Change is the third and largest category of necessary truths that follow from spatiomaterialism. It covers all the phenomena that empirical science would explain by laws of nature and efficient causes. But ontological philosophy explains the regularities described by those laws as an aspect that the substances constituting the world, namely, the aspect they have because they endure through time constituting different properties and relations at different moments.

Change can be explained ontologically because the existential aspect of the nature of substance as substance includes a temporal aspect: substances endure through time. But the change that is explained ontologically is an aspect of the world, rather than substances taken separately, because ontology explains the way that properties and relations come into existence and go out of existence by how they are constituted jointly by different substances that endure through time. That is, change is not merely an assumption of ontology.

Local regularities about change are regularities about how bits of matter move and interact relative to certain other bits of matter (whereas global regularities have to do with how the locations, motion and interactions of all the bits of matter in a region add up as time passes). But there is a difference between ontologically necessary principles about local regularities and contingent laws about them.

Necessary principles describe aspects of local regularities that are entailed by spatiomaterialism. The possibility of change was explained ontologically by showing how it could be constituted by space and matter enduring through time and by how all the bits of matter coincide with some part of space or other. Those same ontological causes are also responsible for certain limits about how change can take place.

The principle of local motion holds that bits of matter can change location only by moving continuously across space as time passes. A bit of matter that flitted about discontinuously from place to place as time passes would contradict at least one of the assumptions of spatiomaterialism.

The principle of local action holds that bits of matter can interact with one another only when they occupy the same or adjacent locations in space at the same time or something travels across space between them (either a bit of matter or a change in space itself). This limit follows from space being the substance that connects the bits of matter. Even changes in space can propagate only at a finite velocity, because the parts of space are distinct substances, despite their essential geometrical relations, and each can affect only its neighbors as they all endure through time.

Contingent laws describe more detailed regularities about how bits of matter move and interact than the limits imposed by necessary principles about local regularities. The truth of the basic laws of physics depend on space and matter having more specific natures than required by spatiomaterialism. But to show how those laws can be descriptions of aspects of a spatiomaterial world is to explain them ontologically. That is not surprising in the case of classical physics, but it is precisely what contemporary physics seems to deny.

Classical physics is roughly physics as it was about the end of the 19th Century. Newton's laws and Maxwell's laws can be explained by assuming that space and matter have certain specific natures. One way of doing so is presented, though a better way may be found. But the way offered shows that it is possible and what an such an ontological explanation is. It is introduced by way of a catalogue the four kinds (or forms) of matter that will be involved.

The four forms of matter explain the truth of the principle of the conservation of mass and energy. Besides material objects with rest mass, there is kinetic matter (which explains the motion of material objects), and two kinds of matter are needed to explain the two basic forces, gravitation and electromagnetism (though in each case there is a difference between its potential and actual forms).

These four forms of matter have natures that can explain ontologically why Newton's three laws of motion and law of gravitation are true. Though its possibility is not surprising, the explanations are not trivial and they lay the foundation for a deeper explanation that comes with explaining the truth of contemporary physics. The recognition of kinetic matter entails Newton's first law. The explanation of the second and third laws begins an ontological explanation of the difference between momentum and kinetic energy, and the explanation of Newton's law of gravity begins the ontological explanation of Einstein's theory of relativity.

Maxwell's laws describe the electromagnetic force. The electric force is explained in the same way as the gravitational force, namely, as a kind of matter that is spread out in space around the object exerting it where it can affect the motion of other objects. It is potential energy that can take an actual form, but the electric force is more complex because of its interaction with the magnetic force. This ontological explanation takes space to play the role of the luminiferous ether, implying that light has a determinate velocity relative to space.

Contemporary physics includes Einstein's two relativity theories and quantum mechanics. We must explain the regularities described by those relativity theories as aspects of a spatiomaterial world, for that is the second mortgage we took out in order to use spatiomaterialism as the foundation for ontological philosophy. Similar doubts based on quantum mechanics are answered by showing that there is one way, at least, that the truth of its laws can be explained as aspects of space and matter as substances in time. That provides the foundation for speculation about the basic particles and issues in cosmology.

The regularities described by Einstein's special theory of relativity can be explained as aspects of space and matter enduring as substances through time on the assumption that space interacts with high velocity material objects by imposing three distortions on them (shrinking their lengths, slowing down their processes, and increasing their mass), because those "Lorentz distortions" work together with the mis-synchronization of clocks according to Einstein's definition of simultaneity to make it appear that all inertial frames are observationally equivalent.

The regularities described by Einstein's general theory of relativity can be explained as aspects of space and matter enduring as substances through time on the assumption that centers of matter act on space in a way that changes the velocity of light relative to space as if there were an ether in space being accelerated by such centers of matter. Though the force accelerating the ether declines with the square of the distance, it propagates only at the velocity of light, and processes on material object that resist the acceleration of the ether are slowed down.

