Just Make Sense: Metaphysics, Metametaphysics, Emergence, Grounding and Indeterminacy

Interview by Richard Marshall

'How to approach a given metametaphysical question will depend on the question, but my overall strategy is just to proceed in a way that makes sense. For example, questions about methodological standards in metaphysics should be approached through the lens of epistemology, not language.As regards the methodological question, I do see reason for optimism. To start, there’s been tons of great work on philosophical methodology done in the past decades—we’re getting clearer about the role of inference to the best explanation and the associated abductive principles, about logic(s), conceiving, intuitions, and other factors relevant to assessing metaphysical theories. Moreover, metaphysicians aren’t really that far apart, methodologically speaking.'

'One of the emergent themes of my work—I didn’t plan this, the pattern just kept manifesting—is that certain assumptions acting as operative constraints on metaphysical theorizing are curiously undermotivated. A semantic approach to metametaphysical questions is one—why take this tack if you aren’t Carnap (or even if you are)? Another is Hume’s Dictum. This view makes some sense if you’re Hume, and the content of ideas ultimately originates in sense impressions—sure, the superficial appearance of bread might not produce the superficial appearance of nourishing. But those taking Hume’s Dictum as foundational don’t accept Hume’s idea-istic empiricism, so why believe the thesis it generates?'

'The introduction of Grounding is a case-in-point of another barrier to philosophical progress, associated with what I’ve called ‘intra-disciplinary siloing,’ where people working on broadly the same subject matter from within different frameworks fail to be familiar with each others’ work, leading to the lack of appreciation of needed distinctions, the reinventing of wheels, the creation of spandrel questions, and other forms of wasted effort.'

'The notion of metaphysical emergence isn’t specifically tied to physics. To be sure, the notion of metaphysical emergence is initially inspired by attention to special science entities, which appear to cotemporally (i.e., synchronically but not necessarily instantaneously) depend on (typically massively complex) combinations of physical goings-on, but which also appear to be to some extent ontologically and causally autonomous—that is, to be distinct from, and distinctively efficacious as compared to, lower-level physical goings-on. But the general notion of metaphysical emergence as coupling dependence and autonomy—as between, e.g., mental states and brain (and ultimately fundamental physical) states—could in-principle apply to other purported dependence bases.'

'I do think that there is genuine metaphysical indeterminacy (MI), and quite a lot of it! Many goings-on seem to be indeterminate: the boundaries of objects, open future claims, certain properties of systems on various interpretations of quantum mechanics. On the face of it, the indeterminacy at issue in these cases is not semantic, much less epistemic—it’s not plausible that the seeming indeterminacy of a cloud reflects our not having decided exactly which molecules are the proper referent of a given use of ‘cloud,’ or that Mount Everest does have a perfectly precise boundary, but we just don’t know which one it is; and in the cases of open future and quantum indeterminacy, semantic and epistemic spins are even less appropriate.'

Jessica Wilson is a philosopher of metaphysics and epistemology. Here she discusses gender and philosophy, why anyone would be pessimistic about metaphysics in a post-positivist age, optimism, how dogmas hold back philosophical enquiries, metaphysical grounding, the 'Fundamentality First' view, metaphysical emergence, panpsychism, coupling dependence and autonomy, causal autonomy and metaphysical emergence and Kim's dilemma, weak and strong emergence, why strong emergence makes sense, minds and freewill as parade cases for strong emergence, and why she thinks there is quite a bit of metaphysical indeterminacy and vagueness.

3:16: What made you become a philosopher? And as a philosopher who is also a woman in the academy, have you faced difficulties because of your gender?

Jessica Wilson: It took me a while to find philosophy! I went to art school in Baltimore, studied physics at the University of Maryland, and ended up with a degree in math from UCSD, but these studies were more like cultural experiences—none of the modes of investigation crossed with the subject matter completely resonated with me. I was living in Boulder working as a programmer when I became deadly bored and decided that I had to go back to school, though I wasn’t sure in what—something involving reading, thinking, writing. I was paging through the CU Boulder course catalog and came across the philosophy courses. Finding out that metaphysics, epistemology, philosophy of mind were live disciplines, going beyond the ‘history of ideas’ presentations of ancient and political philosophy in my general studies courses, was a real ‘Eureka!’ moment for me. I started taking classes and sure enough, I had finally found my true metier.

As for the gender issue, I’ve been fortunate—my being a woman hasn’t posed any serious difficulties for me in academia. I’ve had very supportive and congenial intellectual environments and relationships throughout my career, and there has been good pickup of my work, with all that positively entails.That said, implicit bias is an ongoing problem for women in philosophy, and I’ve experienced my share of that. This shows up mainly in citation failures (I had to fight for years for people to stop referring to the subset-of-powers approach to realization I advanced in 1999 as ‘Shoemaker’s Subset Theory’) and in papers of mine that end up being highly regarded and influential (e.g., ‘No Work for a Theory of Grounding’) getting rejected from journals like Philosophical Review for no good reason. In re publishing it’s worth noting that once one achieves a certain degree of prominence and especially if one is pushing distinctive views, there’s really no such thing as blind refereeing; and since implicit bias works in both directions (negative for some, positive for others) the predictable upshot is that, irritatingly, it becomes easier for established men and harder for established women to publish in top journals. Exacerbating the problem is that, as I discuss in ‘Three Barriers to Philosophical Progress,’ the current lack of determinate methodological standards in philosophy renders our discipline especially subject to implicit bias, as a case-in-point of the empirical fact that bias flourishes when assessment is flexible.

There’s no quick fix here, though journal and other quotas might help. The usual dismissive response is that quotas would somehow ‘taint’ the venue or the work, but since implicit bias works in both directions the impact of quotas for women would foreseeably improve, not decrease, overall quality. Of course people would need to be educated about this. Anyway, in the absence of concrete action along these lines, we women in philosophy have to, as my grandmother would say, “just rise above it.”

3:16: You think about metaphysics, and metametaphysics! Let’s start with the latter. One of the issues is whether there’s a role for metaphysics anymore. You ask at one point—why be pessimistic about metaphysics in a post-positivist age? You note that a lot of philosophers are, however. So what is this pessimism about? Is it Carnap’s fault?

