Abstract and Keywords
The Introduction includes a discussion of the nature of metaphysical inquiry and an overview of the chapters that follow. Substances are simple, lacking parts that are themselves substances. Properties are modes, not universals, particular ways particular substances are. Arrangements of interrelated propertied substances serve as truthmakers for truths that have truthmakers. Relational truths are indispensable, but it could turn out that truthmakers for such truths are nonrelational features of the universe. Ontology cannot be ‘read off’ sentences used to express truths about the universe. The deep story about the nature of these truthmakers is the subject matter of fundamental physics.
When the objects of an inquiry, in any department, have principles, conditions, or elements, it is through acquaintance with these that knowledge…is attained.…The natural way of doing this is to start with the things that are more knowable and obvious to us and proceed toward those that are more knowable and clearer by nature; for the same things are not ‘knowable relative to us’ and ‘knowable’ without qualification. In the present inquiry we must follow this method and advance from what is more obscure by nature, but clearer to us, towards what is more clear and more knowable by nature.
(Aristotle, Physics 184a 1–20)
1.1 Ground Rules
In the pages that follow, I advance an ontological picture of the universe as we find it, a picture meant to be realist (the universe is as it is independently of our thoughts about it), particularist (existing things are particular; generality is a feature of our ways of representing the universe), naturalistic (the universe is all there is), and from the gut (it stems, not from a nuanced analysis of talk about the universe, but from repeated head-on confrontations with the universe). Minds and their contents, no less than billiard balls, trees, and planets, are what result from arrangements of the fundamental things. The mental–physical distinction is one of conception only, not what would traditionally have been called a real distinction. This is not dualism, not physicalism, not materialism; but it is not reductionism either. If the mental–physical distinction is not ontologically deep, there is no question of reducing the one to the other.
A picture of this kind has its roots in age-old reflections on the nature of being, the nature of what there is. What there is, however, (p.2) is not something that could be ascertained by looking at what we ‘quantify over’ in our best confirmed theories. It is one thing to know what theories you accept, to know what you take to be true, quite another matter to know what the world is or must be like if those theories are true. This is so for philosophy no less than it is for the sciences. In both cases, the aim is to discover, not just the truths, but the nature of the truthmakers for these truths.
This is the soul of realism. You can have good reason to accept a theory, yet that theory could turn out to be false. You can have good reason to accept a true theory, yet have no very clear understanding of what it is about the world that makes the theory true, the nature of the truthmakers. The universe disclosed by fundamental physics could turn out to be utterly surprising. The universe might be not at all as we currently take it to be. Whatever conception we develop, however, will be one encompassing substances and properties. The substances might be corpuscles, or electrons, or superstrings, or fields, or space–time itself, or something stranger still. Whatever the substance is or the substances are, it or they must be various ways: substances must have properties.
These assertions are meant to reflect not merely a limit on our thoughts about the universe, but a limit on the universe, a limit on how the universe, any universe, could be, hence a limit on scientific theorizing about the universe.
Think of fundamental physics as being in the business of telling us how the universe is. Fundamental ontology is in the business of telling us what the universe must be like if any theory is true. In this way ontology constrains science. Ontology does so, not by laying down immutable principles a priori, but by working in concert with science to discern the texture of being. One perhaps surprising consequence of this endeavour is the discovery of how often our predecessors were on target, even when they were wrong about the details.
1.2 The Province of Metaphysics
For millennia, philosophers engaged in metaphysical reflection without paying much heed to the nature of the enterprise. That changed with the advent of empiricism in the eighteenth century. Hume (p.3) argued that metaphysical theorizing divorced from empirical observation was empty, a projection of our own psychological makeup with no objective standing. Kant, taking Hume’s point, made a virtue of necessity. To the extent that metaphysics affords an accounting of the structure of our thoughts about the universe, it provides an indispensable service. The mistake, Kant thought, was to imagine that metaphysical theses might reveal the nature of an objective, mind-independent reality.
