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A Clarifying Synthesis for Scientific Methodology

CHAPTER 2: An Overview of the Source-Particular Model

The Source-Particular model is an attempt to ground empirical and theoretical frameworks within a system that justifies their existence. It is not meant to be revolutionary; rather, it is a method for producing knowledge revolutions. I first built it under the tutelage of my college advisor, Dr. Charley Dewberry, a philosopher and marine ecologist, and it has since grown from a sixty-page undergraduate thesis into more than two hundred pages of model-building. I am deeply grateful to the professors at Gutenberg College, and to Charley especially, for the grounding in the history of philosophy and the great books that made this work possible. Reading thinkers such as Thomas Reid, Michael Polanyi, Alasdair MacIntyre, David Hume, Immanuel Kant, Karl Popper, Aristotle, George Berkeley, and Charles Sanders Peirce — and this is far from an exhaustive list — gave me the raw material for a new synthesis. If that synthesis seems significant, the credit belongs less to any originality on my part than to the excitement of reconciling and extending ideas that have already stood the test of centuries.

I have always been fascinated by science, and a question I keep returning to is this: how should science operate — that is, if it is meant to give us knowledge (justified true belief) about the world? That is the methodological question: what is our scientific method? But that question quickly opens onto a deeper one: what makes a methodology good in the first place? If our scientific method turns out to be nothing more than an arbitrary convention, we are in dangerous territory, because arbitrariness is never a sound foundation for a model of anything.

Consider an example from the history of physics. Albert Einstein criticized Euclidean geometry for the way it abstracts away from any physical embodiment of its figures — Euclid, the Alexandrian mathematician working around 300 BC, produced the ancient world’s definitive book of geometric proofs without a single physical measurement in it (Euclid, Elements). When Einstein discussed Euclid’s Elements, he argued that a genuinely useful model of physical space needs some point of contact with physical evidence, not just internally consistent axioms (Einstein, Geometry and Experience, 1921). I do not want to overcorrect in the other direction and claim that abstract theories are only valid when they are tied directly to a dataset — quite the opposite. I raise Einstein’s critique only because it shows a thinker refusing to let a geometrical system drift into complete arbitrariness, which is a healthy instinct. My concern in this book, however, is with the far more common mistake, which runs the opposite direction: most scientific projects go astray not because they are too tied to physical assumptions, but because researchers discard their own biases and background assumptions at the laboratory door, as though those assumptions were not doing real work in shaping what counts as evidence in the first place.

If science is the foundation for many other fields of empirical, verifiable knowledge, then a poor foundation in science can cause the whole structure built on top of it to collapse. My aim in this book, then, is to provide a clearer foundation that can (1) ground our paradigm, (2) guide our research, (3) help us discover errors, and (4) guide the correction of those errors. Many methodologies fail to offer that fourth piece — a genuine procedure for error correction — even though it is essential to getting back on track in any field once something has gone wrong. Karl Popper’s falsificationism, for example, is an excellent tool for recognizing that some part of a theory is wrong, or that the theory is unfalsifiable and therefore empirically empty (Popper, The Logic of Scientific Discovery, 1934). In brief, falsificationism says that a theory only counts as scientific if it forbids some possible observation — if there is no experiment that could, even in principle, prove it false, then it is not doing scientific work. But Popper’s method, useful as it is, gives us no diagnostic tools for figuring out what specifically has been falsified within a theory, or whether the theory is worth salvaging in modified form, or whether we made a more basic mistake somewhere upstream. That gap was not Popper’s project — he was primarily responding to the logical positivists of his day — but it remains a serious absence in the methodological literature.

This lack of diagnostic capability becomes obvious once we look at real disputes in the history of science. Two examples, which I take up in depth in Chapter 11, are Werner Heisenberg’s rejection of Kantian causality and Albert Einstein’s rejection of Hendrik Lorentz’s ether. Heisenberg believed that quantum indeterminacy could overturn the Kantian assumption that every effect must have a determinate cause (Heisenberg, Physics and Philosophy, 1958). Einstein, for his part, kept Lorentz’s mathematical equations — which had originally been derived on the assumption that light traveled through a physical medium called the “luminiferous ether” — but stripped away the ether and gave the same equations an entirely new interpretation in his theory of special relativity (Einstein, “On the Electrodynamics of Moving Bodies,” 1905). I will develop both cases further later in the book, but the point to note now is that in neither case did the decisive shift turn simply on new observational evidence; something more like a change in background philosophical commitments was doing the work. Beyond this, most methodologies also fail to give the working scientist room to be a skilled craftsman and artist within a specialty — a skill that matters at every stage, from generating theories, to testing them, to evaluating them through peer review. I devote two full chapters to this idea (Chapters 8 and 9).

The inevitable result of trying to build a “method for methodologies” is that we are forced to answer both ontological questions (concerning the real essence of things, both internal and external to the self) and epistemological questions (concerning the theories by which we try to access that ontological reality). Philosophers usually treat ontology and epistemology as two separate specialties that can, in principle, be pursued independently. I do not think that separation holds up. The reason is simple: we cannot learn about what does not exist, and we cannot claim that something exists without some reason for the claim. There may be a degree of circularity built into this — we use our eyes to diagnose the eyes of others, and we use our own rationality to evaluate whether other people are reasoning well — but I think we should accept some circularity here rather than pretend we can escape it. The Source-Particular Model is likewise circular in this sense: we have to use the very tools the model provides in order to evaluate whether those tools are fit for purpose.

That circularity brings us to the heart of the model: an ontological taxonomy, or ranking system with built-in dependencies, that organizes our account of scientific theories. I call it the Source-Particular Model, and the name simply describes the groups of real things I have identified as meaningfully distinct from one another. To visualize the model, picture a three-by-three grid. Reading across, there are three levels, running from most foundational to most contingent: Metaphysical, Physical, and Surphysical.

Reading down, there are three categories that recur within each level: Source, Particulars, and Framework

A quick clarification before the grid itself: levels differ from one another in kind — the metaphysical, physical, and surphysical are different sorts of reality altogether. Categories, by contrast, differ only in aspect within a single level — the Source and the Particulars belonging to a given level are always the same basic kind of reality as each other, just playing different roles. I recognize the terminology is a lot to take in at once, but it becomes intuitive with practice, and three full chapters (3, 4, and 5) are devoted to walking through each level in turn. Here is the grid, with a short gloss of each cell:

	Metaphysical	Physical	Surphysical
Source (the container)	Mind	Spacetime	Environment
Particulars (the contained)	Variables	Matter	Complexes
Framework (the emergent metaphor)	Proposition	Motion	Narrative

Levels run left to right, from most foundational (Metaphysical) to most contingent (Surphysical). Categories run top to bottom: Source is the container, Particulars are the contained, and Framework is the new, non-literal thing that emerges when a Source and its Particulars are combined.