JW: The lack of determinate methodological standards also enters in here. Carnap’s pessimism is usually expressed as a semantic thesis, according to which metaphysical claims are meaningless, but his motivation for this thesis was that metaphysicians don’t share standards sufficient unto confirming or disconfirming their claims. The epistemological concern is a live one, and doesn’t hinge on Carnap’s idiosynchratic views about meaning; moreover, it pretty obviously applies to any area of philosophy. In any case if this concern is going to inspire contemporary pessimism about metaphysics, then we need to assess, first, what the prospects are for metaphysicians’ eventually converging on determinate standards, and second, whether progress can be made even independent of such convergence.

Interestingly, however, contemporary pessimists don’t engage with the epistemological concern. They take some variation on Carnap’s semantic thesis as a starting point, and go on to conduct their metametaphysical investigations through the lens of language. The focus then becomes, e.g., whether the presumed fact that metaphysical disputes are merely verbal reflects disputants’ speaking different languages, or whether the presumed fact that metaphysical claims are semantically indeterminate reflects the use of a defectively indeterminate quantifier or rather the availability of multiple equally good though incompatible quantifiers. Even contemporary optimists often endorse the semantic approach; as Sider put it, “the central question of metaontology is that of whether there are many equally good quantifier meanings, or whether there is a single best quantifier meaning.”

My own view (which I expand on in my critical notice of the Metametaphysics anthology) is that all this introduces an unhelpful layer of linguistic complexity, and distracts from the main issue, which is epistemic, not semantic.

3:16: So what’s the optimistic alternative to treating metametaphysical questions in semantic or quantificational terms? Are you optimistic?

JW: How to approach a given metametaphysical question will depend on the question, but my overall strategy is just to proceed in a way that makes sense. For example, questions about methodological standards in metaphysics should be approached through the lens of epistemology, not language.

As regards the methodological question, I do see reason for optimism. To start, there’s been tons of great work on philosophical methodology done in the past decades—we’re getting clearer about the role of inference to the best explanation and the associated abductive principles, about logic(s), conceiving, intuitions, and other factors relevant to assessing metaphysical theories. Moreover, metaphysicians aren’t really that far apart, methodologically speaking. Everyone agrees that kludginess is a cost, that plausibility is a virtue, that ontological parsimony as regards fundamentals is desirable other things being equal, that metaphysical theories should be consonant with our best scientific theories, and so on. The disagreement tends to lie not in the theoretical desiderata but in how these desiderata are weighted, and also—crucially—in which further metaphysical theses are taken as methodologically foundational. Should parsimony be weighted more heavily than plausibility, or compatibility with intuitions? Should Hume’s Dictum, according to which there are no necessary connections between wholly distinct existences, be taken as a constraint on metaphysical theorizing? Some go one way, some go another, but of course that isn’t the end of the matter. After all, philosophers can consider what motivations exist for a given weighting or foundational assumption and what impact adopting that approach has on whether and how the data and the desiderata can be accommodated. Finally, even in the absence of consensus on these scores, metaphysicians can and are making progress in determining what would be true given certain methodological and theoretical assumptions, as a kind of conditional investigation into our options for understanding the nature of reality. This may not eventuate soon, or ever, in metaphysical truth with a capital ‘T,’ but it’s still hugely informative.

Another important metametaphysical question concerns what metaphysics is, and how it does or does not differ from other endeavors. This is also a properly metaphysical question! My preferred understanding of metaphysics is also optimistic, and stands opposed to the view, endorsed by some scientists and philosophers, that there isn’t any distinctive role for metaphysics—that ordinary experience, science, or conceptual analysis are already answering any first-order metaphysical questions we might have. On what I call the ‘embedded view’ (sketched in ‘The Question of Metaphysics’), the distinctive role for metaphysics lies in theorizing about the notions and concepts operative in other disciplines and in ordinary experience, at a characteristic level of generality and with an eye to systematic integration. The embedded view is opposed not just to versions of pessimism according to which metaphysics has nothing interesting to do but also to the ‘hands-off’ view which some optimists endorse, according to which metaphysics is legitimate on its own turf but has no right to meddle in the claims of other disciplines. As I see it, figuring out reality—scientific, mathematical, social—is a shared endeavor, not something we metaphysicians do by ourselves in a special room, much less via a proprietary language.

3:16: You discuss three dogmas in metaphysics. Does dogma hold philosophy back? This seems to take us back to the initial thing we were discussing—is, for example, a Carnapian semantic metametaphysical dogma one of the things holding philosophy back?

JW: One of the emergent themes of my work—I didn’t plan this, the pattern just kept manifesting—is that certain assumptions acting as operative constraints on metaphysical theorizing are curiously undermotivated. A semantic approach to metametaphysical questions is one—why take this tack if you aren’t Carnap (or even if you are)? Another is Hume’s Dictum. This view makes some sense if you’re Hume, and the content of ideas ultimately originates in sense impressions—sure, the superficial appearance of bread might not produce the superficial appearance of nourishing. But those taking Hume’s Dictum as foundational don’t accept Hume’s idea-istic empiricism, so why believe the thesis it generates? Similarly for a classical mereological approach to material object composition—why believe this if you aren’t a nominalist (one eschewing properties and relations) in need of an ontologically lightweight means of combining micro-objects to get macro-objects? Contemporary proponents typically don’t offer new motivations for these views, but when they do, the motivations don’t withstand scrutiny—or so I’ve frequently argued. But then adherance to these principles comes down to what I’ve called premature dogmatism, driven primarily by sociological considerations—certain (typically prominent) others endorse it, so I can or should too—rather than philosophical ones.

Does premature dogmatism impede philosophical progress? Yes. To start, it discourages other potentially more fruitful lines of investigation. That’s bad in itself, of course, and even indirectly injures dogmatic positions, since positive confirmation of these positions requires comparing them to their best competitors. Dogmatism also encourages what I’ve called ‘ineffective overachievement,’ where good minds expend great effort in trying to salvage implausible, unmotivated views. Imagine if everyone had devoted their lives to propping up Ptolemy rather than shifting to the more natural Copernican view. As I previously put it, “it has not been good for philosophical progress that so many philosophers have spent decades laboring in the imaginary Legoland of Hume’s Dictum.” (I’m proud of that one since it was made into an awesome Monstrous Metaphysical Meme!)

