Epistemological philosophy of causation. This ontological explanation of change has implications about the nature of efficient causation that solves various problems that have arisen in epistemological philosophy of science, and following them out here may help clarify the significance of ontological philosophy.

More central issues in epistemological philosophy of science, about realism, which arise from its attempt to show the validity of natural science, have already been discussed in describing contemporary philosophy, the last era in the history of epistemological philosophy.  We have seen in discussing the philosophical spiritual stage how ontological philosophy would join the issue about scientific realism and metaphysical realism and defend the truth of the conclusions of the empirical method of natural science.

The problems about causation in epistemological philosophy of science fall into two main categories. One arises in natural science about the nature of efficient causation, and the other arises in social science about the nature of rational causation (and, thus, about the basic nature of human society as such).

The difference between natural and social science arises, as we have seen (in Stage 9), from the difference between naturalistic and subjectivistic understanding. It illustrates one of the dichotomies of rational culture that epistemological philosophy has not adequately overcome, and though we already know how it is over come, it may be useful to see how it works out in the context of current discussions in philosophy of science.

Efficient causation. Efficient-cause explanations show that the events and conditions identified as causes produce the events and conditions identified as their consequences.

Efficient causes are different from ontological causes, because efficient causes precede their effects in time (though when both are static conditions, the temporal priority may not be obvious). Ontological causes are simultaneous with their effect, because they produce their effect by constituting them. That is, the existence of ontological effects is part of what already exists in the ontological causes.

Ontological cause explanations are, therefore, self contained and do not call for any deeper explanation. Ontological causes are substances, which are self-subsistent, and the connection between them and their effects is a kind of identity. Ontological effects are identical to parts or aspects of their ontological causes. Seeing the connection between ontological cause and effect is, therefore, just a matter of recognizing that the substances involved have a certain aspect, and as we have seen, the power of rational beings to single out aspects of the natural world is explained by the nature of rational imagination. (Rational imagination includes spatial and structural imagination as well as naturalistic and reflective imagination -- that is, imagination that depends on natural and psychological sentences, respectively).

Efficient-cause explanations, on the other hand, require further support, because the efficient causes and their effects are distinct events or states (or even less general regularities, in the case of reductive efficient-cause explanations). The connections cited in empirical science are laws of nature, which are descriptions of regularities about change that are observed in nature. Though epistemological philosophy of science does not recognize anything more basic than laws of nature, it has recognized, ever since Hume, that something more seems to be required. Efficient-cause explanations call for a deeper explanation.

By efficient-cause explanations, I mean explanations that conform to the "covering law model" of explanation. As represented in the so-called deductive-nomological model, each such explanation is a deductive argument in which the conclusion describes what is explained (a particular event or condition or else a regularity that holds under certain conditions). The premises are of two kinds, laws of nature and descriptions of relevant initial and/or boundary conditions. The explanation depends on deducing a description of what is being explained from the premises, that is, showing them to be instances of the relevant laws of nature.

Something about the nature of efficient causes can be inferred from the standard for judging the best explanation, which is part of the empirical method itself. As we saw in Method, that standard is explaining the most with the least. Applying it to the case of efficient-cause explanations, the best explanations of any given phenomenon is the one that uses the fewest and simplest laws of nature, for that means it uses the fewest and simplest causes. But science aspires to explain all natural phenomena, and thus, more generally, the best explanation is not merely the simplest, but also the one with the largest scope. (There can be tradeoffs between simplicity and scope that make it difficult to tell which explanation is best, though in practice, such conflicts tend to be resolved by further discoveries.) In general, therefore, the goal of science is to discover the fewest, simplest and most general laws of nature that are able to explain all the particular events and conditions (and less general laws) by their efficient causes.

