Matter. Naturalists believe that the world is just what is in space and time, and having seen that we should, if possible, believe that substances are in time in the sense of enduring through time, and that substances are in space in the sense of either being parts of space itself or coinciding with parts of space, the final issue to be settled is about the nature of the substances that coincide with space and endure through time. The simplest theory is obviously materialism, the belief that matter is the only kind of basic substance that coincides with space. But some phenomena seem to require immaterial substances as well. Our ontological causes would be more complex, if we had to postulate both material and immaterial substances as coinciding with space. But if the scope of our ontological theory is increased by postulating immaterial substances, it can be argued that there is a tradeoff between simplicity and scope that keeps the empirical method from requiring naturalists to accept materialism. In this case, therefore, we must decide whether there are any phenomena that require us to postulate immaterial substances as well as material substances. Let us set the stage by considering more carefully what materialism holds.

Materialism. Materialism holds that none but material substances coincide with parts of space. Matter comes in particular bits, and by "matter," we shall mean only substances whose behavior in space makes the laws of physics true. Thus, we assume that bits of matter move and interact in the regular ways required by the basic laws of contemporary physics and that there are enough different kinds of bits of matter to account for all the kinds of entities mentioned by those laws, from electrons and nucleons (or triplets of quarks) to force fields and photons. We will see what essential nature material substances that coincide with space must have for this to be true. (See Contingent Laws under Local Regularities under Change.) But given that it is true, materialism may also be called "physicalism," because the properties mentioned by the basic laws of physics are called "physical properties."

More abstractly, bits of matter are "basic" substances in the sense that they are the most elementary substances of their kind. Since each has an existence that is distinct from all the rest, they are "particular" substances. They are "concrete" in the sense that no bit of matter can be in two different locations at the same time. And they are "independent" of one another in the sense that the existence of one bit of matter does not, in general, depend on the existence of the others. That is, bits of matter can also move independently of one another and interact locally (though, as we shall see in Change: Forms of matter, there are some varieties of matter that cannot exist except in conjunction with matter of a different variety).

Since spatiomaterialism holds that bits of matter are in space in the sense of being contained by space as a substance, we shall take the basic laws of physics to be descriptions of regularities about their motion and interaction that result from their being contained by space, that is, as ontological effects of both space and matter. That is different from what spatial relationism assumes about the nature of matter, because spatial relationism can simply define the essential aspect of material substances by the basic laws of physics, implying that there is nothing more to be known about their natures and that bits of matter have an essential nature that is irreducibly temporally complex. But since we take space to be a substance, we are assuming that at least some of the regularities described by basic laws of physics can be explained ontologically, that is, by how the essential nature of space works together with the essential nature of matter, because of how matter and space coincide, to constitute those regularities. That is why we took spatiomaterialism to have a greater scope than spatial relationism: it could explain why bits of matter have spatial relations and how change is possible, rather than just assuming it. That is also how spatiomaterialism can promise to explain the truth of Einstein's relativity theories, as just mentioned. And it is how we will explain the other laws of physics in Contingent Laws under Change. Indeed, the possibility of such explanations is what we assumed by taking ontology to be a kind of explanation, rather than merely realism about science. But that means that spatiomaterialism must take matter to be a kind of substance that, working together with space as the substance with which it coincides, makes the basic laws of contemporary physics true.

In addition to explaining why efficient-cause explanations are true, moreover, ontological-cause explanations can also explain why rational-cause explanations are true, making all the kinds of explanations mentioned in Method parts of a single explanation of the world in the end and reducing the social sciences by way of natural science to spatiomaterialism.

Although spatiomaterialism implies that there is more to be known about the essential nature of matter, what is relevant for present purposes is that it agrees with materialism (or physicalism) about physics being causally complete. What happens in the world is just what comes about, given the initial and boundary conditions that prevail, as the result of bits of matter moving and interacting according to the basic laws of physics. That is how all efficient causes bring about their effects, according to materialism, and spatiomaterialism expects to be able to explain why those causal connections hold. Naturalists who follow the empirical method must prefer that kind of ontology, if it is possible, because it is the simplest explanation of what happens in nature. The only question is whether it is possible.

Immaterialism. It is not possible, according to critics of materialism, because there are aspects of the natural world that require us to postulate immaterial substances in space. Though all naturalists deny the existence of anything outside space and time, all the kinds of phenomena mentioned in Naturalism: Problems as posing a problem for naturalism also pose a problem for materialism. That is, consciousness, goodness and holiness, the phenomena that lead, respectively, to the belief in Cartesian minds, Platonic Forms, and a transcendent God, can also be used to argue for the existence of substances whose natures are not described by the basic laws of physics. However, to postulate mental substances, teleological substances, or spiritual substances would be to give up materialism in favor of a more complex ontology, one with immaterial substances that coincide with space and endure through time, along with material substances.