Let us build up an intuition for this grid from the “observer’s” point of view, following a path Immanuel Kant helped clear. Kant argued that human thought comes equipped with certain built-in structures — space, time, causality, and so on — that we bring to experience rather than derive from it. He called the world as it actually is, independent of our perceiving it, the noumenon (plural noumena), and he argued that we never have direct access to it. What we do have direct access to is the phenomenon: the world as it appears to us once it has been filtered through the built-in structures of our minds and the raw data of our senses. In Kant’s view, we never encounter objects “in themselves”; we only ever encounter our own interpretation of the effects those objects have on us (Kant, Critique of Pure Reason, 1781). Kant himself was fairly pessimistic about how much this phenomenal picture actually tells us about the noumenal world behind it. I want to push back gently on that pessimism. Drawing on the Scottish philosopher Thomas Reid, I think we have good reason to treat our senses as broadly reliable translators, not just an opaque screen: our senses take what are, at bottom, electrical signals firing in the brain and turn them into meaningful reports about states of affairs in the external world (Reid, Essays on the Intellectual Powers of Man, 1785). We all share this basic translating apparatus and our confidence in it — this is what “common sense,” in Reid’s technical use of the term, actually names. Reid’s translation still runs through the very same mental and sensory machinery Kant describes; the difference between the two thinkers is a difference in how much trust to place in that machinery, not a disagreement about whether it exists. Either way — whether we lean toward Reid’s confidence or Kant’s caution — using our senses at all requires a kind of prior faith, or at least a metaphysical commitment, that they are basically trustworthy. That is why I place our mental properties — the mind and its contents — at the foundation of the whole model, in the Metaphysical level.

This starting point matters enormously. If our metaphysical assumptions shape how we interpret everything we subsequently observe, then flawed metaphysical assumptions will produce a flawed science downstream, no matter how careful the experiments are. Fortunately, metaphysical claims work differently — and, in one sense, more securely — than physical ones. At the metaphysical level we can achieve genuine deductive certainty. To be precise about what I mean: I am not claiming that acquiring rational insight is as mechanical as solving an equation, nor that simply having a metaphysical assumption makes it true. What I am claiming is narrower: metaphysical reasoning is the only kind of reasoning capable of producing strictly deductive arguments — arguments in which true, certain premises guarantee a true conclusion by logical necessity. Only the metaphysical level yields “proofs” in this strong sense. Take a simple case: how certain can we be that 1 + 1 = 2? Totally certain — it follows from the definitions of the terms involved. Or take the law of non-contradiction, that a proposition X cannot be true and false (not-X) at the same time and in the same respect: this is close to true by definition. More elaborate claims, if they are deductively derived step by step from starting-points this basic, inherit the same certainty as their premises.

One useful way to test a metaphysical claim’s certainty is the reductio ad absurdum — showing that denying the claim leads to self-contradiction. Take the claim that our senses are basically trustworthy. Suppose we deny it and say our senses are entirely unreliable. To even assert that claim to someone else, we would need language, memory, and reasoning that are themselves delivered to us via our senses and cognitive faculties — so the very act of arguing against the reliability of our faculties presupposes enough reliability in those faculties to construct and communicate the argument. The claim undercuts itself. Or take a more radical skeptical scenario: perhaps a deceptive demon, or a simulator running our minds like software, manipulates all our beliefs (this scenario is most famously associated with Descartes, but far older versions of it appear even in Augustine’s City of God, Book XI). Suppose we grant, for the sake of argument, that such a deceiver exists. Even so, in order for the deceiver to deceive or manipulate someone, that someone has to exist as a subject capable of being deceived. So even under the worst-case skeptical scenario, we cannot be deceived about the bare fact that we exist. This is the famous Cartesian starting point — “I think, therefore I am” (cogito, ergo sum) — and from that single certain foothold, Descartes tried to build up further certainties one careful step at a time (Descartes, Meditations on First Philosophy, 1641). The Source-Particular Model borrows this same Cartesian starting point as its own metaphysical bedrock.

Before going further, I want to be precise about what I mean by “metaphysics,” since the term gets used in wildly different ways across the history of philosophy. I will use it to mean: whatever exists or holds true prior to experience — that is, whatever is not itself derived from empirical observation. To a committed naturalist, calling something “prior to experience” might sound like a polite way of saying it is second-rate, merely speculative philosophy dressed up as knowledge. I want to resist that inference. Every piece of scientific work is filtered through a subjective interpretive lens before it becomes “data” at all, and that lens itself can only be evaluated using arguments that have no empirical content of their own, even though those arguments are still substantive and rationally binding. The rationalist tradition is correct that our knowledge about evidence — what counts as good evidence, what a fair test looks like, what makes one explanation better than another — exists prior to any particular piece of evidence, whether we recognize that background framework consciously or only implicitly. Even if a rationalist turns out to be wrong about the strict order of events — even if, say, our sense of what counts as good evidence is itself an abstraction built up gradually from accumulated experience rather than something we are born with — it remains true that whatever metaphysical commitments we hold will shape how we read the evidence in front of us. Evidence gets fitted into an interpretive framework that already exists prior to the evidence’s arrival.

Here is a concrete historical illustration. Suppose I hold the geocentric belief that the Earth sits at the center of the universe. When I then observe planets tracing strange, looping paths across the night sky, I do not immediately conclude that my underlying belief is mistaken. Instead, I fit that data into the box marked “things moving around the Earth,” no matter how many extra epicycles — small looping sub-orbits bolted onto the main orbit — I have to add to make the model work. This is, in fact, exactly what happened historically: ancient and medieval astronomers added epicycle upon epicycle to the Ptolemaic (Earth-centered) model to keep it consistent with new observations. The geocentric framework was only seriously questioned once Nicolaus Copernicus argued, on largely aesthetic and metaphysical grounds, that a good and orderly God would more plausibly have arranged the planets in a simpler, more harmonious pattern than the baroque, ever-more-complicated geocentric scheme required (Copernicus, De Revolutionibus Orbium Coelestium, 1543). Notice that the initial case for heliocentrism was not first and foremost a matter of new telescopic data — telescopes did not exist yet — but a metaphysical judgment about beauty, simplicity, and divine orderliness. Beauty, parsimony, coherence, correspondence to a wider theory, and every other quality we use to assign value to a body of data are themselves metaphysical assumptions that precede the evidence they are used to evaluate.