The covering law model is not a very satisfactory explanation of the nature of efficient causes, because it comes down to the nature of laws of nature, and that is no less problematic than the nature of efficient causes. The problem is not solved by discovering the most basic laws of nature (the basic laws of ideal physics), because even at the bottom, there is no explanation of why there is a connection between efficient causes and their effect. There is only the description of a regularity.

In less general branches of natural science, there is nevertheless hope of explaining how efficient causes produce their effects, for it seems possible to reduce them to explanations in more basic branches of science and ultimately to the laws of physics. But this expectation is not satisfied for two reasons. First, the laws and explanations given in physics do not reveal the nature of the casual connection in the most basic efficient causes. And second, many of the laws and explanations of less general branches of science cannot be reduced to those of physics.

As we shall see, the second problem comes down to the first, because the irreducibility of the laws, properties and efficient causes cited in the less general branches of science to physics is a result of the lack of any deeper explanation of the truth of the basic laws of physics.

But first, let us consider the basic laws and explanations of empirical physics and how they are explained ontologically. That will enable us to see how the apparently irreducible laws, properties and efficient-cause explanations of less general branches of natural science can be reduced to ontology, albeit not to the laws of physics.

Basic laws. The most basic laws of nature are the basic laws of physics. They describe relationships between basic quantitative properties that require mathematics to be stated exactly and completely, and what they predict are usually precise measurements that are otherwise unpredictable. Considering their vulnerability to refutation by observation, the success of physics in discovering such laws make it undeniable that physics is on to something real about the world. And the search for the holy grail in physics has been for many decades now the attempt to find a single, most basic law that would include all four of the basic forces of nature (not only electromagnetism, the strong force, and the weak force, but also gravitation).

But as we have seen, its conception of the holy grail shows the limitation of the empirical method of physics. Physics infers to the best efficient-cause explanation of what is observed in nature and uses that to determine its ontology instead of inferring to the best ontological-cause (and best efficient-cause) explanation. It discovers basic laws and affirms the existence of what those laws must refer to, instead of trying at the same time to explain the basic features of the natural world (why bits of matter have spatial relations and how change is possible). But even if there were a single law from which all the other could be derived — and we have seen why that is not possible in our ontological explanation of the truth of Einstein’s general theory of relativity — it would not reveal the nature of the efficient causes.

Ever since Hume, it has been recognized that even though physical laws describe causal connections, there is a problem about what such laws correspond to. As Hume argued, the most that science can know about the causal connections described by its laws of nature is just that certain regularities hold in nature. That does not reveal the nature of the power or necessity by which causes produce their effects. Hume recognized that the problem about causation is not solved by explaining regularities about observable processes by appealing to physical laws describing how their more elementary parts behave, because that merely shifts the problem to the basic laws of physics. Hume was a skeptic who took this difficulty to its extreme, arguing that since all we really know is that certain regularities have so far been observed to hold in nature, we are not even rationally entitled to predict that the same will be true in the future.

Skepticism is not, however, what leads us to expect that, if science were to know the truth about efficient causes, it would be able to explain how efficient causes produce their effects. It is rather that, since laws are just descriptions of regularities, there must be something that makes the regularities true. That is what is offered by an ontological explanation of the basic laws of physics. Even the ontology of generic spatiomaterialism is able to explain some aspects of the regularities described by laws of physics and show them to be ontologically necessary. Consider how the ontologically necessary principle of local motion contradicts Hume’s view that we can never know the necessity of any regularity, but only the constant conjunction itself.^[1]

When one billiard ball hits another, it causes the second ball to start moving. Apart from such events being constantly conjoined in experience, he argued, we could not know anything about what would happen. To an extent, Hume is correct, for experience does tell us that the first ball will not just stop when it reaches the second ball, that it will not bounce back nor go around the second ball and proceed on its way. But Hume is wrong to hold that we can have no knowledge of what is necessary. For if we are spatiomaterialists, we know that the first billiard ball cannot simply disappear from the front side of the second billiard ball at one moment and then simply reappear on the other side at the next moment. The principle of motion does not tell us precisely what will happen, but it does limit the possibilities. But neither does it depend merely on the experience of that constant conjunction. Its necessity depends on our reasons for believing that spatiomaterialism is the best way of explaining the natural world by substances existing in time. Inferring to a deeper kind of explanation of nature than science gives us a foundation for showing the necessity of at least certain aspects of the constant conjunctions that science discovers by inferring to the best efficient-cause explanations.