Notice that, although space is not a material substance, it is not an immaterial substance in the sense relevant here. Space is not a material substance in the sense that it has an opposite essential nature to matter. (Whereas bits of matter are independent of one another, parts of space cannot exist without one another.) But here we are concerned with the causal completeness of physics, and by "immaterial substances," we mean only substances that coincide with space. What makes them immaterial is that they do not move and interact as described by the basic laws of physics.

Though space is not a material substance, it is not an immaterial substance in the relevant sense, because substantivalism about space does not itself deny the causal completeness of physics. On the contrary, it affords an ontological explanation of why the basic laws of physics are true and, thus, an explanation of the connection between cause and effect in efficient-cause explanations.

Ironically, however, as it will turn out, all that needs to be added to materialism in order to explain the problematic phenomena that lead to belief in immaterial substances is substantivalism about space. As we shall see, that is because it shows the ontological necessity of global regularities, as well as the local regularities described by the basic laws of physics. It order to see what spatiomaterialism must do, let us consider more carefully each of the reasons for believing in immaterial substances.

Mental substances. The first challenge to materialism comes from the existence of conscious beings like us. As explained in Naturalism: Consciousness, the basic phenomenon that leads to belief in the existence of mind is "consciousness," which will be understood here as the fact that it is like something to perceive the world and experiences of other kinds. The appearances involved in perception are something distinct from what exists in the natural world independently of us, and when we reflect on how we know about them, it seems that the appearances themselves are responsible for our being aware of them and for the judgments we make about them. That is what led Descartes to believe that minds are immaterial substances not located in space. Though we must, as naturalists, deny the existence of Cartesian minds, we must give an ontological explanation of the natural world that explains the phenomenon of consciousness.

To be conscious is to have qualia or phenomenal properties. Since they are properties of a radically different kind from the physical properties by which the essential nature of matter is defined, materialism seems to be incapable of explaining consciousness. There are several alternatives.

Eliminative materialism. What materialists can do is explain away the phenomenon. That is the position called "eliminative materialism." It assumes that everything that conscious subjects do in the world can be explained by the brain and other forms of efficient causation. That means that there is no way to show that someone else is conscious by how they behave or anything else that happens in the world. Thus, consciousness eludes the method of empirical science, since the only acceptable evidence for scientific explanations is what is known by perception. Eliminative materialism would "solve" the problem of consciousness by simply denying the existence of phenomenal properties. It holds that belief in them is the result of a confusion (see Dennett) or the lack of an adequate scientific explanation of the brain (see Churchland.) This position is not easily refuted, since the evidence for consciousness is strictly private, in the sense that it depends on first-person reflection.

The willingness to reduce conscious subjects to what materialism can explain is, however, the sort of attitude that has given reductionistic materialism such a bad name. Most naturalists (like Chalmers) doubt that eliminative materialists are taking consciousness seriously, for naturalists are themselves parts of the natural world and they can know that they are conscious by reflection, even if natural science cannot.

Emergentism. At the other extreme is emergentism. It is possible for naturalists to give up materialism and hold that what explains this phenomenon are mental substances that coincide with space along with material substances. Emergentism is different from the belief in Cartesian minds, because it takes the mental substances to be in space, and for spatiomaterialists, to be contained by space as a substance is to coincide with some part(s) of it. But emergentism agrees with the Cartesian view about mental substances making a difference to what happens in the world. It holds that mental substances are partly responsible, at least, for behavior that is ordinarily attributed to conscious mind, such as rational behavior. Such a view, however, denies materialism, for it denies the causal completeness of physics. It implies that there are substances in space and time that do not obey the laws of physics, thereby denying that physics can, in principle, explain everything that happens in nature.[1]

It may seem that emergentism is not a form of immaterialism, because what emergentists mean by "conscious mind" cannot be a substance by our definition. We are assuming that substances never come into existence nor go out of existence over time, but emergentists typically hold that conscious mind comes into existence at some point because of the complexity of physical causes, for example, at some stage in the evolution of the brain. However, these views are not incompatible, because the way in which conscious mind emerges can be explained by assuming that matter itself has a (temporally complex) nature that allows its nature to change from being the kind described by the laws of physics to being a kind that gives consciousness a causal role in the world. That is to hold that there are immaterial substances in space, for it implies that there are substances that do not obey the basic laws of physics. That may mean that there are no material substances, only immaterial substances that appear at times to be material. In any case, it is a naturalistic theory. But since bits of matter would have to follow more complex laws than those of physics, the existence of emergent minds would require a more complex ontology, and thus, naturalists have good reason to prefer a less disruptive explanation of consciousness, if it is possible.