The Cartesian “I think, therefore I am” is, again, the clearest possible example of a purely metaphysical claim. It assumes that there exists a mind — our mind — capable of holding and evaluating variables. By “variables,” I mean placeholders that are capable of later receiving specific empirical content (think of the x, y, and z of an algebraic equation: on their own they carry no empirical content, but real-world observations can subsequently be plugged into the slots they mark out). Variables come logically prior to any actual, concrete phenomena; they are the empty slots waiting to be filled, not the filling itself. If the mind is the container in which these variables reside, then the variables are the things contained within the metaphysical realm. Translating this into the model’s vocabulary: the mind is the Source, and the variables are the Particulars.

The Source-Particular (or, if you prefer more familiar language, container-contained) relationship recurs at every level of the model, as later chapters will show. One caution is worth flagging immediately: the container/contained language is a spatial metaphor standing in for what is really a non-spatial relation of dependency. Do not import literal container-logic — spatial containment, or debates about the curvature of physical space in general relativity — into the metaphysical level; the metaphor is meant to illuminate the dependency relation, not to claim that the mind is a literal box with variables literally rattling around inside it. If the container/contained language still feels confusing, feel free to substitute the more literal terms “prerequisite” and “dependent.” I prefer “Source,” though, because it foregrounds the asymmetry that matters most here: every Particular requires its Source in order to exist at all, but no Source requires any of its Particulars in order to exist — though, as I will explain shortly, a Source does need at least some Particulars in order to have any determinate meaning.

So what happens when the mind gets to work sorting through its variables? We arrive at axioms — the laws of logic, of mathematics, of causality, of sensory awareness, and of personal identity, through which all of our sense-data gets filtered. In the model’s vocabulary, this resulting propositional content is called the Framework, because it is what makes sense of the otherwise unrelated combination of a mind (the Source) and a variable (the Particular). Frameworks are, in Michael Polanyi’s sense, “metaphors”: new meanings that emerge from combining two or more ingredients that do not, taken purely literally, belong together at all (Polanyi, Meaning, 1975). Consider the ordinary sentence “the classroom was a zoo.” Taken completely literally, this sentence is absurd — there are no actual zebras, giraffes, ticket booths, or entry fees anywhere in the classroom. And yet an emergent meaning arises easily out of the cultural association most people share between “zoo” and “chaotic, noisy, and hard to control”: we instantly understand that the classroom was loud and unruly. The metaphor works precisely because it forces together two concepts — “classroom” and “zoo” — that do not literally overlap, generating a third meaning that belongs to neither concept alone. This is exactly the kind of move the Source-Particular Model makes at every level: combining a Source and its Particulars, which are different in kind from one another, to generate a Framework that is different in kind from either.

For the Metaphysical level specifically, “Source-Particular” describes the pairing of mind and variable. The mind, on its own, is not itself particular in any way; it is the general capacity to hold and relate variables. But putting mind and variable together produces new information that neither one supplies on its own — namely, propositions. A proposition, in this technical sense, is the mind’s own self-organization: its ontology, or, as Aristotle would say, its account of being qua being (being simply as being, considered in its own right, apart from any more specific subject matter) (Aristotle, Metaphysics, Book IV). This proposition-level meaning is a metaphor in Polanyi’s sense as well, though with one qualification: for Polanyi, metaphors are strictly statements that cannot be taken literally, not necessarily a pairing of two categories that cannot literally be reconciled with each other. Even so, I think the underlying mechanism is the same: our subsidiary (background, half-noticed) awareness of the parts metaphorically constructs a single focal (foreground, fully attended) awareness of the whole.

Focal awareness is whatever we are directly and consciously attending to at a given moment; it is the meaning that the various parts, taken together, communicate. Consider what it is like to ride a bicycle. Your focal awareness while riding is not the mechanical act of pushing each pedal, nor the constant small shifts of your weight to stay balanced, nor the tiny corrective turns of the handlebars. All of those actions are subsidiary — present, and even necessary, but not directly what you are attending to. Your focal awareness is instead something like “getting down this path” or “not falling over,” the larger purpose that all those unnoticed micro-adjustments are quietly serving. For Polanyi, this means the bicycle functions as a tool: an extension of your own body (Polanyi, Personal Knowledge, 1958). This point generalizes well beyond bicycles. Any tool — a hammer, a pair of glasses, a map, a textbook — is, in this sense, an extension of the body, because it extends the reach of our senses, our physical actions, or our reasoning. Tools change our very relationship to the world by widening the sphere of things we are able to act on or understand. And crucially, our focal awareness is never directed at the tool itself; it is directed at the point where the tool meets the world. When you write with a pen, you attend to the words forming on the page, not to the precise pressure of your fingers on the barrel.

We can also see this dynamic in cases where subsidiary awareness gets wrongly promoted to focal awareness, with poor results. Consider trying to drive a nail with a hammer while consciously fixating on exactly how your fingers are wrapped around the wooden handle. Because your attention is on the grip rather than on the nail, your swing becomes stiff and poorly aimed, and you are far more likely to miss. Once you have practiced enough that the grip becomes properly subsidiary again — something your hand simply “knows” without your having to think about it — your aim on the nail improves immediately. Strengthening our subsidiary skills, in other words, strengthens the focal performance those skills are quietly supporting.

With those three ideas in hand — metaphor, focal awareness, and subsidiary awareness — we can return to the Source-Particular Model itself. Our own everyday focal awareness naturally sits at the highest level and category of the model: the Surphysical Framework of Narrative, where we process our experience in its richest and most meaningful form. This is, experientially, the level closest to lived life. But how we process that experience is quietly governed by the more foundational, more abstract levels beneath it — levels we can only access by deliberately turning our attention away from our ordinary focal awareness and toward the usually-subsidiary machinery underneath. This produces a kind of mirror-image structure in the model: certainty runs from the lower levels up to the higher ones (the Metaphysical level is the most certain, the Surphysical level the least), while focal, lived awareness runs from the higher levels down (we live our lives at the Surphysical level, only rarely attending consciously to the Metaphysical assumptions beneath it).

To round out this set of Polanyian tools, we need one more concept: tacit knowledge, meaning the kind of pre-understanding that lets us do things we cannot fully articulate (Polanyi, Personal Knowledge, 1958). Tacit knowledge explains why we can ride a bicycle without being able to state the physics of gyroscopic stability that keeps us upright, or the precise sequence of muscular corrections our body is making thirty times a second. We might hold only a vague, intuitive picture of what riding involves, or we might be trained mechanical engineers who understand the physics and material science of bicycles in exhaustive technical detail — the metallurgy of the frame, the manufacturing history of the brand, the record times of the best competitive riders, and so on. All of that additional knowledge can enrich our understanding of “riding a bicycle” to varying degrees, but none of it, by itself, constitutes the actual riding. Riding a bicycle is not identical to the physics of the bicycle’s motion, nor to the anatomy of the rider’s muscles. Riding a bicycle, in the vocabulary of this model, is a Narrative — a higher-level Framework that draws on, without being reducible to, everything beneath it.