The principle of local action is also ontologically necessary, and it can also tell us something about the billiard ball that is prior to the experiences of what happens to them that Hume is talking about. Experience of constant conjunctions of events in the past may be the only way of predicting precisely what will happen, but we do know prior to experience that the first ball will not change the motion of the second ball without either contacting it or exerting a force or modifying space in a way that reaches out across space as time passes to affect it. Thus, spatiomaterialism shows that another aspect of the regularities that science knows only from experience of constant conjunctions is ontologically necessary.

What these examples are pointing to, however, is a deeper, ontological explanation of all the aspects of the regularities described by the basic laws of physics. The ontological explanation of the connection between efficient cause and effect comes from showing how the causes and effects are constituted by substances enduring through time. Efficient causes and effects are just aspects of those substances (that is, states of affairs or events constituted by them), and since the natures of the substances and how they exist together as a world constrains what can happen to them, there are certain ontologically necessary truths about how change can and cannot take place. Thus, when space and matter are assumed to have more detailed essential  natures, further aspects of the regularities about change are also explained ontologically. That is how the truth of the basic laws of physics were explained ontologically in discussing contingent laws (Local regularities).

Such an ontological explanation of the truth of the basic laws of physics does not, of course, show that they are among the necessary truths proved by ontological philosophy. They do not follow from spatiomaterialism by itself. Instead, the theories about the nature of space and matter that were proposed are, rather, inferences to the best ontological explanation of the basic laws of physics, given the truth of spatiomaterialism. Their role in this argument was to show that it is possible, despite appearances to the contrary from contemporary physics, that the natural world is constituted by space and matter enduring though time as substances.

But even though the basic laws of physics are not ontologically necessary truths, the ontological explanation of why they are true within the constraints of spatiomaterialism is an ontological explanation of the connection between the efficient causes and their effect mentioned in the explanations of physics. It explains the "necessity" of the connection between cause and effect, or the "power" by which the efficient cause produces its effect.

There is, therefore, a way of explaining ontologically the connections between efficient causes and their effects, and as we shall see, the reason that regularities discovered by the less general branches of science are not reducible to physics is its failure to take the role of space as an ontological cause into account.

Irreducible regularities. Even when it was assumed that there is no solution to the problem about the nature of efficient causation in physics, it seemed that efficient-cause connections in less general branches of natural science could be solved by reducing their efficient-cause explanations to efficient-cause explanations in physics. Though that would not solve the basic problem, it would locate all the problems in physics, and the other branches of science could hope to explain the regularities they discovered by those discovered by physics.

On the deductive-nomological model of explanation, such reductive explanations would involve deducing the laws of less general branches of natural science from the basic laws of physics together with relevant initial and boundary conditions. Regularities would be explained in the same way as events or states of affairs, because they would be shown to depend on certain deeper initial and boundary conditions as their efficient causes. This was a project proposed by logical positivists to show what they called “the unity of science.”

Attempts have been made to reduce the theories discovered by less general branches of science, from chemistry and biology to physiology and psychology, to physics. But this project encountered various obstacles. They all involve the discovery of what seem to be irreducible laws of nature.

To be sure, it is often assumed that properties, such as functional properties, can be irreducible in the sense of being supervenient without holding that there are any irreducible laws. But as we shall see, supervenient properties presuppose irreducible laws. It is just that those laws are not the kind that support efficient cause explanations. The regularities they describe have to do with constant conjunctions that are explicitly assumed not to be causal. But they are nonetheless irreducible in the sense of not being explainable by physics, except as accidents.

