Dispositional Realism and Scientific Metaphysics


Chapter 4 marks a change in focus for Chakravartty’s project. In Part II, he begins looking at “more detailed illustrations of putative exercises in scientific ontology” (C, 99). However, Chakravartty stays away from explicit scientific content, instead deciding to focus on implicit scientific content, as it has been discussed far less and provides better examples of morals for scientific ontology (C, 100). In the supplementary reading, Amanda Bryant seeks an epistemological framework for a scientific metaphysics. In order to do so, she attempts to define a principle that prefers the simpler of two scientific theories. Bryant uses Okham’s razor as a mechanism to prove that a well-constrained, robust theory, is epistemologically preferable to a permissive, less-robust theory (this will be discussed in greater detail later).


The main thrust of Chakravartty’s argument in this chapter centers around the subject of dispositions. He starts out with an examination of dispositional properties, defining a disposition as “the ancient idea of a causal power,” and “a property that causes something to behave in a certain way” (C, 100). These properties contrast with categorical properties. A categorical property is static by nature. For example, the length of an object is always the same. Dispositional properties, however, can differ by circumstance. For example, the fragility of an object can differ depending on its surrounding environment. Bryant implicitly touches on this in her paper, as she discusses permissive and constrained theories. She posits that constrained theories are more likely to be true. Proponents of empiricism, and therefore constrained theories, are more agreeable to categorical properties, while dispositional realists (scientific metaphysicians) tend to side more with dispositional properties, which lend themselves to more permissive theories, or at least it appears that way on the surface. This will be discussed more later. 

Dispositions used to be a fixture of philosophy, but fell on hard times during the early modern era. This might have been a result of the early modern’s tendency to split away from science (thanks for the history lesson, Professor). This ideological split makes sense, as dispositions allow for explanations of phenomena that would otherwise go unexplained. Scientists may ask why a certain entity behaves in “x” way. A dispositional realist would answer that the entity in question is disposed to behave that way (C, 101). Empiricists reject this view. Instead, they would say that there is nothing to explain past those phenomena simply existing. Although Chakravartty finds dispositions compelling, he does not believe that dispositional properties prove the existence of dispositions.

Scientific Realism

Chakravartty posits that dispositions can provide common ground for opposed aspects of scientific realism: entity and structural realism. Without dispositional realism, they are incompatible viewpoints. Dispositions are agreeable with entity realism because properties can be considered dispositions. Entity realists find these to be important, as they prove the existence of certain entities (C, 107). Regarding structural realism, dispositions can also serve as relations, as dispositions dictate how the manner in which the environment is supposed to behave. Dispositional realism reconciles the two opposing viewpoints, while also unifying our concepts of entities and properties with the causal process (C, 110). Chakravartty further drives this point home, positing that scientific laws are usually just relations between properties. This fact also does work for the dispositional realist, as properties are unified with all kinds. Chakravartty finishes this section by stating that, by finding dispositional realism attractive, one must in some way agree with scientific realism. However, as he recognizes, due to the metaphysical inferences, most people who agree with this position were already in his camp, or as he said, he is “preaching to the converted.”

Explanatory Power

One might think that there is a philosophical stalemate between dispositional properties and its deflationary analyses. However, there are new, transcendental arguments for dispositions. 

            P1: Objectionable claim regarding scientific practice

            P2: The giving of relevant explanations presupposes Q (the reality of dispositional   properties)

            C: Dispositional realism

Chakravartty then moves to discussing the two main arguments that concern explanatory practice. The first argument comes in two flavors, dispositional regress and dispositional exercise. The second argument is the argument from abstraction.

Chakravartty starts with the dispositional regress and exercise arguments. For regress, Chakravartty starts by stating that dispositional concepts explain the behavior of entities. Basically, what he says is that as scientists discover more, which should dispel the need for dispositions, there will always be new, finer grained issues that cause the need for even more dispositions (C, 113). 

He then goes through the disposition exercise argument. This argument centers on the fact that sometimes dispositional properties are acting, or “triggered,” without the actual manifestation of a certain behavior. Chakravartty uses an example from Nancy Cartwright, describing two negatively charged particles that are exactly balanced. Despite the undeniable forces at play, the particles do not move. Without an appeal to dispositional realism, there is no explanation for this event. This argument makes a case for dispositional realism, as dispositions can exercise without manifesting, which is something that categorical properties cannot do. It is important to mention that these exact situations (which are inherently inexplicable without dispositions) prove that Bryant’s epistemological framework for scientific metaphysics are more apt for justification, and not discovery. 

Lastly, Chakravartty goes through the argument for abstraction. Transcendental in nature, it is focused on the efficacy of scientific methodology in case of abstraction (C, 117). Basically, he argues that abstractions could not be used, if not for the fact that they reveal information about dispositions. As an example, Chakravartty uses the application of laws from one closed system being transferred into another, non-isolated system. Closed conditions abstract from naturally occurring phenomena in this world, and laws only describe isolated systems. However, scientists regularly apply this knowledge to non-isolated systems. Chakravartty argues that laws should be interpreted as describing dispositions, saying “such dispositions often play a role in more complex situations, even if the precise manifestations they produce in isolation are mitigated or altered when combined with other dispositions” (C, 118-9). However, there are no guarantees about successfully exporting knowledge into more complex systems. Due to the lack of this guarantee, Chakravartty posits that abstraction provides no argument for the reality of dispositions (C, 120). Dispositions could just be the result of circumstance interacting with categorical properties.