But is “riding a bicycle” really a metaphor in the relevant sense? After all, what is incoherent or non-literal about the plain sentence “I am riding a bike”? We really are the ones riding it — aren’t we? Here is the twist: what is actually happening, according to the model, is that a mind is interpreting a stream of phenomena as “riding a bike.” The physical matter involved really is arranged into shapes we call a bicycle and a rider. But neither “the bicycle” nor “the rider,” considered as unified, meaningful wholes with a function and a story, exists at the purely metaphysical level (which contains only mind and variables) or at the purely physical level (which contains only spacetime and matter, without any reference to purpose or function). The bicycle-and-rider-as-a-meaningful-unit is therefore a distinctly Surphysical construct. “A biker” implicitly invokes particular complexes (a physical bicycle object, a physical human body) together with a Source that makes those complexes cohere into a single meaningful whole — namely, an environment: the trail, situated within a park, situated within a city, that gives the whole scene its point. Understood this way, “biking” is indeed a metaphor — not the everyday kind that a literal reading of the sentence would obviously flag, but the deeper kind revealed once we notice the ontological gap the sentence is quietly papering over.

This bicycle example reveals something about the model I have not yet stated outright: the Source-Particular structure applies not only within each level, but across the three levels taken together, on a larger scale. Metaphysics, Physics, and Surphysics themselves form a Source, a Particular, and a Framework at the macro-scale of the whole model. Metaphysics provides the container (mind) within which physical things can first be conceived of and related to one another at all. The relating of physical things, in turn, gives rise to environments, complexes, and narratives — the Surphysical Framework layer. I recognize this may be a large claim to absorb this early in the book, and I will return to unpack it more fully in later chapters.

Return once more to the cyclist. Nothing resembling a bicycle or a biker exists at the purely Metaphysical level; that level exists prior to any physical thing being singled out as an object at all. And yet the bicycle example shows that even though our only immediate access is to the Narrative level of our own lived experience, that experience is always quietly informed and constrained by the more foundational levels beneath it. The rider is not focally aware that he is pedaling, yet some form of understanding of pedaling is clearly present and available to further reflection or practice. In the same way, we are not ordinarily, focally aware of our own metaphysical assumptions — but we can bring them into view and examine them through models like this one, which are designed to make visible the usually-hidden subsidiaries beneath our knowledge. This has always been one of philosophy’s central and most valuable roles: not to replace our lived experience, but to clarify, piece by piece, the largely invisible scaffolding that makes that experience possible in the first place.

CHAPTER 3: The Metaphysical Level

No thinker illustrates the Metaphysical level better than Aristotle. Although the title of his treatise Metaphysics arose from a fairly arbitrary bit of ancient library cataloguing — it was simply shelved “after the Physics” (meta ta physika, literally “after the physical things”) — the subject matter turns out to be deeply relevant to physics itself. Aristotle describes this “new science” as the discipline that investigates first principles and causes: the discipline concerned with the attributes of being as such, what he calls ousia, or substance, and what later commentators summarize as the study of “being qua being” (Aristotle, Metaphysics, Book IV, Ch. 1). Aristotle notes, somewhat wryly, that this kind of inquiry tends to flourish historically whenever a society has enough leisure to support philosophers who can pursue it for its own sake rather than for immediate practical need. Early in the Metaphysics, he calls this inquiry into substance the discipline closest to the divine, on the grounds that it is exactly what a god would be occupied with: a god, on Aristotle’s view, is above all the ultimate cause and knower of all things.

Aristotle’s word “science” here should not be confused with our modern, narrower sense of “science” as controlled empirical experimentation. For Aristotle, episteme (often translated “science”) simply means any organized discipline aimed at genuine knowledge, whatever its subject matter. Aristotle explicitly holds that some knowledge is never going to be empirical knowledge at all — that some categories of reality cannot, even in principle, be reduced to matter. His entire Metaphysics is an attempt to work out this non-empirical kind of knowledge in detail. In fact, Aristotle argues that truly knowing something requires more than identifying the matter it is made of: we also need to identify its efficient cause (what brought it about), its formal cause (what shape or structure makes it the kind of thing it is), and its final cause (what it is for). I will unpack all three shortly with a concrete example. Much of the Metaphysics, whether explicitly or implicitly, works out a whole family of a priori concepts — concepts known prior to or independent of experience — including the four causes, the law of non-contradiction, the idea of an uncaused first cause, and criteria like parsimony (preferring simpler explanations), consilience (the way independent lines of evidence converge on the same conclusion), pragmatism, correspondence (truth as matching reality), coherence (truth as fitting together consistently with everything else we hold), the puzzle of infinite regresses, and the basic nature of truth and cognition.

To treat any of these concepts as ultimately reducible to matter, Aristotle argues, is to commit a category error — to mistake one kind of thing for a fundamentally different kind of thing. He makes this point vividly: “wood does not manufacture a bed” (a paraphrase of the reasoning found across Metaphysics, Book VII). Consider a wooden bed built by a craftsman. First, a purely materialist account is missing an efficient cause: what actually moved the wood into the shape of a bed? Wood does not spontaneously assemble itself; some agent — the carpenter — had to act on it. Second, it is missing a formal cause: what, exactly, is “the form of a bed”? That form cannot simply be identified with any one of the bed’s physical constituent parts (the planks, the nails, the fabric), since those same materials could just as easily have been assembled into a chair or a ladder. If matter were truly all there is, then no arrangement of matter would have any privileged claim to be “the shape of a bed” rather than any other shape. Third, it is missing a final cause: there is no built-in purpose, function, or reason for a bed’s existence written into the wood itself. If a random pile of particles happened by pure accident to take on the shape of a bed, it would only count as “a bed” because a mind was there to recognize and use it as one — not because bed-ness is a real property the particles possess independently of anyone’s noticing it. For Aristotle, natural things like an acorn carry their final cause within themselves — an acorn naturally develops into an oak tree, without anyone designing it to do so — whereas artifacts like beds have their final cause located instead in the mind of the person who made them. Whichever kind of case we are dealing with, Aristotle’s broader point stands: a purely materialist account cannot even formulate the question of purpose, let alone answer it, because it has no vocabulary in which purpose could be expressed as a real feature of the world. On this view, matter alone cannot account for change, form, or purpose.