We will consider the obstacles to reductionism in natural science in three classes, those having to do with thermodynamics, those having to do with mechanical principles, and those having to do with evolution. These problems correspond to three kinds of global regularities, material, structural and reproductive, respectively. Thus, it should not be surprising that what makes it possible to overcome the irreducibility to physics is the recognition of the role that the wholeness of space plays as an ontological cause, for that is what made it possible to explain the global regularities ontologically.

This does not, of course, show that these less general laws of nature are reducible to physics. They still cannot be deduced from the laws of physics and initial and boundary conditions, at least, not in a way that anyone takes to explain the regularity. But it does show that they are ontologically reducible in a spatiomaterial world like ours. That is, they could be explained by   an “ontological natural science,” or a natural science in which empirical ontology was recognized to be a more basic branch of natural science than physics, because physics would then formulate its efficient-cause explanations on the assumption that space is a substance enduring through time. In other words, the solution to the puzzles posed by the apparent irreducibility of less general laws of nature does not depend on any of the theories about the more specific natures of space and matter required to explain the truth of the basic laws of physics. What is crucial is only the recognition that space is a substance, because when it is seen as one of the substances constituting the regularity, its nature can be seen as constraining what happens in the world, that is, as an ontological cause. What seems to be irreducible regularities are, in fact, ontological effects, specifically, global regularities.

The advantage of this ontological reduction of physically irreducible regularities is that it takes the steam out of the engine that is currently pulling epistemological philosophy of science toward the acceptance of emergentism, or laws that deny that physics offer a complete efficient-cause explanation of what happens in the world. It shows that the irreducibility of laws to physics is not a reason to suppose that there are other kinds of efficient causes at work in nature. What I mean by this tendency are illustrated by the following examples.

Self-organizing systems. There are thermodynamicists, such as Prigogine (1980), who see the phenomena described by the second law of thermodynamics as evidence of "self-organizing" systems. The systems that are supposed to organize themselves are made of matter, but if matter is doing anything more than obeying the laws of motion and the laws about the attractive and repulsive forces that are recognized by physics, it is hard to avoid the suggestion that it is a holistic kind of matter exerting an emergent force of order in some way.^[2]

Stratification of nature. Emergentism is more explicit in the belief that nature itself is "stratified" according to branches of science, so that the laws discovered in chemistry, biology, physiology, psychology, and social science are each as basic as any discovered by physics.^[3] This would mean that every branch of science discovers not only properties, but also laws of nature, that are emergent with respect physics, because to accept the stratification of nature is to assume that there is something sui generis about the laws of each higher branch of science that makes them irreducible to lower level laws (and relevant initial and boundary conditions), or at least not reducible to laws of physics and physical conditions.

Emergent evolutionism. The defense of emergentism has a long history.^[4] A view called "emergent evolutionism" was defended, for example, by philosophers like C. Lloyd Morgan (1920) and Samuel Alexander (1920). They postulated a kind of matter whose essential nature included emergent powers that were supposed to account for the order that exists in nature, including the "new forms of relatedness" that show up in the course of evolution over time at several levels of complexity. Their emergentism is not all that different from "process philosophy," which began with Alfred North Whitehead (1927, 1929) and has been taken up by Charles Hartshorn (1970), Errol Harris (1965), and others. Although they deny that nature is stratified, they assume that what accounts for the apparent truth of the laws of physics as well as the order in nature is a subjective nature that is found in even the simplest particulars.

Chaos theory. Emergentism seems to be what is being suggested by defenders of the recently popular "chaos theory." They point to the way in which random motion and interaction sometimes seems to break out into order to suggest that there is some heretofore unrecognized emergent aspect of matter.^[5] But instead of defending emergentism explicitly, they are content to present these phenomena in the vein of a mystery yet to be solved.