Of course, that effort isn’t completely wasted, since along lines of the kind of conditional results mentioned above, it adds to the stock of knowledge about our metaphysical options. And it’s not as if competing frameworks are disallowed in this and other cases of premature dogmatism—usually some competing frameworks are also on the table. It’s a matter of emphasis. I’d like to see philosophers be more self-aware and explicit about the speculative and in some cases under-motivated status of their foundational presuppositions. Stop pronouncing, y’all! If you want to explore reality as constrained by Hume’s Dictum, fine, but don’t propagate the fiction that this is the only or obviously correct way to go.

3:16: Speaking of contemporary dogmas, you’ve recently engaged with the debate about metaphysical grounding—the ‘big G!’ What is this and why do some philosophers think we need it? It is an Aristotlelian notion, isn’t it?

JW: As it happens, Grounding is not really an Aristotelian notion. Let me explain. The term ‘grounding’ used to be used as a schematic term, ranging over specific metaphysical dependence relations; hence a physicalist might say ‘I believe that everything is grounded, one way or another, in physical goings-on,’ leaving open which dependence relation(s) might be operative in different cases. The expression was since co-opted—hence I ‘big-G’ it—as a purported primitive generic relation or notion of metaphysical dependence, supposed to be operative in any and all cases of such dependence, and supposed to either be or to back metaphysical explanations of the sort associated with ‘in virtue of’ locutions (as in ‘the table exists in virtue of the aggregate of atoms’s existing,’ ‘the rose is red in virtue of its being scarlet,’ ‘the conjunction is true in virtue of each of its conjuncts’s being true’). The original motivation for Grounding was as follows: since Quine, metaphysicians have been concerned mainly with what exists, ignoring metaphysical dependence questions except as deflationarily treated in terms of supervenience (merely modal connection) or conceptual entailment; but for various reasons, supervenience and conceptual entailment aren’t up to the task of characterizing metaphysical dependence; so we should posit primitive Grounding as a substantive metaphysical dependence relation or notion, stipulated to have the formal features of a hyperintensional partial order. Grounding is sometimes glossed as an Aristotelian notion, but it’s not, except in the sense that Aristotle (like many other philosophers throughout history) would have agreed that there are substantive metaphysical dependence relations; he never posited a generic, much less primitive, form of such dependence.

The introduction of Grounding is a case-in-point of another barrier to philosophical progress, associated with what I’ve called ‘intra-disciplinary siloing,’ where people working on broadly the same subject matter from within different frameworks fail to be familiar with each others’ work, leading to the lack of appreciation of needed distinctions, the reinventing of wheels, the creation of spandrel questions, and other forms of wasted effort.

In particular, the original motivation for Grounding would be obviously enthymematic to anyone familiar with work in the metaphysics of science and mind, where it has been recognized since the 1970s that modal and conceptual/representational approaches to metaphysical dependence were unsatisfactory. In the ensuing decades, philosophers working in those areas (and others) generated a large literature exploring what I call small-‘g’ grounding relations, including type and token identity, functional and other forms of realization (including subset-of-powers realization), the determinable-determinate relation, the part-whole relation, constitutive mechanisms, and so on, which against backdrop assumptions about what is fundamental (typically, in these contexts, the physical goings-on), serve as properly metaphysical dependence relations. It’s hard not to conclude that the original proponents of Grounding were simply unfamiliar with all this work. That doesn’t make any less tiresome the ensuing literature on Grounding, which mainly consists in rehearsing counterexamples to the supposed formal features, pondering spandrel questions (What Grounds Grounding? What Grounds that the Grounds Ground Grounding?) generated by the failure of this stipulated primitive to actually close explanatory gaps, and offering Grounding-based ‘formulations’ of views (naturalism, physicalism) which are generic variations on the traditional schematic starting points of more substantive formulations.

It would have been dialectically more apropos if the original line had rather been: look, there are a bunch of specific metaphysical dependence relations out there. What case might there be for there being a generic dependence relation or notion operative in all these cases? Existing literature in hand, one would then be in position to avoid certain clear dead ends. Are the specific metaphysical dependence relations formally unified? No, so stipulating that all such relations have the structure of a partial order isn’t an option. Even if they are unified in some respect, does it follow that an ontological posit corresponds to said unity? No, since (as debates over the status of determinables illustrate), in other contexts the default presumption is rather that generic notions should be given a schematic or disjunctive treatment in terms of the more specific notions, especially when we can’t do without the latter, as is the case with the small-‘g’ relations.

Even if a case can be made for a generic posit here, does it follow that the posit is primitive? No, since in other contexts generics, even if irreducible, are taken to be metaphysically dependent on the more specific notions. Methodologically, what use would a primitive notion of metaphysical dependence be? Not much, since we metaphysicians don’t have access to which direction this primitive is pointing in a given case. Supposing we go ahead and posit this primitive, should it count as either being or backing ‘metaphysical explanation?’ No, since a primitive notion of metaphysical dependence isn’t capable of closing explanatory gaps, and indeed introduces new ones (What Grounds Grounding? Why does Grounding point in one direction rather than another in a given case?). Plus, why assume that metaphysical dependence necessarily brings explanation in its wake? Certainly the majority of physicalists, who suppose that explanatory gaps (e.g., between qualitative mental states and physical states) are compatible with metaphysical dependence, do not assume this. And so on.

Here again, the effort isn’t entirely wasted. Beyond the original spurious motivation for Grounding, other motivations have been brought forward, including its potential usefulness in providing a reductive account of fundamentality, according to which what makes it the case that some goings-on are fundamental is that they are individually unGrounded. This is worth considering, and raises to salience that there is a deep if non-uniform connection between fundamentality and metaphysical dependence. That said, a package deal combining Grounding with an analysis of fundamentality as the unGrounded has clear problems, including that it rules out of court certain seemingly live accounts of fundamental structure (as involving, e.g., a self-dependent God, interdependent quarks, or fundamental yet partly dependent—Strongly emergent—mental states). So I don’t see any good motivation for Grounding here, either. Of course, there’s more that proponents of Grounding can say. At the end of the day the question is whether there are better conceptions of fundamentality and metaphysical dependence on offer.

