism include not only a market for exchanging goods, but also a market for purchasing and selling labor power, and since such exchanges must be made with a great efficiency and reliability, the culture of the spiritual animal must include rather demanding rules about contracts. Moreover, the institution of property must not be so committed to feudal forms of land ownership for individuals to accumulate large quantities of capital. Such conditions are provided as we shall see, in philosophical spiritual animals. That is very likely the only situation in which capitalism can evolve for the first time. It is, in any case, the only kind of spiritual animal in which capitalism will have the evolution of natural science to interact with.

It seems likely, therefore, that history, the penultimate phase of overall evolution, is the result of an interaction between stages of social evolution and stages of cultural evolution.

Culture generates the institutions (mainly property) on which a civilized social structure depends, and civilization (class structure) provides the conditions necessary for epistemological philosophical culture to evolve.

Epistemological philosophical culture apparently provides the conditions necessary for capitalism to evolve in civilized society.

And capitalism is required, as we shall see, to provide the conditions for ontological philosophical culture to evolve from epistemological philosophical culture, because without the interaction between the capitalist evolution of production and the cultural evolution of natural science, natural science would not advance far enough for ontological philosophy to be convincing.

Pre-Socratic philosophy. Let us, therefore, set the stage for the first step in this sequence and explain how epistemological philosophy evolved in rational level culture. Its way is prepared, as I have suggested, by a primitive form of ontological philosophy, because the most obvious way to construct an arguments with a higher level of forensic organization than those rational level culture is on the basis of naturalistic understanding. From the historical record, we know that it occurred in ancient Greece. The Pre-Socratic philosophers tried out a kind of philosophical argument that was promising enough, despite being doomed by the lack of natural science, to become the model for epistemological philosophy.

Conditions were especially favorable in ancient Greece. Not only did the ancient Greeks have writing, a class structure to support a leisure class, and a love of argument, but there was a number of more or less independent spiritual animals with the same culture, located in different city-states. Since they traded by sailing across the Aegean Sea, they could exchange arguments, but their physical separation from one another made it hard for any one city state to completely dominate all the others, as happened in other early civilizations, such as Egypt and Babylonia. Since there was no centralized government that could increase its power by suppressing the exchange of arguments, it was possible for culture to evolve freely. And as it happened, the ancient Greeks had great respect for argument and sound rational judgment.

The autonomy of city-states in ancient Greece indicates that they were independent spiritual animals. But there were periods in which these spiritual animals were united more like a single spiritual animal, for example, in the Persian wars early in the fifth century. On the other hand, there were also periods in which they were so independent that they were at war with one another, as in the Peloponnesian war in the late fifth century. This raises a general issue about the boundaries of spiritual animals.

The boundaries of spiritual animals. The nomadic band of language using animals is the original model for spiritual animals, but even before agriculture, the extent to a single spiritual animal was unclear, because nomadic bands were related in tribes and tribes could act as a whole, for example, in wars with other tribes. The capacity of spiritual animals to merge and divide makes their boundaries inherently less permanent than other organisms. But in general, the reality of the social level animal is manifest in the capacity of the members to act as a whole to control all the conditions affecting social level reproduction, and the extent of its population depends on how broadly the behavior of rational subjects are coordinated in generating social level behavior. Though this unity is most obvious in its original form, the nomadic band, it can still be seen in the nation state, where the institution of government makes territorial boundaries clear, for they are units that are responsible for everything done as a whole. Even there, however, boundaries shift, and in the contemporary period, nation states may be in the process of being obliterated entirely as spiritual animals slowly merge into a single, planet-wide spiritual animal.

The capacity of spiritual animals to merge and separate does not, however, show that they are not social level animals. What the shifting boundaries of spiritual animals show is that they have a spiritual nature, for their spiritual nature makes it as easy for them to merge with one another as to divide and reproduce. Thus, it may make sense to think of groups within contemporary complex societies as spiritual animals, when they normally act as a whole independently of other groups over long periods of time. Indeed, we might even think of spiritual animals as being quite local and transient, for that is what is suggested by the notion of individuals having a spiritual body, as well as a physical body, to pursue their goals. (That is, members of spiritual animals can be said to have spiritual bodies, because they can enlist friends and occupants of social roles to cooperate in the attainment of their individual goals, as a local and limited way of generating social level behavior.)

But the essential nature of spiritual animals can be seen most clearly from their place in the stages of evolution, and that suggests the capacity of spiritual animals to control all the conditions that affect their reproduction is as important as their capacity to act as a whole. The power that is maximized by reproductive causation is holistic, and so the natural perfection that determines what is good for them has to do with the unit that has the final authority to act in every way for the members, that is, the government. It is in the state, therefore, that the spiritual animal exists most completely.