The regularities described by quantum mechanics can also be explained as aspects of space and matter enduring through time as substances. There may be other ways of doing so, but one is the quantum theory of matter and how it coincides with space, showing that it is possible. Since these phenomena occur within the ether that explains gravitation, only three kinds of matter are involved, and the nature of each is explained by cycles of quantum events (or potential quantum events). Quantum matter explains all the puzzling quantum phenomena. It also explains the quantitative relationship between momentum and kinetic energy.

The ontological explanation of the truth of theories in contemporary physics not only solves the problem about how quantum and gravitational phenomena are related, but also opens up the possibility of a new kind of explanation of the basic particles and a radically different approach to the explanation of cosmological processes, though these hypotheses remain speculative.

Global regularities are regularities about how properties of whole regions of space change as a result of how the locations, motions and interactions of all the bits of matter add up in the region as time passes. By making them add up, the wholeness of space is the ontological cause of global regularities, just as the structure of space causes local regularities by determining how motion and interaction changes spatial relations. But (most) global regularities depend on space and matter having a nature that makes the basic laws of physics true, and thus, their truth is only conditionally necessary. They must hold in any spatiomaterial world like ours.

The spatial global regularity is the principle of the conservation of matter, which holds that the total quantity of matter in any closed or isolated region of space does not change. It cannot change, because any change would involve a violation of the principles of local motion or local action. It is due to spatial causation because it depends only on space and how bits of matter have locations by coinciding with parts of space. Since matter is either mass or energy, this entails the principle of the conservation of mass and energy, and thus, it explains the principle of the conservation of energy, the first law of thermodynamics, given that there is no transformation of matter between rest mass and energy.

The material global regularities are an ontological explanation of the second law of thermodynamics, which holds that the entropy in any closed or isolated region of space cannot decrease. Two tendencies are involved. The wholeness of space causes both by requiring the motion and interaction of the bits of matter located in the region to add up as time passes. But how they add up in space depends on the specific nature that matter must have to explain why the basic laws of physics are true.

The first is the tendency of matter in the form of potential energy to become kinetic energy. This tendency holds because potential energy depends on certain geometrical structures about the bits of matter in the region of space, whereas when it becomes kinetic energy, it is a form of matter that coincides with the material object that is moving. As the matter moves away with the objects and is divided up by collisions, the special geometrical relationships required to restore matter as potential energy are unlikely to occur.

The other material global regularity is the tendency of kinetic energy to become evenly distributed heat. Because of how the motion and interaction of bits of matter add up in the region as time passes, three factors tend to become evenly distributed in the region of space. Material objects tend to have locations evenly spread out, kinetic energy tends to be distributed evenly among them, and directions of motion tend to be spread out evenly among them. Combined with the first tendency, there is a flow of matter from potential energy toward evenly distributed heat, and entropy is a measure of the proportion of the total energy in the region that exists as evenly distributed heat.

Structural global regularities are an explanation of the principles of mechanics, from dispositions to how machines use free energy to do work. Material objects with geometrical structures that do not change as they move and interact with other objects in space are the ontological cause that works together with space to make all the local changes in the region add up to a global regularity as time passes. Such material structures are byproducts of the tendency of potential energy to become kinetic energy and, thus, are derivative substances

Reversible processes are how the motion and interaction of bits of matter located in the region add up in space as time passes when they include material structures (but there is no thermodynamic flow of matter from potential energy toward evenly distributed heat). The only regularity is that the material structures do not change their geometrical structures as they move and interact. But these are genuine regularities about change in whole regions of space, as shown by such examples as the behavior of a box of gas or a link chain

Irreversible global regularities are generated when material structures coincide in certain ways with the thermodynamic flow of matter from potential energy to evenly distributed heat. As structural causes, they constrain the motion and interaction of the bits of matter involved in the thermodynamic flow so that what happens adds up over time to certain events that would otherwise be quite improbable That is how structural causes, or machines, use the free energy (inherent in the thermodynamic flow) to do work.

Reproductive global regularities are an explanation of evolutionary change. They are caused ontologically by space and reproductive cycles (as a kind of derivative substance). Reproductive cycles are complex material structures that use free energy to go through cycles in which they both reproduce themselves and control conditions that affect their reproduction. By reproducing, they impose natural selection on themselves, and thus, local change adds up in space over time to gradual change in the direction of greater power. And successively higher levels of part-whole complexity in the complex material structures going through reproductive cycles determine a series of stages of gradual evolution. (Click for detailed diagram.)

The explanation of change as an aspect of the substances constituting a spatiomaterial world like ours solves various problems about the nature of causation that have arisen in the epistemological philosophy of science. Problems in natural science have mainly to do with efficient causation, and problems in social science have to do with rational causation.