Epiphenomenalism. Epiphenomenalism is a compromise between eliminative materialism and emergentism. It holds that all the causal roles of conscious mind are really the work of the brain and, thus, can ultimately be explained by matter alone. Thus, it cleaves to materialism and believes in the causal completeness of physics. But it also holds that processes involving physical properties of those kinds "give rise" to phenomenal properties. That is how it explains the phenomenon of consciousness. Since those phenomenal properties have no effects, in turn, on what happens in the world, it is called "epi-phenomenalism." That is, phenomenal properties are effects of physical properties without ever themselves being causes of anything. Such a view avoids postulating any immaterial substances, since the substances in space would always obey the laws of physical. But it would have to assume that material substances can have properties that are not mentioned by the basic laws of physics. Thus, it accepts what is called "property dualism," while cleaving to materialism (or physicalism). Matter must have phenomenal properties as well as physical properties.

Epiphenomenalism is, however, an unhappy compromise, because phenomenal properties are fundamentally different from the properties by which materialists define the essential natures of material substances. They are not entailed by anything that physics can discover about the world. Thus, it is possible to conceive of a physical world in which organisms with brains exactly like our own did not have phenomenal properties. That is, there may be zombies. Or to use Kripke’s famous metaphor, epiphenomenalism makes it seem as though, God, after creating the physical world, had to go back and tack phenomenal properties onto material substances in order to make beings like us conscious. Thus, even though epiphenomenalism allows naturalists to avoid immaterialism, there is still reason to believe that materialism is not the deepest truth about the nature of existence in the natural world, because consciousness is still something found in the world that does not seem to be constituted by material substances.

In order to be the best ontological explanation of the natural world, therefore, spatiomaterialism must explain consciousness. That is, it must explain the relationship between physical and phenomenal properties in a way that shows phenomenological properties to be ontologically necessary.

And it can. Indeed, that will be the first necessary truth derived from this ontological foundation. (See Properties.)

However, since this is only a promise at this point, we are taking out a second mortgage on the house of ontological philosophy in order to construct its foundation (that is, in addition to explaining why Einsteinian relativity is true), and only if we pay off both mortgages will we have a clear title to a new way of doing philosophy. But as it now stands, if we do pay them back, the empirical method will require us to accept spatiomaterialism as true, and we will not be able to deny the necessary truths that follow from it. This argument will be a new way of doing philosophy.

Teleological substances. Another problem with naturalism is the existence of a real difference between good and bad, that is, a difference in the objects or events themselves that make it true that some ought to exist and others ought not. That is the phenomenon that led Plato to believe in the existence of Forms in a realm of Being, and the same phenomenon that theists believed they could explain by the existence of a God who created the natural world. Though as naturalists, we must deny both of those supernaturalistic explanations, we do need an explanation of the phenomenon itself. If it cannot be explained by materialism, goodness will count as evidence for the existence of immaterial substances.

Hedonism. The time-honored way for materialists to explain the phenomenon of goodness is by offering a causal explanation of what is good, such as psychological hedonism, that is, the view that beings like us cannot help but seek pleasure. But that is to hold, in effect, that pleasure is what is good without explaining why the good is good in the sense that it ought to exist. It would only explain why hedonistic beings like us inevitably pursue it.

Furthermore, hedonism does not explain moral goodness, for it does not explain why we ought to do what morality requires when it does not maximize our expected pleasure, that is, when it is not in our self-interest.

Nor is the goodness of morality explained by theories, like Hume's, that take human nature to include a moral sentiment, which inclines one to do what is moral when it conflicts with self interest. Such a psychological disposition may explain why human beings are moral, but not why they ought to be.

Non-cognitivism. The other traditional naturalistic attempt to explain the phenomenon of goodness is to hold that it is an illusion. The appearance that there is an objective difference between good and bad could comes from projecting our feelings about things onto the world, so that they appear to be properties of the objects themselves. This view has had many defenders in the Twentieth Century (such as Ayer).