Pre-Socratic philosophy began about 600BC when Thales argued that everything is water. As we should expect, it began with a dissatisfaction about religious explanations. The Pre-Socratic philosophers did not want an explanation by the motives or actions of gods, spirits, or any other unseen beings with a nature like their own. Instead, they were looking for another kind of cause, the simplest assumption needed to explain nature. They called it the archê, which is variously translated as “first principle”, “beginning”, “origin of things”, or simply “first”.

At the beginning, the ontological way of providing an archê was at least as obvious as the epistemological. It is clear that what most of the Pre-Socratics were seeking as an archê was the substance that would explain everything in the world, and everything about the natural world, including change and diversity. They tried out various conceptions of material substance and various ways in which such an archê could explain nature.

Thales’ theory that the basic substance is water gave rises to other views during the first phase involving the Ionian pre-Socratics. Anaximander held that the basic substance was the apeiron, or the “unlimited, suggesting that substance is substratum in which opposite properties compete to occupy, as if it were a disputed territory. Anaximines argued that it is air, because then condensation and rarification could explain the change in properties and the diversity of kinds of substances.

Their attempts to explain the natural world by material substance makes it clear that the Ionians were giving an ontological explanation of the world, but another strain of Pre-Socratic philosophy explored the epistemological alternative, at least, in a primitive way. The Pythagorean philosophers responded to Ionian philosophy by trying to explain the natural world as constituted, not by material substances, but by numbers. Numbers are the concepts established in imagination with the evolution of the behavioral schemata for counting (because the same covert behavior of assigning one word in the unchanging sequence of words for each object would work regardless of the kinds of objects being counted). Numbers as abstract entities are known through reflective understanding, not naturalistic understanding, because they are units in the linguistic structure of the spiritual animal under its cultural aspect, and the peculiar nature of the knowledge we can have about numbers was part of the mystical ceremonies on which Pythagoreans based a religion. In any case, they took an object known by reflective understanding to be the first cause underlying the world, though numbers were associated with geometrical structures as a way of showing how they could explain natural phenomena.

In a second phase of pre-Socratic philosophy, problems about the nature of ontological explanation emerged in the form of a dilemma acted out in the choice between Parmenides and Heraclitus.

Parmenides argued that, if the world is to be explained by a single substance, change must be an illusion. As he put it, “What is, must be, and what is not, must not be.” This is a way of describing the temporal nature of substance, that is, as a self-subsistent entity that can neither come into existence nor go out of existence, but is permanent. That Ionians assumed that the archê is a single substance, and Parmenides was pointing out that, if so, there can be no change, because there is nothing in the world to come into existence or to go out of existence over time. Thus, he insisted that what exists is the One, or Being, and he conceived of its as an unchanging sphere of matter, for he realized that for any parts of it to be separated from any other parts, there would have to be something else that exists between them.

What seems to come into existence and go out of existence over time are properties, and Heraclitus explored the other horn of this dilemma. He also accepted the Ionian assumption that what explains the world is a single, first principle, but instead of taking it to be substance, Heraclitus took it to be change itself, that is, the coming and going of properties from existence. He called it “fire,” but his paradoxical pronouncements about the archê make it clear that fire was just a symbol for the changing properties that we perceive in nature. He said, for example, that one could, and could not, step in the same river twice. One can step in the same river twice, because things do seem to be permanent. Change is regular, being governed by Logos (or natural laws of some kind). At the same time, one cannot step in the same river twice, because the water constantly changes as it flows. The river is probably a metaphor for objects of any kind. Permanence is an illusion, because objects that seem to be unchanging are actually just a flow of properties, each existing only at the moment. That is, Heraclitus would insist that you cannot even stand on the same river bank twice.

An inherent defect in the very nature of the Ionian explanation was surfaced by the dilemma that Parmenides and Heraclitus posed. The Ionians explicitly wanted to explain the change and diversity in the natural world by an archê, a single, first principle. But if that archê is substance, then nothing exists to explain the change and diversity. And if change itself is the archê, then there is no substance. (There is nothing but transient, changing properties.)

A third phase of pre-Socratic philosophy discovered what was required for ontology to be explanatory. The solution to the dilemma was to postulate more than one kind of basic substance and explain change and diversity by different combinations of those substances, though there was a disagreement about how many basic substances there are.

Empedocles postulated four kinds of substances, earth, air, fire and water, and since these “element” were assumed to have different kinds of properties, it seemed that the change observed in objects could be explained by their mixture and separation. And different kinds of object could be explained by different proportions of the basic elements constituting them. Though Empedocles just assumed that his elements were able to move in the ways required to mix and separate, he explained why they mix and separate in the regular ways they do by postulating two forces, love and strife. Love drew different kinds of elements to one another, mixing them, and strife repelled them from one another, separating them.