It would therefore be a mistake to assume that empirical, laboratory-style knowledge is automatically more certain or more solid than this kind of philosophical knowledge — that assumption misunderstands what human reasoning is actually doing. We take it for granted, for instance, that a single thing cannot both exist and not exist in the very same respect at the very same time (the law of non-contradiction) — yet this is not itself an empirical discovery made in a lab; no experiment could ever confirm or disconfirm it, because it is presupposed by the very possibility of running and interpreting any experiment at all. We likewise take for granted that composite objects — a human body, a river, a nation — retain a stable identity even as their individual parts are gradually replaced or altered over time. And we take for granted that causes really do produce effects (a point Kant develops with particular care). All of these are metaphysical commitments, quietly operating beneath every empirical inquiry we conduct.

Accepting commitments like these, I want to argue, inevitably implies the existence of a mind as their ultimate source. Within the Source-Particular Model’s three-part structure, the mind functions as the epistemic cause underlying all other causes we might identify: it is the container that makes all other knowledge possible, and in that sense it is the most fundamentally real thing in the system, both ontologically (in terms of what actually exists) and epistemologically (in terms of what we can actually know). One of the broadest points of agreement across the whole history of philosophy — as Georg Wilhelm Friedrich Hegel likewise observed — is simply that there is something rather than nothing, and that philosophical inquiry has to start from whatever is immediately given to us, rather than from some further, more basic starting point (Hegel, Science of Logic, 1812). Exactly who or what “the observing party” ultimately is remains open to debate. But if that observing party is describable as an “I” at all, then that “I” cannot be mistaken about its own existence — that is the one thing it is logically impossible to be deceived about, since being deceived already presupposes a subject there to be deceived. This is not merely deductive certainty (certainty that follows from prior premises); the Source-Particular Model treats it as axiomatic certainty — certainty so basic that it functions as a starting point rather than a conclusion.

And yet, notably, we did not arrive at this truth by reasoning it out in advance of any experience at all. Metaphysics, on my account, studies the ontological conditions that make all other knowledge possible — but we typically arrive at an explicit grasp of those conditions only by reflecting backward from experience we have already had, not by deducing them from nothing beforehand. On Kant’s account, we never have unmediated access to either pure reason on its own or pure raw experience on its own; instead, we receive an already-fused phenomenal synthesis, and it is only by careful philosophical analysis afterward that we can distinguish the contribution of the mind’s own structuring from the contribution of whatever lies “outside.” Even so, for all practical purposes, the resulting phenomenon — the world as it appears to us — is the real substance we actually care about and can meaningfully discuss. It is a common misconception that this Kantian picture is flatly opposed to Reid’s realism. On closer inspection, Reid actually agrees with Kant that we lack any direct access to things exactly as they are “in themselves”; both thinkers hold that, as finite subjects, we have only our own cognition to work with, and that we must extract whatever metaphysical conclusions we can from the accumulated deliverances of experience. The real difference between them is a difference in the degree of trust each is willing to place in that experience as genuinely corresponding to an independent reality. For Reid, our senses and our shared natural language are gifts specifically suited to letting us understand the external world by means of the “signs” our senses present to us; Reid is explicit, in his writings on the philosophy of common sense, that God designed our faculties precisely so that we could correctly interpret the signs of the world beyond our own minds, and this theological confidence is what underwrites Reid’s greater trust in the senses compared to Kant’s more guarded position.

Within the Source-Particular Model, then, “experience” is never merely the isolated mind turned in on itself; it is the entire chain running from mind, to observation, to narrative. We have to postulate that the Physical level — much like Kant’s noumenal world — is genuinely real, even though it is never directly accessible to us in an unmediated way. Whichever picture one ultimately prefers, Reid’s or Kant’s, both end up tracking the very same three-part structure this model proposes. I will not spell out the full mapping in detail quite yet, except to flag it briefly: the Metaphysical level corresponds to the a priori structures of natural language and common sense; the Physical level corresponds to the noumena, the reality that is signified but never directly seen; and the Surphysical level corresponds to the phenomena, the signs through which that reality is indirectly communicated to us.

When we turn to describing the Metaphysical level in the model’s own vocabulary, three categories with their own distinctive qualities come into play — as is true at every level: Source, Particulars, and Framework. Because this is fundamentally a mental realm, the mind plays the crucial role of Source: the space within which the Particulars can exist at all. It plays this role not by creating the Particulars from nothing, the way an author might invent a fictional character, but rather by sustaining them — serving as their ongoing “life-blood,” the condition without which they could not persist. Strictly speaking, we could imagine each of the model’s categories in total isolation from the wider contingency structure, but in practice it becomes very difficult indeed to imagine concepts existing with no mind to hold them, or physics operating outside of any spacetime, or a subject existing with no context at all. The Source is, in this sense, always implicitly assumed by our very language, whether we notice it or not.

Take the word “nothing” as an illustrative case. “Nothing” is meant to describe the absence of either a container or its contents. And yet we cannot construct a linguistically coherent use of “nothing” that makes no reference, even implicitly, to some Source. If I say “nothing is here,” or “nothing happened,” or “nothing happened here,” each of these statements is implicitly framed against a background of spacetime — a “here” or a “when” against which the absence is being measured. Even if I retreat further and try to speak of “nothing” in a purely abstract sense, entirely apart from physical substance, that abstract “nothing” is still occurring as a thought — which is to say, it is still something occurring within a mind. Even the total absence of any thought presupposes a thinker capable of having (or, in this case, not having) that thought, in the same way that the absence of light only makes sense relative to some possible source of light. If this reasoning holds, then not even “nothing” — let alone any particular “thing” — can be conceived apart from some mental context in which it is conceived.

If a mind really exists, and we ask what exactly it is, the most straightforward way to answer is to look at what it does: it senses, remembers, experiences, acts, exercises skill, and so on — in short, it has thoughts. And the crucial feature of a thought, for our purposes, is not merely that it occurs, but that it is about something; philosophers call this feature “intentionality,” or “aboutness.” A thought that is about something is already implicitly a system of variables organized into candidate proofs — proofs that are capable, in principle, of corresponding to real states of affairs, and that are, in a real sense, themselves genuinely existing entities once true. And yet, importantly, at the purely Metaphysical level there is no correspondence relation available to us at all (no way to check a claim directly against an external physical fact) — there is only internal coherence, meaning consistency among the claims themselves. This is precisely why claims at the Metaphysical level are not falsifiable in Popper’s sense: falsifiability requires that some possible empirical observation could count against a claim, but no empirical observation of any kind bears on purely metaphysical claims like the law of non-contradiction.