These ways of answering the challenge of goodness are, once again, what has given materialist reductionism a bad name. They do not convince everyone, and those who continue to believe in a real difference between good and bad, in which the good really ought to exist regardless what we may happen to (or be determined to) believe about it, will accuse materialists of leaving something out of their supposedly complete explanation of the world. Thus, although materialism is the simplest ontological explanation of the natural world, the empirical method cannot force us to accept it as true as long it cannot explain goodness as something that beings like us find in the natural world.

In order to explain the phenomenon of goodness, it may be argued that naturalists must postulate teleological substances of some kind, such as Aristotle did by holding that there are final causes as well as efficient causes at work in nature. To suppose that forces of any kind are responsible for the goals pursued by biological organisms generally or by human beings would be to hold that there are substances that somehow guide change in nature to bring about certain states or goals. They could not be material substances, because substances whose essential natures are described by the basic laws of physics do not have such forward-looking effects (unless, of course, they have very special initial and boundary conditions as parts of mechanisms, which would need to be explained). In order to account for final causation, for example, Aristotle postulated essential forms as a component of each particular substance in space. Indeed, the actualization of the essential form that exists potentially in substances of its natural kind was supposed to be the end for the sake of which "natural change" takes place.

Nor was it just their role in final causation that made them immaterial substances. Though essential forms are located in space and time as a component, along with matter, of the particular substances that have them, the same essential form must be able to exist simultaneously in different particular substances with different locations in space at the same time. Thus, they are universals, not concrete material substances.

It may be possible to materialize teleological causation (as " vitalists" like Hans Driesch did) by postulating "entelechies" (instead of essential forms and final causes) and holding that each entelechy can exist at only one location in space at a time. But still, any substances exerting teleological forces would be unlike the substances that materialists accept, because in order to guide motion and interaction toward certain goals, they would have to work in more complex ways than provided by the basic laws of physics. And even if they did, making what is good objective, it would still be necessary to show how that explains why the goals pursued are good.

The defense of teleological substances has been rare ever since the discovery earlier in this century that Darwin was on the right track in explaining natural teleology as a result of evolution. Darwin showed how the natural selection of random variations in reproducing organisms could explain why change seems to occur for the sake of ends in them. The existence of traits serving specific functions was a result of the differential survival and reproduction of organisms having the traits, while other organisms, lacking the traits, died out. In other words, it is merely an adaptation to the environment. And when the role of genes in the inheritance of traits became clear, it was even harder to believe that immaterial substances were responsible for the goal-directed traits of biological organisms -- and harder still when DNA molecules were found to be playing the role of genes. Since nothing but efficient causes are involved in the mechanism of inheritance and their evolution by natural selection, it was no longer plausible to believe in the existence of teleological substances.

This evolutionary explanation of the goal-directedness of biological traits is not, however, an explanation of the phenomenon of goodness. The consensus among contemporary Darwinists is that Darwin’s theory has nothing to do with progressive evolution. As we mentioned earlier, they believe that the cause of natural selection is externally caused changes in the environment, which makes the course of evolution seem accidental. What is more, since organisms must make do with whatever random variations turn up when the environment changes, it also suggests that evolved traits are not generally the best way to serve the functions required, but merely what enabled them to survive difficult periods. (For a fuller discussion of contemporary Darwinism, see Change: Accidentalism.) Thus, to those who believe that there is a real difference between good and bad, one that explains why the good ought to exist, the contemporary Darwinist explanation of the ends pursued by organisms seems more like an attempt to debunk their belief in goodness than an explanation of its nature.

Goodness remains, therefore, a source of doubt about materialism. Though materialism may be part of the simplest explanation of the natural world, there will be naturalists who do not accept it, as long as it cannot explain why things are good in the sense that they ought to exist. They have reason to believe that teleological substances of some kind are required to explain this phenomena. The tradeoff between simplicity and scope prevents the empirical method from deciding.

In order to hold that the empirical method requires naturalists to believe that materialism is true, therefore, and that there are no immaterial substances in space, it will be necessary to explain the phenomenon of goodness to the satisfaction of those who believe in an objective difference between good and bad. That is, it will be necessary to give an explanation of the goals pursued by beings like us (and by other organisms) that explains why those goals ought to be pursued.

In order to establish this foundation for ontological philosophy, therefore, we must take out a third mortgage on the necessary truths supported by it. Not only must spatiomaterialism explain the truth of Einstein's two relativity theories and the nature of consciousness, but it must also explain the nature of goodness. And if it turns out that we cannot pay off these mortgages, it will not be clear that spatiomaterialism is the best ontological explanation of the natural world. We will not be entitled to claim that any truths founded on its are necessary relative to what is ordinarily believed.