Hume and Kant were right to be sceptical of the idea that metaphysics could provide a direct, unfiltered pipeline to reality. What knowledge anyone has of the universe is grounded in experience and observation tempered by scientific enquiry. When our interest is in the nature of things we turn to the sciences. When our interest extends to the deep story about those things we turn to fundamental physics. Fundamental physics provides an account of the truthmakers for scientific claims generally. Although some readers will hear this assertion as an expression of a kind of extreme reductionism, I argue that it is not. Confusion on this point has muddied the water, inhibiting progress in metaphysics, pure and applied. One symptom of this is the unfortunate tendency to conflate epistemological issues bearing on explanation with issues in metaphysics. Another is the lingering reluctance to distinguish metaphysics from philosophy of language. Talk about talk about the universe is not talk about the universe.
But this is to get ahead of the story. Back to Kant. Kant was right in supposing that the aim of metaphysics is, or ought to be, to disclose our fundamental categories. These categories are not merely artifacts of ways we have of thinking about the universe, however, parochial cognitive spectacles, ripe for debunking by social psychologists and experimental philosophers. Categories are required for any intelligible thought about the universe. The mistake would be to imagine that this turns the universe, or the universe as revealed by science, into a construct.
1.3 Substance and Property
A central theme in what lies ahead concerns the nature of substances and properties. Substance and property are basic, indeed the basic, (p.4) ontological categories. Think of these categories as complementary: substances are property bearers; properties are ways substances are. Every substance is some particular way or other, every substance is propertied; every property is a particular way some substance is.
Spelling out this thesis requires starting with everyday commonsensical examples: billiard balls, trees, tables. Such familiar cases provide a sense of the categories, a grasp of what it is for something to be a substance or a property. With this understanding in hand, you can proceed to reconsider the everyday cases, the billiard balls, trees, and tables. When you do so, you discover that substances, as property bearers, must be simple. Substances of necessity lack constituents that are themselves substances. For their part, properties, ways substances are, must be properties of simples. From this, together with what we think we know about such things, it follows that billiard balls, trees, and tables are not after all substances, their apparent properties are not in fact properties. The substances are propertied simples, the fundamental things. This conception of substances and properties flows directly from the idea of substances as property bearers and properties as particular ways substances are.
You might worry that this narrow conception of substance and property yields a kind of scepticism or anti-realism concerning everyday, medium-sized objects and their properties. But to say that a billiard ball is not a genuine substance or that the billiard ball’s sphericity or redness are not genuine properties is not to say that there are no billiard balls or that it is false that this billiard ball is red and spherical. Truthmakers—truthmakers—for judgements about billiard balls and their colours or shapes are particular arrangements of the fundamental substances. (At least this is how it is if the universe comprises arrangements of fundamental particles. If the universe is continuous, then the truthmakers might be particular ways the universe-substance is. I shall leave aside this qualification for the moment, returning to it in chapter 2.)
So, a second theme advanced here is that we philosophers are not in a position to ascertain truthmakers for everyday judgements about the universe a priori. You can know the application conditions for talk of billiard balls, trees, and tables, you can know how to use the terms, and you can know that claims about billiard balls, trees, and tables are often true, without having any clear idea as to the nature of (p.5) truthmakers for judgements about such things. In particular, there is no hope of recovering or ‘reading off’ the character of the truthmakers from an analysis of the application conditions for terms deployed in science and in everyday life to state truths about the universe. Only in the case of fundamental physics do you begin to get at the deep story, the nature of the truthmakers.