3:16: What are your preferred alternative conceptions of fundamentality and metaphysical dependence?

JW: My preferred package deal—what I call the ‘Fundamentality First’ view—is one coupling a primitivist account of what makes it the case that some goings-on are fundamental with a pluralist account of metaphysical dependence as involving diverse small-‘g’ relations. A primitivist account of fundamentality has certain advantages, including that it doesn’t antecedently rule out of court the aforementioned views, and it naturally encodes certain heuristic understandings of the fundamental goings-on as collective starting points for all else. And a pluralist account of metaphysical dependence properly accommodates the full range of existing, diverse ways in which some goings-on can metaphysically depend on some others.

This package deal also nicely accommodates the fact that some relations serving as metaphysical dependence relations—e.g., the part-whole relation—don’t carry their direction of priority on their sleeve. For example, Atomists and Monists agree that the Cosmos and atoms are related as whole to parts, but Atomists think that atomic parts are prior to the Cosmic whole, whereas Monists think that the Cosmic whole is prior to its atomic parts. Moreover, their disagreement is not over which direction parthood should always point: as Schaffer observes, the Monist can allow that the legs of a table are prior to the table, and the Atomist can allow that tables are prior to their legs. If the small-‘g’ relations themselves don’t determine what direction of priority is associated with a given instance of the relation, what does? On my account, this proceeds in three steps. First, which goings-on are fundamental is primitively specified. Second, this primitive specification fixes the direction of priority between instances of small-‘g’ relations holding between the fundamenta and the non-fundamenta. For example, if the Cosmos is the only fundamental entity, then proper parts of the Cosmos are non-fundamental, whereas if the atoms are the only fundamental entities, then mereological fusions of the atoms (including the Cosmos) are non-fundamental. Third, priority relations between non-fundamenta, where these exist, are then a function of the natures of the non-fundamenta (as small-‘g’ related to the fundamenta) and of what small-‘g’ relations hold between the non-fundamenta at issue. Note that there’s no supposition here that instances of a given small-‘g’ relation must always point in the same direction—for example, a Monist can allow that parts of a table are prior to the table as a whole.

To be sure, a proponent of primitive Grounding could insist that it is this posit that fixes the direction of priority of instances of the small-‘g’ relations: sometimes Grounding swoops in and makes it the case that some parts are prior to their fusion, and other times Grounding swoops in and makes it the case that the fusion is prior to its parts. But it’s hard to see how metaphysical investigation into what depends on what is supposed to proceed, on such a view.By way of contrast, the Fundamentality First view codifies how metaphysical investigations have usually proceeded throughout history. Again, bracketing iterations prior to reflective equilibrium, there’s basically a three-step process at work. First, one assumes, as a speculative, antagonistic, or working hypothesis, that some goings-on are fundamental (or serve as fundamental in context—if, for example, what’s at issue is whether social practices are prior to social categories). Second, one considers whether and how goings-on not obviously part of the supposed fundamental base might small-‘g’ stand to the supposed fundamenta. If one can’t make sense of how some goings-on not initially in the fundamental base metaphysically depend, one way or another, on goings-on in the base, one faces certain choices, including whether to eliminate the purported non-fundamenta, or rather to add them to the fundamental base. Third, with relevant non-fundamenta in hand, one considers whether and how these might depend on each other, given facts about how they small-‘g’ stand to the fundamenta and to each other. I’m now writing a book— Fundamentality and Metaphysical Dependence —motivating and defending my preferred package deal.

3:16: Would you be writing this book if you hadn’t been irritated into doing so by the advent of Grounding?

JW: Probably not!

3:16: Speaking of books, your book Metaphysical Emergence has just come out. Your arguments around emergence assume that the little things of physics somehow make up and provide a basis for the big things around us, like people, tables, planets, minds and so on. But substance dualists and panpsychists find that too incredible to believe and deny this dependence. It seems that all three positions face big challenges when you try and understand how the metaphysics of each must work, though I sense that most people just assume that everything is ultimately physical. How did you decide between the positions, and are you ever tempted by these alternatives?

JW: Actually, the notion of metaphysical emergence isn’t specifically tied to physics. To be sure, the notion of metaphysical emergence is initially inspired by attention to special science entities, which appear to cotemporally (i.e., synchronically but not necessarily instantaneously) depend on (typically massively complex) combinations of physical goings-on, but which also appear to be to some extent ontologically and causally autonomous—that is, to be distinct from, and distinctively efficacious as compared to, lower-level physical goings-on. But the general notion of metaphysical emergence as coupling dependence and autonomy—as between, e.g., mental states and brain (and ultimately fundamental physical) states—could in-principle apply to other purported dependence bases. It’s also worth noting that the general notion of metaphysical emergence doesn’t build in that the base goings-on involve (massive combinations of) ‘little bits’—maybe the base entities are fields or whatever. So my official schemas for metaphysical emergence don’t build in that the dependence base entities are physical or particulate. A panpsychist could allow, for example, that the conscious mentality of humans metaphysically emerges from states of conscious fields!

That said, in my book I usually provisionally assume that the dependence base goings-on are physical, where the physical goings-on are, roughly (see ‘On Characterizing the Physical’ for details), those falling under the rubric of fundamental physics (including aggregative or physical-law-based combinations of whatever the individual physical entities and features turn out to be) with the proviso that individual fundamental physical goings-on do not have or bestow mentality, contra the panpsychist conception of the basic constituents of matter. (Note, by the way, that to deny that individual physical entities are in any sense conscious is compatible with their not being completely qualitatively etiolated—perhaps particles feel forces in some sense.) In the first instance I do this to connect with the literature. One of the key questions I aim to answer is whether there are one or more viable (coherent, intelligible, naturalistically acceptable) conceptions of metaphysical emergence, and concerns with such emergence typically take for granted that the base goings-on at issue are physical. I also do this since another question I aim to answer in my book is whether there actually is any metaphysical emergence, and that the base goings-on are physical is a plausible default assumption, especially given that the usually stated motivations for substance dualism and panpsychism, as in James van Cleve’s classic ‘Mind Dust or Magic? Panpsychism vs. Emergence,’ are the purported failures of emergentist views on which this assumption is in place. I end up arguing for positive answers to both questions. I don’t really argue against substance dualism or panpsychism directly—I just undercut the stated need for such views.