Efficient-cause explanations describe how events or states are produced by other events or states that occur earlier, and they appeal to laws of nature to show the connection between the efficient cause and it effects (according to the deductive nomological model). Thus, attempts to show the validity of such explanations must explain the nature of laws of nature.

Ontological philosophy solves the basic problem about efficient cause explanations. Though efficient causes are assumed to produce their effect, there is, as Hume argued,no way to show a necessary connection between them, because all that perception ever reveals about them are regularities, or constant conjunctions of events. But Hume was overlooking the possibility of empirical ontology, for a necessary connection between efficient causes and effects is shown when the change is explained as an aspect of substances that endure through time.

Epistemological philosophy of science attempts to explain the validity of efficient-cause explanations in less general branches of science by reducing them to laws of physics. But the attempt fails, because such reductions turn out to be impossible. However, the failures come from overlooking space as an ontological cause of global regularities, and laws that cannot be reduced to laws of physics can be reduced ontologically to spatiomaterialism

The second law of thermodynamics is said to be reduced to statistical mechanics, but the reduction is not complete, as Loschmidt pointed out, because statistics and physical laws do not explain the temporal direction of the change described by the law, that is, why entropy can only increase as time passes. But the temporal asymmetry is explained, when of the second law is explained ontologically. The wholeness of space shows how a geometrical aspect about the motion and interaction of material objects causes randomness to increase, rather than decrease as time passes.

The problem encountered in attempts to explain less general dispositions by the basic laws of physics is that the regularity involves indefinitely many different kinds of efficient cause connections on the physical level. Three examples are considered, and in each case, the disposition does turn out to be ontologically reducible when the role of space as an ontological cause of structural global regularities is taken into account. .

Functional properties also seem to be irreducible because they "supervene" on physical properties. There seem to be indefinitely many different kinds of traits that serve the same functions, and thus, no general connection between functional and physical properties by which they could be reduced to physics. But functional properties can be explained when evolution is explained as a global regularity constituted by space and reproductive cycles, because functions explain the evolution of the traits that serve them in a way that makes it possible, in principle, to predict their physical traits.

The problems about causation that arise in psychology and the social science have to do with the nature of rational cause explanation. They are solved by explaining evolution as a global regularity, because reason has an essential nature that is determined by its evolution at a certain stage. Reasons are causes of behavior that are represented as causes of behavior as an essential part of the process of causing behavior, and thus, the capacity to understand such explanations (subjectivistic understanding) is part of reason.

Psychology is the science that attempt to explain individual behavior, and there is a basic dispute between a hermeneutic approach, which denies that rational explanations are reducible to physics, and various forms of naturalism (behaviorism, functionalism and neurophysiology), which dispute about whether it can be reduced to physics. Ontological philosophy not only shows how rational explanations are reducible in a way that confirms their validity, but it also explains why this dispute arises.

The hermeneutical approach assumes that rational cause explanations are not reducible to efficient cause explanations, and it proposes to use them to explain individual behavior in social science. The ontological explanation of reason explains the apparent irreducibility of rational explanations to efficient cause explanations by the difference between subjectivistic and naturalistic understanding. It also explains the validity of rational explanations, though they do not always lead to agreement about what is true, like efficient-cause explanation

Naturalists would make psychology a natural science, though they disagree about whether its explanations are reducible to its efficient cause explanations. Behaviorism is now recognized as having failed in its attempt to find a general law of nature that explains all behavior by efficient causes. Ontological philosophy shows how neurophysiology can succeed in reducing rational explanations (and not merely replace them). Functionalists use the computer analogy to deny that psychological theories are physically reducible, but the ontological reduction shows how that analogy is misleading.

Epistemological philosophers disagree about the reducibility of laws in social science. Individualists argue that they are reducible to the rationally explained behavior of individuals, though they generally assume that such psychology is not further reducible. Holists insist that natural laws in social science are irreducible or even that there are irreducible entities mentioned by those laws. Ontological philosophy shows how both sides are true and how both sides are and false.

Methodological individualism holds that social phenomena, including social regularities, can be explained as the intended or unintended consequences of the rationally explicable behavior of all the individuals n the situations they face. (Sociobiology is a more radical individualism which would reduce social phenomena to genetically explained behavior of individuals.) Ontological philosophy reveals four different ways in which methodological individualism overlooks (or slights) the effect of spiritual animals on their members.

Though there are natural laws of social phenomena that are not reducible to individual behavior, that does not mean that they are not ontologically reducible. They can all be explained when the role of space is taken into account and various reproductive global regularities are recognized. But ontological philosophy must reject forms of social holism that affirm the existence of social level entities that are not constituted by space and matter (such as Hegel's "objective spirit").