In advancing this view, I do not take myself to be embracing a radical thesis, but merely to be echoing Descartes, Locke, Spinoza, and countless other philosophers from Plato and Aristotle through the medievals to the late eighteenth century. Locke, for instance, thinks that the real substances are the corpuscles. Billiard balls, trees, and planets are fleeting arrangements of these, substances by courtesy. Descartes holds that there is but one extended material substance, space itself. Billiard balls, trees, and planets are local ‘thickenings’ of space, ways space is. (I owe this way of putting it to Jonathan Bennett.) For both Descartes and Locke, ordinary objects are not substances; ordinary objects are, to a first approximation, modes, particular ways substances are arranged or space is configured. Neither Locke nor Descartes regarded this as casting doubt on billiard balls, tables, or trees. Judgements about such things can be, and often are, perfectly true. Their truthmakers, however, are not substances corresponding to ‘billiard ball’, ‘table’, ‘tree’. Truths about the universe do not require a substance corresponding to every singular term, a property corresponding to every predicate.
These topics are addressed in more detail in the chapters ahead. Here, the aim is only to fend off worries that I might be relying on premises concerning everyday objects and their characteristics to establish conclusions that, if true, would call those very premises into question. In getting clear about the universe, science and philosophy alike must begin, as Aristotle notes, with the familiar, the ‘manifest image’, and move to the unfamiliar, to the deep story. The deep story includes an account of the manifest image and why it is as it is. The manifest image is not, or need not be, false or illusory. Judgements about billiard balls, their shapes and colours can all be perfectly true. Such judgements can provide descriptions of the universe that we find indispensable.
So long as the goal is to produce true descriptions and explanations of phenomena of interest in everyday life and in the sciences (p.6) (save fundamental physics), taxonomies we deploy in such endeavours are, for the most part, entirely adequate. If you want to learn about trees, you consult the biologist, not the physicist. Yet there is an important respect in which the deep story about trees is what you would find were you to scrutinize trees through the lens of fundamental physics.
Again, this is not a reductive claim. This is not the claim that you could translate or analyse talk of trees into talk of electrons, quarks, fields. It is not the claim that you could replace biological taxonomies, concepts, or terms with taxonomies, concepts, or terms at home in fundamental physics. And it is very definitely not the claim that you could provide application conditions for biological or psychological predicates in fundamental physical terms. More generally, the suggestion is not that ‘higher-level’ judgements (or explanations framed in terms of these judgements) of the sort you find in the various sciences and everyday life could be translated into, or replaced by, judgements (or explanations) couched in the vocabulary of fundamental physics.
Thus, although it might be straightforwardly true that this billiard ball is red and spherical, the truthmaker for the claim is not the possession by a substance, a billiard ball, of a pair of properties, redness and sphericity. A billiard ball is not a substance, and its redness and sphericity are not properties.
Someone might complain that in treating substances as simples and properties as belonging only to these simples, I am making a hash of the ordinary notion of property: I am using ‘property’ in a technical, stipulated sense. Were that so, my conclusions would be uninteresting: there are properties (the ball’s redness and sphericity, for instance) and Properties-with-a-capital-P. Why should anyone care about those?
This misses the point. In treating a particular billiard ball’s redness and sphericity as properties of the ball, you are treating the billiard ball as a substance, as a one. Treating the ball as a substance and the ball’s redness and sphericity as properties of the ball is one thing, however, the ball’s being a substance, the ball’s redness and sphericity’s being properties, is another matter altogether. Suppose that the ball is, in fact, a particular dynamic arrangement of interacting substances. Then the ball is not a substance, but a mode, a particular way particular substances are arranged here and now: a particular arrangement of a (p.7) particular sort. The ball’s redness and sphericity are not properties but consequences of this arrangement: what you get when you arrange these substances in this way.
Take three matches and arrange them so as to form a triangle. The triangle—the truthmaker for ‘this is a triangle’—is these matches in this arrangement. You do not have the matches, with their properties, so arranged, plus a triangle and its properties. What goes for the triangle goes for the individual matches as well. You do not have these particles, with their properties, duly arranged, plus the matches and their properties.