If I had to choose one of these alternatives, though, I’d go for panpsychism. I kind of like the idea that the universe is alive and aware all the way down.

3:16: You say that autonomy—both ontological and causal—is a key element for the special sciences. What is this and what motivates this idea? Does it have degrees – and shouldn’t that worry us – might that not be our own epistemic ignorance talking rather than metaphysics? How can things be actually caused but only to a degree?

JW: Your first question gets at the prima facie reasons for thinking that there is metaphysical emergence, coupling dependence and autonomy. I see ontological autonomy—distinctness—as motivated by the distinctive taxonomies of the special sciences. And I see causal autonomy—distinctive efficacy—as motivated by distinctive special science laws. I also argue that ordinary experience supports the ontological and causal autonomy of macrophenomena. As for whether the autonomy at issue comes in degrees—I suppose it depends on how exactly we are thinking about the notions of autonomy at issue. Certainly special science entities and features don’t appear to be completely autonomous from the goings-on upon which they cotemporally depend. In the book I moreover characterize the dependence at issue here as ‘material,’ as a comparatively generic way of encoding the emergentist assumption that the dependent goings-on are not new substances (such that, given a physical dependence base, the only substance is physical substance). But whether it follows that either ontological or causal autonomy comes in degrees is questionable. I do sometimes say that emergents are ‘in some sense’ or ‘to some extent’ ontologically or causally autonomous, but that’s just to flag that the operative notions of distinctness and distinctive efficacy need to be filled in, not to suggest that emergents are not as real as, or cause effects to a lesser degree than, their physical bases.

You are right, though, that there’s a deflationary strand of thought according to which the appearances of special scientific autonomy are given an epistemic spin. How one wants to respond to deflationary suggestions will depend on their motivations. If the idea is simply that it would be ontologically more parsimonious if only a single level of massively complex physical goings-on existed, then that on its own doesn’t count very heavily for me. My own methodological preferences—and I try to be explicit about this in the book—are weighted in favour of straightforward, non-revisionary accommodation of the appearances, compatibility with a broad range of theories and practices, systematicity, and so on. Deflationary views do quite poorly along these other dimensions—or so I argue. I treat this as well as many other challenges to metaphysical emergence in the book.

3:16: So how does the notion of causal autonomy fit with metaphysical emergence? It might seem to some, like Jaegwon Kim!, that if there really is causal autonomy—if a special-scientific thing has causal autonomy, and so does the physical thing upon which it depends—then there’s too much causal autonomy going on, and something’s got to give! And once might even be concerned that special scientific causal autonomy would undercut the assumption of substance monism. Why isn’t this right?

JW: Yes, perhaps the most immediately pressing concern for metaphysical emergence, and more generally for the posit of higher-level goings-on, is associated with Kim’s exclusion problem. Focusing on special science features, the concern is that there is no way to reconcile the assumptions that special science features exist, are efficacious, and are dependent on yet distinct from physical features, with the common suppositions that the physical is causally closed (every physical effect has a purely physical cause), and that effects are not systematically caused twice over. Some responses to the problem are associated with non-emergentist conceptions of natural reality: rejecting the reality, distinctness, efficacy, or dependence of special science features corresponds to eliminativism, reductive physicalism, epiphenomenalism, or substance dualism (or panpsychism), respectively. Two responses do accommodate emergence, however: Strong emergence rejects physical causal closure, rather maintaining that some physical effects do not have purely physical causes, and Weak emergence rejects non-overdetermination, rather maintaining that, even if the effects of Weakly emergent features are also brought about by base features, the associated overdetermination is not problematic.

The Strong and Weak emergentist responses to Kim’s dilemma provide a basis for a special science feature’s being ontologically and causally autonomous without introducing anything like substance dualism. At the heart of the Strong emergentist’s response (as endorsed by, e.g., the British Emergentist C. D. Broad) is that a Strongly emergent feature is causally autonomous in having a fundamentally novel power—a power that is just as fundamental as the powers of fundamental physical features. And at the heart of the Weak emergentist’s response (as operative, I argue, in diverse forms of non-reductive physicalism) is that a Weakly emergent feature is causally autonomous not in having of a fundamentally novel power—that would falsify physicalism—but rather in having a distinctive power profile, and more specifically in having a proper subset of the powers of its dependence base feature. Neither of these approaches to causal autonomy invokes a new substance. It’s also worth distinguishing new objects or entities from new substances. Emergentists are typically happy to allow that an emergent feature might bring an emergent object in its wake, but that’s a far cry from allowing that emergence gives rise to novel substances of the sort at issue in, e.g., Cartesian dualism. For example, if substances are supposed to be the sort of things that can exist independently, then emergent objects are not substances.

3:16: What, more precisely, is the distinction between Weak and Strong emergence? What kinds of things would be Weak, which Strong, and would only the Strongly emergent things count as real, and all the rest be anti-realist?

JW: Taking my cue from the emergentist responses to Kim’s dilemma, I offer schematic formulations of Weak and Strong emergence in powers-based terms. In each case there’s a dependence condition and an autonomy condition. In terms of features, the dependence condition in both cases simply requires that, on any given occasion, an emergent feature cotemporally materially depends on some base feature, where this encodes substance monism along with the supposition that emergent features supervene with at least nomological necessity on base features. For a Strongly emergent feature, the autonomy condition requires that the feature have, on some occasion, a token power that its dependence base feature doesn’t have on that occasion (or has only due to its being a necessary precondition for the occurrence of the Strongly emergent feature). For a Weakly emergent feature, the autonomy condition requires that the feature have, on any occasion, a proper subset of the token powers of its dependence base feature on that occasion. Basically, an emergent can either have more powers (Strong) or fewer powers (Weak) than its dependence base feature.

