Panta chōrei kai ouden menei kai dis es ton auton potamon ouk an embaies.
“Everything changes and nothing remains still … and … you cannot step twice into the same stream.”
This famous phrase by the pre-Socratic philosopher Heraclitus of Ephesus — uttered in the 6th century BCE, marks the historical beginning of the most promising, and yet, as we shall see, somewhat perilous, approach to metaphysics: so-called process philosophy.
As I have written before, I am skeptical of much contemporary metaphysics, the sort of armchair speculation that pretends to discover how the world works by simply thinking about it really hard. That approach, which was in fact started by the pre-Socratics, ended with Descartes’ failure at reconstructing knowledge of the world from the only starting point he could be absolutely sure of: that he existed as a thinking being (cogito, ergo sum; I think, therefore I am). As far as I’m concerned, after that natural science replaced metaphysics as the method by which we find out how things are. It is no coincidence, I think, that Descartes — who was a contemporary of Galileo — thought of himself just as much as a metaphysicians as a natural philosopher, i.e., a scientist.
Then what? Does that mean that metaphysics is dead? Not at all. While the special sciences (physics, chemistry, biology, geology, psychology, etc.) give us bits and pieces of understanding of the cosmos, we still need an overarching way to make sense of all those pieces, to see the full puzzle, so to speak, instead of just its individual components. And we also, constantly, need conceptual clarification of both the results and the methods of science. That, I maintain (together with a number of other contemporary philosophers, for instance Wilfrid Sellars) should be the proper aim of modern metaphysics.
By far the most promising approach to that aim is process metaphysics, which — as German-American philosopher Nicholas Rescher put it — regards “reality not [as] a constellation of things at all, but one of processes. The fundamental ‘stuff’ of the world is not material substance, but volatile flux.” This is distinct from what has been mainstream metaphysics for a long time. Another pre-Socratic, Parmenides, regarded change as entirely illusory. And the most influential metaphysicians of all time, Plato and his student Aristotle, posited that reality is timeless, made of unchanging essences.
One very strong reason to adopt process- rather than object-based metaphysics is because that’s the way science has been leaning for a while. James Ladyman and Don Ross make the most compelling empirically based case for process metaphysics in their masterpiece, Every Thing Must Go, though they call the resulting approach “naturalized metaphysics.” The idea is that physicists are increasingly showing that there are no objects (i.e., particles) at the bottom of reality but rather, at best, fields, and at the most speculative not even those (Ladyman and Ross talk — provocatively — about basic reality being characterized by “relations without relata,” that is points in a field where the points are not really “made” of anything).
Process metaphysics, with its more empirically driven understanding of the world and its reliance on science to keep theoretical speculation from running amok, would be the best and most vital approach to metaphysics available to contemporary philosophers. Except for the fact that it is marred by one very influential, and yet decidedly problematic figure: Alfred Whitehead.
Whitehead is perhaps best known as the co-author, with Bertrand Russell, of the Principia Mathematica, a bold, if ultimately unsuccessful, attempt to put mathematics on solid and self-contained logical foundations. That attempt failed because of two pesky little things known as Gödel’s incompleteness theorems. But that’s another story for another day.
I cannot possibly do justice to Whitehead’s version of process metaphysics (see here for more details and a bibliography), so I’ll limit myself to a partial outline with a focus on the major things I think Whitehead gets right or wrong. Whitehead’s goal was to arrive at what he imagined as a holistic cosmology, that would not be limited to what we mean normally by the science of cosmology, but would also include other forms of human understanding through ethical, aesthetic, and even religious experiences. In an important sense he was right: as much as I am skeptical of the value of religious experience, metaphysics does distinguish itself from science precisely because it is more comprehensive, or “holistic.”
Whitehead was also correct, I think, in regarding metaphysics as a logical framework to articulate discussions about the nature of the world. This means that metaphysics doesn’t pertain directly to facts of nature (that’s the domain of science), but only indirectly, by way of articulating the language and assumptions that make science itself possible. Accordingly — and, again, correctly — Whitehead thought that new scientific discoveries could call some metaphysical positions into questions, and that metaphysicians should respond appropriately. This is precisely what Ladyman and Ross do, and precisely what many modern speculative metaphysicians (like David Chalmers, Nick Bostrom, and anyone who accepts the notion of panpsychism) pretend is not necessary to do.