We begin, as we must, with a common-sense conception of the universe that treats billiard balls as substances, property bearers, and redness and sphericity as properties of billiard balls. In pursuing the idea of substances as bearers of properties, however, we come to recognize that the common-sense conception contains the seeds of its own revision, revision in light of empirical discovery, revision in light of what we determine to be the deep story about billiard balls. We discover that billiard balls are not in fact substances, and properties we ascribe to billiard balls are not in fact properties. This is not to replace the notions of substance (as property bearer) and property with proprietary notions, but to recognize that plausible conceptions of substance and property mandate distinguishing between what we ordinarily treat as substances and properties and what the genuine substances and properties really are.
Talk of properties leads to thoughts of universals. Properties construed as universals have instances. A dozen billiard balls provide a dozen instances of a single universal sphericity. Although there is a place for talk of universals, truthmakers for such talk are fully particular. Properties are modes, particular ways particular substances are. One billiard ball’s sphericity is distinct from another’s. I prefer the traditional mode to trope, a term first deployed by D. C. Williams in a defence of a one-category ontology. ‘Trope theorists’, by and large, accept Williams’s conception of substances as ‘bundles’ of tropes. I side with Locke and with Descartes, who noted that properties standing aloof from substances would themselves be propertied substances.
We have general truths—about sphericity and redness, for instance—but truthmakers for these truths are particular ways the (p.8) universe is, particular ways particular substances are. Generality is an important and irreplaceable feature of representations. Theories as standardly formulated consist exclusively of general assertions. But truthmakers for general truths—general truths that have truthmakers—are particular ways the universe is. The universe includes no general or universal entities.
The current philosophical climate is not friendly to a conception of properties as modes. Many contemporary philosophers regard ‘property’ and ‘universal’ as synonymous. Of the few who accept properties as particulars, even fewer embrace the kind of substance–mode ontology advanced here. It was not always so. Many, indeed most, of our most venerated philosophers regarded properties as particular ways particular substances are.
The billiard ball is red and spherical, but the billiard ball is not a substance and, consequently, its redness and sphericity are not properties. If you take the billiard ball’s constituents—pretend for the moment that these are particles—and organize them just so, you have something of which it is true that it is a billiard ball, that it is red, that it is spherical. The organization is important. Differently organized, or widely dispersed, the billiard ball’s constituents do not amount to a billiard ball. This is easier to see in the case of a complex object, a watch, for instance. You need more than the parts to have a watch, you need the parts assembled in precisely the right way.
All this makes it appear obvious that fundamental ontology requires, in addition to substances and properties, relations. I admit that this is how it appears. I admit, as well, that we need relational predicates to say all we have to say about the universe. Relations are, in this regard, ineliminable. What I am not prepared to admit, however, is that relational truths require relational truthmakers. At any rate, this is not something I am prepared to admit without a fight. Truthmakers for relational truths could turn out to be nonrelational features of the universe. Were that so, a two-category—substance–property—ontology would provide all anyone could want by way of truthmakers for everyday and scientific truths.
(p.9) But why disdain relations? I follow a long line of philosophers, beginning with Aristotle, and running though the medieval period and the Enlightenment, who regarded relations as, at best, ontological anomalies. It is a measure of how far we have fallen that so few philosophers nowadays see any difficulty at all in the idea that relations have full ontological standing. ‘What’s the problem? There are relational truths; we quantify over relations; so we are ontologically committed to relations. No big deal.’
One of the aims of this volume is to encourage a visceral feeling for metaphysical hypotheses. Recent psycho-neurological studies suggest that metaphysics, ontologically serious metaphysics, is done in the gut, not in regions of the brain responsible for delicate, formal cognition (Below 1987). Metaphysical enquiry suffers when it is reduced to the kind of bloodless abstraction that results when metaphysics is replaced by conceptual analysis. Paraphrasing C. B. Martin (himself paraphrasing Locke), if you can’t live it, you can live without it.