It will, however, turn out that spatiomaterialism can pay off this mortgage. There is a better explanation of the difference between good and bad than contemporary Darwinists offer, and ironically, what makes it possible is the recognition that space is a substance. The key, once again, is how substantivalism about space entails the ontological necessity of global regularities, for evolution is the "Reproductive Global Regularity."

Spiritual substances. The final reason for doubting that materialism (or we are assuming, spatiomaterialism) is the best ontological explanation of the natural world is what we called the phenomenon of "holiness," which leads people to believe in the existence of a transcendent God. Though, as naturalists, we must deny the existence of a transcendent God, the phenomenon that gives rise to belief in God calls for explanation, and if we cannot explain why people believe that is something worthy of worship without postulating spiritual or other immaterial substances in space, the empirical method will not force naturalists to accept spatiomaterialism. There will again be a tradeoff between simplicity and greater scope that makes it unclear whether spatiomaterialism or some from of immaterialism is the better ontological of the natural world.

In this case, once again, a common materialist response to the challenge is to hold that what needs explaining is not the phenomenon of holiness, but rather the belief in God itself. Thus, people are said to have a psychological need to believe in God, either as a result of conditioning (behaviorism), psycho-sexual development (Freudianism), an instinct selected for other functions (sociobiology), or some other irrational cause. This is materialist reductionism in the pejorative sense. It does not take seriously the source of the belief in the sacred, at least, not in the eyes of those who believe there is something worthy of worship.

This sort of explanation is not required by naturalism, that is, the denial of supernaturalism, for religious people can be naturalists. Though naturalists cannot believe in the existence of a transcendent God of any kind, they can insist that there is something immaterial in the natural world that is worthy of worship. It is not obvious, after all, that what is holy must exist outside space and time. It could be a spiritual substance in space, if not the world itself.

The existence of spiritual substances is not, however, compatible with materialism. A spiritual substance must have effects that are different from what happens as bits of matter move and interact according to the basic laws of physics, for otherwise there would be no reason to believe that a spiritual substance exists, much less that it is worthy of worship. Thus, it must not be a material substance in our sense.

Nor is it sufficient to declare that the world itself is worthy of worship. There must be something about the world that makes it holy, and naturalists have never explained what it is.

Spinoza's pantheism was rejected by traditional theists for this reason. His metaphysics explained why goals are pursued by beings in the world, but it denied that pursuing them was a result of free will and it failed to explain why those goals are good.

It may not seem necessary, in the case of holiness, to take out a fourth mortgage to establish spatiomaterialism as the foundation for a new way of doing philosophy, because if spatiomaterialism can explain everything but how there is something worthy of worship in the natural world, it could be argued that what we have discovered is that there is nothing sacred in space.

However, that would not work, if there were naturalists who continued to believe in the sacred, because they would insist that it can be explained by some kind of immaterialism. And if they were not just being willful or arbitrary, but argued with us, giving reasons for believing in spiritual substances of some kind, we could not claim that the empirical method forces naturalists to believe that spatiomaterialism is true. There would be a tradeoff between the simplicity of materialism and the scope of immaterialism, and we could not, in good conscience, defend any of the necessary truths of ontological philosophy.

Thus, we will take out a fourth mortgage on the foundation needed to do philosophy in this new way. It may seem wildly optimistic at this point, or even foolish, to promise an explanation of holiness. But as we shall see, spatiomaterialism does show that there is something in or about the natural world that is worthy of worship. This fourth mortgage will be paid back in the sense that either the religiously inclined will agree that it explains what they are getting at, or else we will have sufficient grounds for holding that they are not being fully rational about all the relevant issues in rejecting it. The dispute may continue at that point, but it will be about their rationality, not about whether spatiomaterialism is the foundation for a new way of doing philosophy.

 

This completes the construction of the foundation of ontological philosophy, though we carry quite a burden with us as we take up the project of using spatiomaterialism as a foundation for necessary truths. In order to hold that spatiomaterialism is the best ontological explanation of the natural world, we must explain why Einsteinian relativity is true, why beings like us are conscious, how there is a real difference between good and bad, and how there is something in the natural world that is worthy of worship. If we can pay off those mortgages, however, the edifice that we shall construct on that foundation will stand. What spatiomaterialism implies about the world will hold necessarily relative to science and our ordinary ways of reasoning about what to believe, including empirical science, ethics, and the whole gamut of ordinary cognitive endeavors. And the use of an empirical naturalistic ontology as a foundation for necessary truths will have proved itself to be a new way of doing philosophy.