As I see it, features satisfying the conditions on either Strong or Weak emergence are equally real, and are each as real as their base features. By Leibniz’s Law, each is distinct from its base feature(s); moreover, each is distinctively efficacious as compared to its base feature(s). This last is easy to see for Strongly emergent features. For Weakly emergent features, distinctive efficacy is gained not by having a distinctive power, but rather by having a distinctive power profile, which tracks difference-making considerations (if my thirst had been differently realized, I would still have reached for the Fresca) and abstract levels of causal grain of the sort associated with special science taxonomies and laws.

As for what goings-on are Weakly or rather Strongly emergent: in the book I consider, in dedicated chapters, what cases there are for complex systems, ordinary objects, qualitative consciousness, and free will being either Weakly or Strongly emergent. While most existing cases for these being even Weakly emergent are incomplete, cases can be made that each is at least Weakly emergent. In some cases, the Strong emergence of the phenomenon remains an open if unlikely empirical possibility. And I argue that free will is actually Strongly emergent.

3:16: Why do you think Strong emergence makes sense—are you saying that any Strongly emergent features or powers don’t collapse into their lower-level?

JW: I do think it makes sense, though you are right that there is a challenge here. As above, on my view Strongly emergent phenomena have fundamentally novel causal powers—powers their dependence base phenomena don’t have. Some argue, however, that this conception doesn’t make sense, since dependence base goings-on will inherit any such purportedly novel powers, as per what Elanor Taylor evocatively calls ‘the collapse problem.’

There are various ways to block collapse, as Umut Baysan and I discuss in ‘Must Strong Emergence Collapse?’ One way is to distinguish between the direct and indirect having of a power: Strong emergents have their powers directly, whereas their physical bases only have the powers indirectly, in virtue of being necessary preconditions for the Strong emergent which more directly has the power. Another way is to take novel powers to generate novel objects, blocking attribution of the novel power to the base-level goings-on; this is Umut’s favoured response. My preferred response proceeds via the plausible theses that powers are grounded (to speak schematically) in fundamental interactions, and that the fundamentally novel powers of Strong emergents are associated with non-physical fundamental interactions. These theses in hand, one can relativize Strong emergence to sets of fundamental interactions: if there is Strong emergence, then relative to just the fundamental physical interactions, some dependent goings-on have fundamentally novel powers, as desired.

3:16: Why do you think minds and free will are parade cases for Strong emergence?

JW: Well, it is admittedly hard to understand how qualitative consciousness and genuinely free choice might be completely metaphysically dependent on even massively complex lower-level physical goings-on. There’s a persistent explanatory gap in these cases—first, between the non-qualitative and qualitative; second, between the law-governed and the anomolous. Still, it remains to say why a given epistemic gap should be indicative of the kind of fundamental novelty at issue in Strong emergence.

The British Emergentists—the original Strong emergentists—had pretty good reason for thinking that certain explanatory gaps, involving ‘in principle’ failures of deducibility or predictability, were indicative of fundamental novelty. At the time it was commonly thought that causation involved fundamental forces (e.g., gravity, electromagnetism) operating in accord with linear composition laws. So given that no new fundamental forces were operating, one should be able to predict the behaviour of a composite system as a linear combination of the forces associated with its composing parts. Conversely, failures of features or behaviors of composite systems to be subject to linear analysis were reasonably thought to indicate that some additional fundamental force—a force not operative at less complex levels of natural reality—was now in operation.

The appreciation of nonlinear complex systems clearly not involving any novel fundamental interactions undercut that sort of inference. But the temptation remains to give explanatory gaps a metaphysical spin. This is especially true in the literature on qualitative features of consciousness, as in the case of Nagel’s bat, Jackson’s Mary, and Chalmers’s zombie. I consider these routes to rejecting physicalism and (along with certain other assumptions) endorsing Strong emergence, and argue that they don’t succeed

.Nagel and Jackson-style considerations fail, in my view, since they rely on an impoverished conception of the physical goings-on as somehow objective and non-qualitative. For example, Jackson’s knowledge argument relies on the premise that a scientist could have complete physical knowledge about human colour science from within the confines of a black-and-white room; but if physical knowledge is knowledge of physical goings-on, and if (as the physicalist believes) physical goings-on are either identical to or realize experiences of colour, a physicalist can simply reject this premise, rather maintaining that complete physical knowledge would require familiarity with states of affairs associated with human colour experiences. As I put it in my book, rather than stand opposed to the intuitively compelling take on Mary’s response to seeing a ripe tomato—‘so this is what it is like to see red!’—according to which she does come to know a new fact after leaving her room, the physicalist can rather simply agree that Mary gains new knowledge, and then ‘modus tollens’ the anti-physicalist conclusion as rather showing that prior to leaving her room, Mary didn’t have complete physical knowledge (of human colour vision, in particular), after all.

Chalmers’ argument also relies on the presence of an explanatory gap, as needed to make room for the conceivability of zombies—physical and functional duplicates of ourselves, lacking in qualitative consciousness—but goes beyond previous gap-based arguments in situating the conceiving at issue in an independently motivated framework—‘epistemic two-dimensionalism’ (E2D). E2D provides a way of partially reforging the link between a priority and necessity that was broken by Kripke’s identification of the necessary a posteriori: on the E2D strategy, a priori insight into what the extensions of our concepts would be in different scenarios (i.e., their intensions) can give us conditional modal knowledge: if the actual world is one where water is H2O, then necessarily, water is H2O; if the actual world is one where water is XYZ, then necessarily, water is XYZ. So we end up with a lot of a priori modal knowledge, with empirical considerations entering in just to discharge the antecedent of conditionals known a priori.

Now, if E2D is implemented via a conceiving-based epistemology of intensions (CEI), and given that zombies are conceivable, then the genuine possibility of zombies follows, which along with certain other assumptions might be seen as suggesting that qualitative consciousness is Strongly emergent. But as I argue, drawing on joint work with Stephen Biggs (‘Abductive Two-Dimensionalism: A New Route to the A Priori Identification of Necessary Truths’), E2D can and should be implemented as involving an abduction-based epistemology of intensions (AEI) rather than CEI; when E2D is implemented using AEI, there’s no clear case for thinking that zombies are genuinely possible. Key to the strategy here is Biggs’s and my view that, contrary to popular assumption (though not so different from views held by Kant and Carnap, among others), abduction is an a priori mode of inference (see our ‘The A Priority of Abduction’).