Anaxagoras insisted that there are infinitely many different kinds of basic substances, or what he called “seeds,” and infinitely many seeds combined in each observable object. He explained change and diversity in the same way as Empedocles, and the difficulty of explaining the enormous range of the diversity and different kinds of change without only four substances that led Anaxagoras to increase the number of basic substances so profligately. In any case, he recognized that this mode of explanation required him to postulate a force to explain why change takes place the way it does, but instead of love and strife, he postulated mind (nous).

The need to postulate infinitely many different basic substances to explain what is perceived in nature all but renounced the Ionian attempt to find an archê, a first principle, but other problems with this kind of explanation were also pointed out by Zeno, a student of Parmenides. One reason for holding that the parts of ordinary observable objects are infinite is that they are always divisible. But Zeno pointed out that an object of finite size cannot be made up of parts that are infinitely small parts (like Anaxagoras’ seeds), no matter how many such parts there are. And if the parts have finite sizes, there cannot be infinitely many of them. Furthermore, there were problems with the basic mechanism of change presupposed by both Empedocles and Anaxagoras, because they must assume that the basic substances can move in order to explain how they mix and separate. The basic problem is that motion must be made up of momentary parts, but if there is no motion at each moment, there is a similar problem about how all the moments can constitute motion.

In the final phase of pre-Socratic philosophy, the attempt to solve these problems led to the discovery of the best ontological explanation of the natural world. All the change and diversity in the world could be explained much more simply by postulating just two kinds of opposite elements, or substances.

Leucippus and, his student, Democritus argued that the natural world is made up of atoms and the void. The atoms were bits of matter with infinitely many different sizes and shapes, and though scholarship is divided on this point, they could have believed that the void is an opposite kind of substance that contained them. They insisted that both elements must be postulated in order to explain motion, because without the void, there would be no room for atoms to move. And if atoms can move, then everything that happens can be explained as simply the result of how their geometrical structures interact with one another, for example, like a hook and an eye to bind with one another (that is, structural causation).

(Many scholars hold that the ancient atomists did not believe that the void was supposed to be a substance that exists everywhere and coincides with the atoms where they are located. Instead, they insist, the void was assumed to exist only at those locations where atoms do not exist. That is, however, to treat the void as a very subtle kind of material substance that can flow around atoms as they move. That makes atomism more like what is later called “plenum theories,” which deny that there is any void. Furthermore, that interpretation makes it hard to see how the ancient atomists could think that the void explains how motion (and, therefore, change) is possible.

Atomism gave rise to another problem, however, which made it incredible. It replaced material substances whose essential natures were defined by qualitative properties, such as hot and cold, dry and wet, and various colors, with material substances whose essential natures were defined by their geometrical structures. That was attractive, because it was possible to explain change as determined necessarily by the motion and interaction of atoms, avoiding the need to postulate other forces, such as love and strife. But it required some explanation to be given of the qualitative properties that objects appear to have, and there was no plausible alternative to recognizing that they depend on the subject, or as Democritus put it, they are “by convention.” Thus, atomists gave up naïve (or direct) realism about perception in favor of critical realism. But that merely underlined the need for an explanation of the nature of the subjects who know about the world. Though Democritus insisted that the motion and interaction of atoms in the void explains the capacity for reason, by which subjects can recognize the necessity about what happens in a world, but his way of explaining reason was to hold that there are special, spherical atoms in the brain. Spherical atoms are as incapable of explaining these appearances as they are unable to explain the capacity to understand necessity in the natural world.

Even though Pre-Socratic philosophy discovered the nature of substance, recognized how substance could explain the world, and even discovered that spatiomaterialism is the best ontological-cause explanation of the world, it did not establish ontology as a way of doing philosophy. It did provide a model for the attempt to construct arguments with a higher level of forensic organization than rational level culture, for it not only rejected religious explanations, but also found a kind of explanation that could promise, at least, to explain everything in the world in the same way. But such a complete explanation must also explain the existence and nature of beings who are able to understand the first level arguments of rational culture. Though Democritus’ theory about spherical atoms can be seen as pointing to neurological mechanism, it is a far cry from explaining how nothing but the motion and interaction of atoms in the void is able to understand the motion and interaction of atoms in the void. And though Democritus gave a plausible explanation of goodness on the assumption that pleasure is the ultimate aim of all behavior, that did not explain goodness in the way Socrates wanted, and in any case, talk about pleasure merely focused attention of his lack of an adequate explanation of the qualitative aspect of experience (that is, consciousness). But ontological philosophy could not do better than Democritus until the evolution of natural science, when the discovery of the details about how “atoms” move and interact at the micro level made it possible to trace out the course of evolution and discover how the brain works.