The discussion in chapter 7 of the ontology of relations incorporates an attempt to make salient reasons philosophers prior to the mid-twentieth century were so often uncomfortable with relations. This does not amount to a disproof of relations, whatever that might mean, but it does serve to motivate the attempt to identify nonrelational truthmakers for relational truths. Relational truths most resistant to this treatment are truths concerning causal, temporal, and spatial relations. My hope is that by the time the topic of relations is addressed head-on, the road to a successful treatment of relations will have been paved by discussion of various other topics, including causation.
Truthmaking plays an indispensable role in the evaluation of ontological theses. You could think of truthmaking as an internal relation between a truth bearer—a judgement, a representation capable of truth or falsity—and some way the universe is, the truthmaker. To say that the truthmaking relation is internal is to say that, if you have the relata, if you have the judgement that snow is white and you have (p.10) snow’s being white, you thereby have the relation. An internal relation is (as D. M. Armstrong puts it) ‘no addition of being’. (It goes without saying that what it is for snow to be white could be, and assuredly is, a complicated matter.)
I do not regard truthmaking as a technical concept. A grasp of the notion of truthmaking goes hand in hand with a grasp of the notion of truth: each requires the other. Nor do I subscribe to the thesis that every truth requires a truthmaker. Mathematical truths and truths of logic are compatible with any way the universe could be. Mathematics and logic are informative, not in telling us how the universe is, but in enabling us to put two and two together.
Despite—or perhaps because of—its apparent obviousness, the notion of truthmaking has only recently come to be deployed self-consciously in discussions of metaphysical topics. In looking back over the history of various disputes in philosophy, however—disputes over the standing of relations, for instance—it is difficult to avoid the impression that, surprisingly often, philosophers, apparently at odds, were in fact struggling to say something like the same thing, struggling to identify truthmakers for truths of a particular kind.
Today confusion abounds in the philosophy of mind owing to the conviction that conceptually distinct truths require distinct truthmakers. The irreducibility of sociological, psychological, biological truths to truths of physics, however, provides no reason whatever to think that truthmakers for these truths could not be expressed in terms of fundamental physics.
This is a key point in all that follows. If you deny it, if you suppose that the impossibility of translating talk of flora and fauna, or talk of actions and emotions, into talk of electrons, quarks, and fields, shows either that there are no flora, fauna, actions, and emotions, or that these things must exist alongside, ‘above’, or in addition to, the quarks, electrons, and fields, you will find what I have to say here entirely unconvincing. My hope is that I can persuade impartial readers to share my conviction that metaphysics has been too long in the thrall of the linguisticizers, those who believe that deep truths about the universe are to be had by analysing ways we talk about the universe. Language takes us to the universe, to ways the universe is, but leaves open the nature of those ways. To discover that, we need science.
I have emphasized that the metaphysical picture defended here is of a piece with conceptions implicit in Locke and Spinoza—and, in whole or in part, in the work of many other historically influential philosophers. This might lead naturally to the thought that I am merely repackaging mistakes of the past. Metaphysics developed alongside science. But science has come a long way since Aristotle. The science of Locke and Newton is not our science. Why should anyone imagine that categories that worked well enough for the Milesians, the medievals, and philosophers in the Enlightenment would work in an era encompassing relativity and quantum mechanics?
Metaphysics, and in particular ontology, sets the limits of scientific theorizing, at least in this sense: in plotting basic categories of being, ontology constrains science. These constraints are not externally imposed rules. The constraints are the expression of principles we are all—including the scientists—bound to accept. Such principles are not based on armchair reflection, but on our ongoing give and take with being.
What of the Big Picture? The strategy of divide and conquer, often useful in solving complex problems, can be self-defeating in the case of fundamental ontology. The Big Picture is not a patchwork of a lot of little pictures. The little pictures (concerning the nature of properties and property bearers, causation, consciousness, and the like) are aspects of a Big Picture. In my own case, I discovered years ago in the course of wrestling with the problem of mental causation, that, like it or not, in ontology one thing leads to another. In practice this means that, in working out a fundamental ontology, you must be prepared to adjust and readjust accounts of particular topics in light of their implications for all the rest. This is the thought animating the chapters that follow.