According to Whitehead what really exists in the universe are “actual entities,” understood as spatiotemporally extended events and processes (which I wouldn’t have called “entities,” given that the term is rather ambiguous). Whitehead maintains that all actual entities are “occasions of experience.” He distinguishes four levels of these occasions: basic physical processes, occasions involving inanimate matter, occasions involving living organisms, and occasions involving human-type subjective experiences. But I don’t think there is any reason to retain this kind of obfuscatory language, which reminds me of the ancient Stoics’ distinction between levels of pneuma (breath), the basic substance that permeates the universe. From a scientific perspective, all these levels are part of a continuum, possibly characterized by emergent properties, and we should — whenever possible — adopt the more precise language of science.
Unfortunately, Whitehead makes one gigantic exception to his rule that all actual entities are occasions of experience: god. The deity is understood by Whitehead as being both temporal and atemporal, leading to something called process theology. Setting aside that this raises the possibility of logical contradiction, I just don’t think there is any reason at all — and certainly no empirically, science informed reason — to think that any gods exist, so process metaphysics in the hands of Whitehead here takes a decidedly wrong turn.
(No, I’m not going to go through the standard arguments for why it isn’t necessary to believe in gods. It has been done ad nauseam before. I will only point out that I am an a-theist in the etymological sense of the word: I lack positive belief in gods, which is not the same as saying that I know for a fact that there are no gods. That remains a logical possibility. But reliance on mere logical possibilities is precisely what we are trying to get metaphysics away from!)
Where I (partially) rejoin Whitehead is in the notion that there is no mind-body dualism in the world. He considers mind to be an abstraction from an occasion of experience that is also characterized by a material aspect. A rather unnecessarily fancy way to say that “minding” (I prefer the verb, which indicates a process, rather than an object) is what the brain does, given certain boundary conditions (like, being alive and biologically functional).
Unfortunately, Whitehead’s non-dualism leads him to shaky territory. Although he wasn’t really an idealist, his views are awfully close to the above mentioned notion of panpsychism (or panexperientialism). This idea comes in a number of forms, but basically says that mind (or consciousness) is a fundamental aspect of reality. An idea for which there is not a shred of empirical evidence, and that therefore brings back process metaphysics into the sort of speculative metaphysics I maintain died with Descartes. (For much more on why I’m skeptical of panpsychism, see this in-depth exchange with one of panpsychism’s leading proponents.)
Why is process philosophy called “process”? Because every occasion of experience (again, this just means any spatiotemporally extended event or process) is potentially causative of others such occasions, and is itself the causal consequence of previous occasions of experience. A bit of a convoluted way to say that Whitehead accepts the notion of universal causality (which, incidentally, is also a Stoic concept).
Whitehead explains the existence of what appear to be Aristotelian substances, i.e., enduring physical objects, as the nexus of temporally overlapping occasions of experiences. These enduring “objects” are characterized by an earliest and a last temporal member (when the object comes into existence and when it ceases to exist). The terminology could and should be updated, but it is in sync with contemporary notions from fundamental physics.
Whitehead also makes sense of what he calls “eternal objects,” for instance, numbers. They are abstractions, conceptual entities that refer to more than one single actual entity. Although this smells a bit of mathematical Platonism, Whitehead himself seems to step back from that metaphysically controversial notion, as he additionally adopted an ontological principle according to which abstractions are “real” only in the sense that their existence is derived from actual entities in the world (i.e., us), similar to the Stoic distinction between existence and subsistence, both of which are elements of reality (see here).
Part of the problem I find with Whitehead’s philosophy is that it can be described as complex, subtle and nuanced. Or — depending on your degree of sympathy for his ideas — as unnecessarily obfuscatory, at least almost a century after it was originally articulated. More broadly, it seems to me that too many philosophers attracted to process metaphysics are stuck in the early 20th century, when Whitehead was active, and do not take into sufficient account the development of Ladyman and Ross-style naturalistic metaphysics.
So here is my suggestion moving forward:
I. By all means, let’s finally do away with an ontology of universal substances and static objects, embracing instead the Heraclitean dictum: panta rhei, everything changes.
II. Let’s also finally discard speculative metaphysics (sometimes referred to as “first philosophy”) a la Chalmers et al. and agree that if we are concerned with discovering facts about the world then science is the way to go. May Descartes rest in peace.
III. Let us acknowledge, however, that science by itself isn’t capable of producing the overarching understanding of the puzzle of reality that we are after. Naturalized metaphysics a la Wilfred-Ladyman-Ross is the way to go.
IV. Finally, let us do away with non-scientific or even anti-scientific notions, such as gods and panpsychism, with the proviso of course that they may reenter the fray if and when we get decent empirical reasons to reconsider them. I wouldn’t hold my breadth, though.