The only way to test claims that belong exclusively to the mind, then, is to test them against the absurdity of their opposites (the reductio ad absurdum technique introduced earlier) and to build further propositions from them by strict deduction. This procedure can strike many readers as arbitrary or even circular. In fact, I want to argue the opposite: this Metaphysical mode of reasoning yields the most certain and most secure knowledge available at any level of the model.

The Particulars at this level are variables: the smallest indivisible units out of which logic, mathematics, grammar, and reasoning generally are built. They are the most basic, “irreducible” elements available within our mental constructs. On their own, variables signify nothing at all except pure relation — a placeholder standing ready to be related to other placeholders according to some rule. All the metaphysical truths available to us share this same character: they are pure relations, in the sense that they are not yet tied down to any particular external object or physical construct. “Relation” here means holding some determinate value or ordering with respect to other variables. In this sense, the Metaphysical level is specifically the level of value and of the ordering of values. Because values and their orderings can apply equally well, in principle, to any number of different objects, variables themselves never automatically “particularize” into any specific material form; they remain generic until something further fills them in.

Ethics offers an interesting borderline case here. In one sense, ethics genuinely participates in metaphysics: “good” and “bad,” considered purely in the abstract, are themselves a kind of value, and values belong at the Metaphysical level. But there is clearly more to concrete moral judgment than abstract value alone. Moral claims certainly have to conform to basic metaphysical considerations, but they must also correspond to specific actions, carried out by a particular agent, working through a physical medium, within a specific environment and context. Ethics, understood this way, moves beyond the tidy certainties of the Metaphysical level into the messier, richer, and less certain territory of Narrative — which, in this model, belongs to the Surphysical level. Meanwhile, other purely metaphysical items, like numbers or the rules of semantics, seem to have no direct bearing on physical laws or chemical reactions and yet somehow still apply cleanly to them whenever we use them to describe the physical world. In one sense, a variable is applied to some physical or surphysical concept only somewhat arbitrarily, as a matter of notational convenience — and yet, in another sense, real meaning is clearly being communicated when we do this. If that were not so, it would be impossible for two people to genuinely agree or disagree about a mathematical or logical claim concerning the physical world; disagreement itself presupposes shared, meaningful content to disagree about.

This raises an obvious question: what exactly is this abstract realm that can be laid over our empirical findings — organizing them, illuminating them, and helping us judge them true or false — while apparently existing quite separately from the physical world itself? Many mathematicians have puzzled over exactly this question. In his celebrated paper on the subject, the physicist Eugene Wigner argued that the sheer effectiveness of mathematics in describing the physical world is genuinely puzzling — “a wonderful gift which we neither understand nor deserve,” bordering on the mysterious (Wigner, “The Unreasonable Effectiveness of Mathematics in the Natural Sciences,” 1960). In response, others, such as the mathematician Richard Hamming, have suggested that mathematics only looks so effective because we quietly discard whatever mathematics turns out not to correspond well to nature, keeping only the successful cases and thereby creating a kind of survivorship bias (Hamming, “The Unreasonable Effectiveness of Mathematics,” 1980). But this response, I think, only pushes the question back a step: it still has to explain why there is any body of mathematics that corresponds this well to nature in the first place, and to such a strikingly serendipitous degree.

If mathematics really were a completely abstracted discipline, entirely foreign to our material existence, such that its correspondence to nature were simply a coincidence, then that coincidence would indeed be a genuinely inexplicable anomaly. The Source-Particular Model, however, offers a different diagnosis: it denies that abstract mathematical concepts are somehow derived by abstraction from physics and surphysics in the first place. Instead, on this model, the abstract Metaphysical level is precisely the interpretive lens through which we filter and organize our sense experience to begin with — it is not extracted from experience after the fact, but is presupposed by experience from the start. A committed materialist could, in fact, accept a version of this same point: our brains have simply evolved to interpret the world in a way that happens to line up well with how the world actually behaves, so it should be no surprise, on this view, that our mathematical interpretation of the world maps onto the world reasonably well. On this reading, the correspondence between mathematics and nature is close to a tautology, since we use mathematics to organize our experience of nature in the first place, prior to doing any formal natural science with it at all.

This may be part of why Kant himself remained skeptical about our ability to know the noumenal world directly: not only do we lack any unmediated experience of it, but what we do experience turns out to be suspiciously well matched to the very interpretive tools we bring to the table beforehand, which should perhaps make us cautious rather than confident. And yet, paradoxically, this same striking correspondence might instead give comfort to a realist like Reid: if our senses and our intuitions line up with the physical world this well, one very natural explanation is that they were specifically designed to line up that way. Which conclusion one is drawn to — Kantian caution or Reidian confidence — will likely depend on one’s prior views about divine design, and on one’s general willingness to accept an outcome that looks, on its face, highly improbable. At the very least, we can say with confidence that we possess a set of variables that reliably track our analyses of matter and of the higher-level complexes built out of matter.

More specifically, these variables line up with higher-level reality through the alignment of Frameworks across levels. Picture a set of transparent anatomical overlays of the human body — one sheet showing the digestive system, another the nervous system, another the skeleton — that can be layered on top of one another to build up a single, complete picture of the whole body. In much the same way, the different levels of reality in this model line up and overlay one another to produce a fuller, more complete account of reality as a whole.

At this exact juncture, I think, the real limitations of pure naturalism come clearly into view. Whether one chooses to interpret the “unreasonable effectiveness” of mathematics as a tautological by-product of evolutionary history, or instead as a meaningful piece of evidence for cosmic design, depends entirely on the metaphysical commitments one brings to the question beforehand — the raw empirical correlation between mathematics and nature is, by itself, silent about its own ultimate origin. For the naturalist, the alignment is simply a brute material necessity that requires no further explanation; for the teleologist (someone who thinks the universe exhibits genuine purpose, or telos), that same alignment is a significant sign pointing toward design. Our underlying Frameworks inevitably govern how we interpret every individual piece of data we encounter, which shows that we do not simply derive our metaphysical grounding from scientific observation, as a strict empiricist might hope; rather, we conduct our science by means of metaphysical commitments we already hold. If this is correct, then the naturalist, in order to exclude a metaphysical origin for reality, has no choice but to rely on metaphysical commitments of their own to rule that possibility out — which means the naturalist is not actually avoiding metaphysics at all, but only reducing it, by stipulation, to purely material terms. In effect, naturalists cede the genuine ground of metaphysics through what they actually do in practice, even while officially disclaiming metaphysics in their stated doctrines.