Given that explanatory gaps of whatever variety don’t suffice to indicate Strong emergence, what does? In the main, I think this is an empirical matter. The question to be asked here is: what are the empirical indications of the operation of a novel fundamental interaction? Luckily, we have a historical case to guide us here—namely, the discovery of the weak nuclear interaction. In that case, there was an apparent violation of a conservation law. Rather than accept the violation, a novel fundamental interaction was posited as needed to balance the books. Interestingly, a nucleus is a complex entity, so evidently physicists have no problem positing fundamental novelty arising only at a certain level of compositional complexity. I’m simplifying here, but the core idea is that apparent violations of conservation laws look to be a good criterion of a novel fundamental interaction, as a recognizable descendent of the British emergentist’s criterion of a failure of non-linearity. Conversely, should the requisite experiment be performed and no apparent violation of a conservation law observed, that would be sufficient grounds for sticking with physicalism and rejecting that anything like Strong emergence is going on—even in the presence of an insuperable explanatory gap. This line of thought, by the way, further undercuts the supposition that metaphysical dependence (whether Grounding or small-‘g’) is necessarily tied to metaphysical explanation.

3:16: Why do you think of free will as Strongly emergent?

JW: Libertarian free will is naturally understood in Strong emergentist terms, as involving a fundamentally novel power to choose in a way that is not law-governed—whether the laws are deterministic or indeterministic, no matter. Independent of the above empirical route to confirming cases of Strong emergence, I argue that the fact that we have direct introspective access to the phenomenon of seemingly nomologically transcendent free will provides the basis for a new argument for there actually being libertarian—Strongly emergent—free will, along the following lines:

1. We experience ourselves as seeming to freely choose, in ways transcending any nomological (deterministic or indeterministic) goings-on.

2. In the absence of good reasons to think that our experience of nomologically transcendent free will cannot be taken at realistic face value, we are entitled to take this experience at realistic face value.

3. There are no good reasons to think that our experience of transcendent free will cannot be taken at realistic face value.

4. We are entitled to take our experience of nomologically transcendent free will at realistic face value.

The main action concerns premise 3, and there are two sorts of reasons offered for rejecting this premise. The first is that such free will would be naturalistically unacceptable; but insofar as Strong emergence and associated novel fundamental interactions are in naturalistic good order, there’s no special problem here. The second is that such free will has been empirically disconfirmed—most saliently, by ‘Libet cases,’ which aim to compare the self-reported time of occurrence of a conscious choice to produce some physical behavior with the time of occurrence of certain unconscious brain states (‘Readiness Potentials’) associated with the production of the behavior. These studies have been interpreted as suggesting that the unconscious initiation of the physical behavior occurs prior to the time of the supposed choosing, such that the supposition that our free choices are determinative of our actions is illusory. But as I discuss, these studies admit of alternative interpretations (including those due to Tim O’Connor and Alfred Mele, among others) which do not have anti-libertarian import.I also offer a new alternative interpretation of Libet cases, on which the intention to choose and the brain activity are cotemporally initiated, but where it takes just a bit of time for this fact to consciously register as a complete thought in the agent’s mind. Thinking, and presumably also choosing, takes time. As such, a very small lag—less than half a second—between initiation and conscious recognition would be a natural concomitant of our mental decision-making processes, again compatible with nomologically transcendent free will. More generally, Libet’s assumption that “In the traditional view of conscious will and free will, one would expect conscious will to appear before, or at the onset, of the RP [Readiness Potential], and thus command the brain to perform the intended act” (1999, 49) appears to reflect an unmotivated understanding of transcendent free will as instantaneous and indeed as in some sense floating free of underlying physical processes.

Here attention to the characteristic features of metaphysical emergence proves useful. For first, the libertarian qua Strong emergentist will assume that mental features are cotemporally materially dependent on physical features; but second (as I discuss in the book) the cotemporal dependence base may be temporally extended rather than instantaneous. As such, one might reasonably maintain, as an available interpretation of Libet’s results, that the occurrence of a given Readiness Potential would not be prior to the event of choosing (as O’Connor’s and Mele’s alternative libertarian-friendly interpretations grant), but rather part of the temporally extended dependence base for an event of free choosing.

I confess that I’m relieved that there are cases to be made that free will is Strongly emergent. Nothing much turns on whether or not qualitative mental experience is physically acceptable, but if there’s really no nomologically transcendent free will, then much of we take ourselves to do and be would turn out to be a horrible fiction, much worse than being trapped in the Matrix.

3:16: You think that there is genuine metaphysical indeterminacy, don’t you? This is quite a shocker—the vagueness literature, for example, seems to be full of arguments denying metaphysical vagueness and arguing for some sort of semantic vagueness instead. So what’s your position, and how do push back against the deniers? Didn’t Evans have an argument against your position? Does your argument mean that quantum indeterminacy is a function of the actual world and not our ignorance?

JW: Yes, I do think that there is genuine metaphysical indeterminacy (MI), and quite a lot of it! Many goings-on seem to be indeterminate: the boundaries of objects, open future claims, certain properties of systems on various interpretations of quantum mechanics. On the face of it, the indeterminacy at issue in these cases is not semantic, much less epistemic—it’s not plausible that the seeming indeterminacy of a cloud reflects our not having decided exactly which molecules are the proper referent of a given use of ‘cloud,’ or that Mount Everest does have a perfectly precise boundary, but we just don’t know which one it is; and in the cases of open future and quantum indeterminacy, semantic and epistemic spins are even less appropriate.

Notwithstanding all this seeming MI, it has frequently been claimed that MI unintelligible and perhaps even incoherent. Most pressingly, Evans argues that the supposition of vague objects—objects with indeterminate boundaries—leads to contradiction. The argument is straightforward: suppose there is a vague object a . Then it is indeterminate, for some object b , whether a is identical to b . But it is determinate that a is identical to a . In that case, a and b have different properties: a but not b has the property of being determinately identical to a . So by Leibniz’s Law a is determinately non -identical to b : contradiction.