At this point it is worth pausing to explain more carefully how Frameworks operate at the Metaphysical level, and in the model generally. First, it is important to be clear that a Framework is not “emergent” in the sense of being built up piece by piece out of its Particulars, the way a wall is built up out of individual bricks. Instead, a Framework is the relationship that holds between two otherwise irreconcilable categories, forming a proper “Source-Particular” pairing: it is a genuinely new, emergent property arising from the interaction between the two prior categories within a single level of reality, rather than something assembled additively from parts. The Framework, in other words, arises from a metaphor, not from mere aggregation. At the Metaphysical level specifically, the mind is categorically distinct from the variables it contains, even though those variables depend on the prior existence of the mind as their Source. The mind is not literally made up of a collection of variables, in the way a wall is made up of bricks; nor are variables literal pieces of the mind, the way a brick is a piece of a wall. And no particular arrangement of mind and variables, however elaborate, can by itself push their relationship into a higher category than the Metaphysical. The laws of logic, for instance, do not depend solely on any particular mind’s actually operating them at a given moment; rather, the operation of minds in general is what makes it possible for categories — that is, stable units and unified groupings — to exist and be used at all. The mind facilitates model-building in general. But without variables — without something for the mind to categorize in the first place — there would be nothing for any Framework to organize, and so no Framework could arise.

Throughout this book I draw on several concepts from Michael Polanyi, especially from his posthumously published work Meaning (1975), which I have not yet fully unpacked. These concepts — metaphor, focal/subsidiary awareness, and tacit knowledge — recur throughout the model, since so much of my own thinking here has been shaped directly by Polanyi’s influence. To restate the definition of metaphor precisely: a metaphor arises when (1) the literal meaning of a statement is absurd or incoherent on its face, prompting the mind to seek out a new, non-literal meaning instead, and (2) that new meaning takes on distinctively subjective, symbolic qualities drawn from shared cultural or experiential context. Returning to our earlier example, “the classroom was a zoo” counts as a metaphor precisely because its literal meaning is absurd (there are, again, no actual zebras or entry fees involved), yet an emergent meaning is readily available from the shared cultural association between “zoo” and “chaotic, noisy, animal-filled place.” A metaphor like this builds directly on our prior, independent understanding of both of its component concepts — “zoo” and “classroom” — fusing them into a single new meaning that neither concept, alone, could supply.

The Metaphysical level’s own “Source-Particular” pairing — mind and variable — is doing a structurally similar kind of work. We are merging two ideas that, taken purely literally, do not belong together: a mind is not itself a variable, and a variable is not itself a piece of mind. And yet their combination generates genuinely new information in our thinking — namely, propositions. Propositions, again, are abstract: they are the mind’s own self-organization, its account of its own being, or, to use Aristotle’s phrase once more, its grasp of “being qua being” — that is, whatever must hold true for anything at all to exist, prior to any further specification of what particular kind of thing it is. This, I am suggesting, is itself a kind of metaphor, though I should flag one difference from Polanyi’s own usage: for Polanyi, metaphors are specifically statements that resist a literal reading, not necessarily any pairing of two categories that cannot be literally reconciled with one another. Still, in a broader sense, I think all of our subsidiary awareness works by metaphorically constructing a single focal awareness out of parts that, considered on their own, do not obviously add up to that focal whole.

Bring this back once more to the model as a whole. Our own immediate, everyday focal awareness sits at the model’s highest level and category — the Surphysical Framework of Narrative — where we process our experience in its richest, most integrated, and most meaningful form. This is, in that sense, the level truest to lived experience. And yet how we process that experience is quietly dictated by the more foundational levels beneath it, levels we can only bring into view by deliberately attending to what is more and more abstract, moving in the opposite direction from our ordinary focal awareness. Even though our everyday awareness sits about as far as possible from the mind considered in its bare, Metaphysical sense, that same bare mind remains the single most certain and most foundational element of the whole model — both epistemically (in terms of what we can be most sure of) and ontologically (in terms of what actually grounds everything else). This produces the mirrored structure I mentioned earlier: certainty increases as we move from the higher levels down toward the Metaphysical level, while immediacy and focal awareness increase as we move from the Metaphysical level up toward the Surphysical.

We have now covered metaphor, focal awareness, and subsidiary awareness. Understanding tacit knowledge is the key to understanding how the Source-Particular Model actually operates in practice. Tacit knowledge is a kind of pre-understanding: it explains why we are able to ride a bicycle without knowing the underlying mechanics or techniques involved, simply by performing the act successfully. We might carry only a fuzzy, intuitive picture of what riding a bicycle involves — or we might be trained engineers, fully versed in the physics and engineering of bicycles and in how a rider’s body ought to move in response. We might even know the specific metals, plastics, and fabrics that go into a given bicycle at the level of chemistry; we might know the various manufacturers who produce them and how; we might know the best and worst competitive riders in the sport’s history, along with the whole array of formal and informal competitions built around cycling, and whatever further trivia one could imagine. All of this additional knowledge can enrich — sometimes considerably — our focal awareness of what it means to ride a bicycle. But none of it, individually or collectively, simply is the riding itself. Riding a bicycle is not reducible even to the complete physics of the bicycle’s motion, or to the complete anatomy of the muscles involved in pedaling and balancing. Riding a bicycle, on this model, is therefore best understood as a kind of Narrative.

But is riding a bicycle really a metaphor at all? How exactly is the plain statement “I’m riding a bike” incoherent, or non-literal, on its face? We really are the ones riding the bike — aren’t we? The answer, on this model, is: not quite, or at least not in the naively literal sense the sentence suggests. What is actually happening is that a mind is undergoing a stream of phenomena that it interprets as “riding a bike.” The physical matter involved really is arranged into the shapes we call a bicycle and a human body. But strictly speaking, neither “the bike” nor “the rider,” understood as unified, meaningful, functioning wholes, exists purely at the Metaphysical level (mind and variables alone) or purely at the Physical level (spacetime and matter alone). What we are calling “a biker,” then, is a genuinely Surphysical construct. “A biker” implies particular complexes — the physical bicycle, the physical rider — together with a Source that makes those complexes cohere into a single meaningful whole: namely, the environment of the trail, situated within the park, situated within the city, that gives the whole activity its point and context. If this analysis is correct, then “biking” really is a metaphor after all — not the everyday, obviously non-literal kind of metaphor a casual reading of the sentence would flag, but a deeper metaphor rooted in the ontological gap between the model’s separate levels, one that ordinary language quietly papers over without our noticing.

In working through this example, I have already shown you something about the Source-Particular Model that I have not yet stated explicitly. There is one further, special layer to the model. The three levels themselves — Metaphysics, Physics, and Surphysics — form their own Source, Particular, and Framework at a larger, macro scale. Metaphysics provides the container within which physical things can first be held and related to one another as objects of thought at all. The relating of those physical things to one another, in turn, gives rise to environments, complexes, and narratives — the full Surphysical layer. I recognize this may feel like getting ahead of ourselves this early in the book; I will return to develop the point more fully in later chapters.

Return once more to the cyclist. Nothing resembling a bicycle, or a biker, exists at the purely Metaphysical level — that level exists prior to any physical thing’s being singled out as a determinate object at all. And yet the bicycle example shows that even though our only truly immediate access is to the Narrative level of our own lived experience, that experience is always quietly informed by the more foundational levels beneath it. The rider need not be focally aware that he is pedaling in order for some understanding of pedaling to be genuinely present, available for further reflection or refinement through practice. In the same way, we are not ordinarily, focally aware of our own metaphysical assumptions — yet we can bring them into explicit view through models like this one, which are built precisely to surface the ordinarily hidden subsidiaries beneath our knowledge. By acquiring a fuller and more accurate picture of these subsidiaries, we put ourselves in a position to build better diagnostic tools for correcting our errors and navigating toward truth. This has been philosophy’s central and most valuable role since its very beginning.

CHAPTER 4: The Physical Level

The Physical level is, in one sense, the most obvious and intuitive of the three, and in another sense the most controversial. Even though this level (along with, occasionally, the Surphysical) is often the only level of reality a strict materialist is willing to accept as real at all, there is nonetheless real hesitation, even among materialists, about how exactly to divide this level into its own Source, Particular, and Framework. What is the ultimate substratum of physics? Is it quantum fields? Is it spacetime itself? Is it some more abstract mathematical vector space? Is matter best understood as the curvature of spacetime, in the manner of general relativity, or as the excitation of underlying quantum fields? And what, at bottom, is physics itself — is it something fundamental that exists prior to the universe, or is it, like some naturalists claim about logic and mathematics, merely a convenient after-the-fact abstraction, built up to fit the patterns of observation the philosopher David Hume described as mere habit or custom? These are serious questions that any genuinely ontological model has to confront directly rather than sidestep.

We can say a few things at the outset about how the Physical level differs from the Metaphysical level already discussed. Two differences stand out in particular: (1) the Physical realm is finite, where the Metaphysical realm (of pure logical and mathematical relation) is not, and (2) the Physical realm proceeds by induction — drawing general conclusions from a limited set of specific observations, always open to revision by future evidence — rather than by the strict deduction available at the Metaphysical level. This means that whatever we identify as the Physical level’s Source, Particular, and Framework, physical reality as a whole must exhibit finitude, and therefore changeability, and therefore falsifiability — which, recall from Chapter 2, is the gold standard for any genuinely empirical, inferential body of knowledge.

With those two constraints in view, we can ask what the Physical Source actually is. We are looking for something finite that is nonetheless capable of holding finite particulars within it. The best candidate is spacetime. A pure mathematical vector space will not do, because vector spaces are typically infinite in extent, whereas we need something bounded. Quantum fields will not do either, because fields themselves already presuppose some more basic physical setting they operate within and depend on — they are too narrow a candidate to serve as the ultimate container. Spacetime, by contrast, satisfies both requirements: both space and time, as we ordinarily conceive them, are finite dimensions. You cannot meaningfully describe two particulars as separated by an infinite distance or an infinite duration within an ordinary spacetime framework the way you could within a purely abstract, infinite mathematical space. Spacetime also differs from the Metaphysical level in another important respect: it is not itself intrinsically changeable, even though things within spacetime change constantly. Within any given physical Framework, the specific arrangement of spacetime is altered by the events occurring within it, but the underlying nature of spacetime itself — as the finite, four-dimensional stage on which those events occur — remains constant across all such changes.

Having now discussed the two most fundamental Sources in the model — mind at the Metaphysical level, spacetime at the Physical level — we can test an interesting structural prediction. If mind really is more certain than even its own Particulars, as the Cartesian and Augustinian argument from Chapter 3 concludes, then we should expect a similar pattern of relative certainty to recur at every level: in each case, the Source of a level should turn out to be more fundamental — and, in an important sense, more certain — than the level’s other categories. And indeed, this rhyming pattern does appear to hold: spacetime, being less bound to any one specific physical configuration and more universal than any of the particular material objects it contains, turns out to be more certain and more fundamental than those objects. If the model is correct, we should expect this same rhyming structure to recur across every level’s set of three categories.

Let us test the rhyme again, this time at the level of Particulars. A variable, the Metaphysical Particular, represents a consistent placeholder value running throughout a given logical or mathematical proposition; it carries a distinctive kind of universality, in that any specific, “accidental” content can be substituted into it without changing the overall logical structure of the framework it belongs to (think again of x in an equation — you can substitute any specific number for x, and the equation’s underlying form remains exactly the same). In an analogous way, matter, the Physical Particular, remains consistent as the basic substrate running throughout any physical system — which is exactly why material reductionism (the view that complex physical phenomena can, at least in principle, be fully explained in terms of their smaller material constituents) is a coherent project to pursue in the first place. Matter can certainly be described using a vast range of competing theoretical frameworks over time — Newtonian corpuscles, quantum fields, string-theoretic vibrating strings, and so on — but my goal in this chapter is not to adjudicate between these physical theories about what matter’s ultimate nature turns out to be; that question belongs to physics proper, not to this philosophical Framework for organizing physics. Indeed, some physicists themselves have advanced broadly idealist views, on which the entire physical world is ultimately some kind of emergent mental phenomenon rather than genuinely mind-independent stuff.

That idealist possibility, interestingly, would fit quite comfortably within the Source-Particular Model’s overall structure, though the model by no means requires it. Instead, for the purposes of this chapter, we can simply take “matter” to mean whatever general, indivisible physical unit or units end up occupying physical spacetime, whatever their ultimate nature turns out to be. Yes, matter counts here as an ontological category in its own right — but note carefully that this is a claim only about the category itself, not a specific claim about what matter, in its final physical description, actually consists of. Working out that further, more specific question is squarely the job of physicists, not philosophers, and the philosopher can happily wait for the physicist’s verdict. What the philosopher can say with confidence in advance, however, is that matter’s ultimate nature can, in principle, be discovered by physical science — because otherwise we would be left with genuinely “floating,” unmoored laws of physics and chemistry that have no underlying substance to which they actually apply. And because, on this model, our metaphysical commitments come logically prior to our physical investigations, we can also say with confidence that our physical sciences, properly pursued, should not lead us into outright logical absurdities…

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