That’s a cute argument, but as it happens it applies only to one approach to MI—what I call a ‘meta-level’ approach, according to which what it is for a state of affairs a to be indeterminate is for it to be indeterminate which determinate (precise) state of affairs a is the case. This is the sort of account advanced by Ken Akiba, Elizabeth Barnes, and Robbie Williams, among others—effectively, it takes the apparatus of supervaluationist approaches to semantic indeterminacy, and gives it a metaphysical spin: it’s not our language, but the world, that is unsettled about various precise ways for it to be. On metaphysical supervaluationism, for example, what it is for Mount Everest to have an indeterminate boundary is for it to be indeterminate—for the world to be unsettled about—which precise boundary Mount Everest has. There are strategies for avoiding Evans’s contradiction on a meta-level account, but in any case it doesn’t strike me as naturally modeling many cases of MI. It’s metaphysically opaque how the world could be unsettled, right now, about which boundary Mount Everest has—notwithstanding that according to the supervaluationist the world is settled, right now, that Mount Everest has a determinate boundary. Plus, my own view is that macro-object boundary MI is “deep”: for any precise such boundary, it’s false that the macro-object has it. The problem is even more pressing for quantum MI: as George Darby, Brad Skow, and Claudio Calosi and I have argued, there’s no way to accommodate quantum indeterminacy on a meta-level supervaluationist approach, since on various interpretations of quantum mechanics, there are no classical, completely determinate worlds for the world to be unsettled between.

But a meta-level metaphysical supervaluationist account is not the only option. Recently I’ve introduced a different, ‘object-level,’ approach to MI (‘A Determinable-based Account of Metaphysical Indeterminacy’) on which this involves (not indeterminacy in what precise states of affairs are the case, but rather) indeterminacy in the states of affairs themselves. On my approach, what it is for some state of affairs to be MI is for (in the simplest case) the constituent object of the state of affairs to have a determinable property, but no unique determinate of that determinable. On a determinable-based account, for example, what it is for Mount Everest to have an indeterminate boundary is for it to have a determinable boundary property, but no unique determinate of that determinable. Note that there are two ways for the condition on failure of unique determination to be met—either by there being too many candidate determinates on the scene (this is ‘glutty’ indeterminacy), or by there being none at all (this is ‘gappy’ indeterminacy). The case of Mount Everest plausibly involves there being too many candidate determinations of the determinable boundary property, corresponding to different aggregates of matter in the immediate vicinity of the mountain. Other cases—say, involving open future indeterminacy, or value indeterminacy on some interpretations of quantum mechanics—might involve a system’s having a determinable property but there being no candidate determinates of that determinable at all.Evans’s argument can’t get started against a determinable-based (object-level) approach to MI; for on this approach it doesn’t follow from an object a’s being ‘vague’—that is, its having an indeterminate boundary—that it is indeterminate whether a is identical to some precise object b . On the contrary, from a ’s having an indeterminate boundary it immediately follows, on a determinable-based view, that a is not identical to any precisely boundaried object b . Moreover, I argue, the view is intelligible—in particular, in reducing MI to a pattern of instantiation of properties (namely, determinables and determinates) with which we are experientially and theoretically familiar. The view has other advantages, too—for example, unlike a metaphysical supervaluationist approach to MI, a determinable-based approach does not involve any sentential or propositional indeterminacy, and so is straightforwardly compatible with classical logic and semantics.

If I may be so bold, I think that the topic of MI is another case where recent significant philosophical progress has been made. Previously nearly everyone thought MI was unintelligible and perhaps even contradictory. That was wrong—properly understood, MI is intelligible and coherent, and so there is no in-principle barrier to taking the appearances of MI at face value, in cases of the open future, macro-object boundaries, quantum mechanics, and elsewhere. Nor does such accommodation require any revisionary logic or semantics—at least, on my approach. That MI makes good sense also opens the door to further applications. For example, in my book, I appeal to a glutty determinable-based understanding of macro-object boundaries to argue that such boundaries (hence the associated objects) are Weakly emergent, in having fewer powers than the determinate boundary properties upon which the determinable boundaries cotemporally depend. And in ‘Quantum Indeterminacy and the Double-slit Experiment,’ Claudio Calosi and I apply a glutty implementation of a determinable-based account of MI to provide an intelligible explanation of the interference patterns in the double-slit experiment. Effectively, a glutty implementation makes sense of how a single particle can go through both slits at the same time, allowing for self-interference without introducing the metaphysical correlate of a contradiction.

3:16: It sounds as if your metaphysical projects frequently build on each other! Would you say that you are a systematic philosopher?

JW: Well, I try to be consistent, but I’m not systematic in the sense of trying to account for some large swathe of phenomena in light of some specific epistemological or metaphysical commitments. I rather just tend to trust my metaphysical instincts and methodological inclinations when approaching a given issue or problematic. Luckily enough, doing so has resulted in views that fit together pretty well, and which sometimes inform each other in ways I didn’t antecedently anticipate.

3:16: And for the metaphysicially curious, are there some books you can recommend to the readers here at 3:16?

JW: I’ll recommend two that I have read and gotten a lot out of lately.

First is Lady Mary Shepherd’s Essay upon the Relation of Cause and Effect, Controverting the Doctrine of Mr. Hume, Concerning the Nature of that Relation. It’s absolutely brilliant; Shepherd lays waste to Hume’s argumentation, and more importantly she offers strikingly original positive accounts of causation, causal epistemology, and objects which are clear anticipations of, e.g., Mill’s method of difference, Anscombe’s causal singularism, and contemporary dispositional essentialist accounts. I survey her critical and constructive contributions in ‘On Mary Shepherd’s Essay upon the Relation of Cause and Effect’ , forthcoming in Eric Schliesser’s second Neglected Classics volume.

Second, I recommend Karen Bennett’s Making Things Up. Bennett’s a wonderful writer and an incisive thinker; we disagree about many things, but (or maybe ‘and so’) I always get a lot out of thinking about her work. Here she advances her own preferred package deal for understanding metaphysical dependence and its connection to fundamentality, offering an excellent overview of the state of play as regards these notions along the way.