Consolidating Scientific Knowledge

Chakravartty then moves towards the explanation of his argument. He allows that the conclusions of his prior efforts to explain science result in conflicting judgements, in which incompatible models incorporate incompatible assumptions. However, he believes that dispositions can rectify this problem. Chakravartty acknowledges the fact that models and theories often end up producing inconsistent descriptions (C, 121). However, being able to resolve these different descriptions into a unified picture would be good in the pursuit of knowledge. He uses water as an example. Water is a continuous, incompressible medium. It is also a collection of discrete particles. However, an entity cannot be both a continuous medium and a collection of discrete particles. 

            Incompatibility, to the dispositional realist, could just be a description of the different dispositions. Rather than attempting to describe what a fluid is, Chakravartty believes that dispositional realism could allow us to know what a fluid does. In other words, dispositions allow us to look at the behavior of an entity instead of its nature. This is where Bryant’s thesis is applicable; by constraining their hypotheses, scientists can increase the likelihood that those hypotheses are correct, which, in turn, makes them epistemologically preferable. The resulting concern is that dispositional realists have strayed from the pursuit of science — science is supposed to be about discovering and justifying the nature of entities (C, 124). Through an empiricist lens, that pursuit would be achieved by understanding the properties of an entity. However, it is important to remember that for dispositional realists, properties are dispositions. Chakravartty says it better:

“Thus, a description of the dispositions of something to behave in the ways it does, under the kinds of circumstances that elicit those manifestations, is unavoidably part of the description of the nature of the thing” (C, 124). 

            So what does dispositional realism do? According to Chakravartty, it’s a placeholder (C, 124). Saying what a thing does is much more flexible than what a thing is. So, although it is not as strong, dispositional realism does serve a purpose. Bryant agrees, saying that “it is better to have a descriptive and explanatory theory that is only somewhat likely than to have a theory that is not particularly descriptive or explanatory, but a good deal likelier” (B, 12). Until scientists can truly discover the nature of things, dispositions give them something to work with. By not making a genuine ontological commitment, the dispositional realist helps themselves. Furthermore, as Chakravartty posits, discussing the relevant dispositions of a thing is to describe the ontology of said thing (C, 126). He knows that this does not settle the perennial debate, but thinks that this is a step in the right direction. 

Property Identity

Chakravartty then confronts the issue of what makes a given property the property that it is, as opposed to another. His answer: the dispositions. Empiricists say that properties are “quiddities,” which basically posit that the nature of the property itself is unknowable (C, 129). Bryant agrees with this evaluation, which is why she sides with Chakravartty in promoting scientific metaphysics. Nothing can be said about a given property other than it is different than other properties. This is the big logical conflict with the empiricist ideology that Chakravartty wants to point out: the philosophy that holds itself as the best method of observation, but also holds that it cannot describe the differences it discovers. Chakravartty allows that science cannot answer everything. Metaphysics will still have some role to play. Bryant buttresses Chakravartty’s opinion, saying “we should tie metaphysics to science because the road to knowledge is empirical, and because science seems to be a paragon of empirical investigation” (B, 2).

Naturalism and the Grounding Metaphor

  • In Hopes of Demarcating Scientific Ontology

What distinguishes scientific ontology from non-scientific ontology? Chakravartty proposes the norm of naturalized metaphysics (NNM):

…the principle that scientific ontology is properly delimited by metaphysical inferences and propositions that are sufficiently informed by or sensitive to scientific-empirical investigation as to provide or constitute ontological knowledge relating to the sciences. (67)

However, consonant with his voluntarism, there can be substantial differences about what counts as “sufficiently informed by or sensitive to scientific-empirical investigation.” As he puts it, “no stance in, no ontology out” (65-66).

            At least one place where these differences play out is in delimiting the subject matter of the sciences that is germane to scientific ontology. There are at least two places where this affects how the NNM is applied:

  • The explicit subject matters of the sciences are things that can fall out of reading the sciences at face value. For instance, molecular biology’s explicit subject matter includes gene transcription, DNA, and RNA.
  • The implicit subject matters of the sciences, “things whose natures are not the face-value targets of scientific work, but which are rather mentioned in passing” (69). This includes properties, causal relations, laws of nature, possibilities, and necessities.

Here are some of the questions that arise which Chakrvartty appears to think are stance-dependent. (1) Should scientific ontology restrict itself to explicit subject matters? (2) If scientific ontology is not restricted to explicit subject matters, then which implicit subject matters are proper targets of analysis? Different scientific ontologists may diverge in their applications of the NNM in answering these questions.

  • On Conflating the A Priori with That Which is Prior

Some claim that science presupposes metaphysics; others, such as Chakravartty, speak of metaphysical inferences. What’s at stake in this distinction?

A scientific domain D presupposes a metaphysical claim M if scientific investigation in D would not be possible without M.

  • Examples: measurement presupposes that quantities exist. Chakravartty also mentions classical mechanics presupposing that physical spaces obeys the axioms of Euclidean geometry as another example.

Some who appear skeptical of metaphysical inference accept that science frequently presupposes metaphysics. (Who? Chakravartty does not say.) How is this a coherent position? Chakravartty three possibilities:

  • First Possibility: “Metaphysical” presuppositions aren’t really metaphysical

The first possibility runs as follows:

P1.       Metaphysical presuppositions are not a priori.

P2.       The conclusions and criteria of evaluation in metaphysical inferences are a priori.

P3.       Only a priori claims are “really” metaphysical.

C.         So, metaphysical inferences, but not metaphysical presuppositions, are “really” metaphysical.

Chakravartty criticizes P1, arguing that presuppositions cannot be directly observed. “it was not because the geometry of spacetime was somehow empirically detected to be non-Euclidean that Einstein ushered in a new way of thinking about spacetime with his theory of general relativity.” (74)

  • Note: Chakravartty isn’t very clear about this, but I think the implicit point seems to be that there is a metaphysical inference from the predictions of relativity theory to the metaphysical presupposition that space is non-Euclidean.
  • Second Possibility: Presupposed metaphysics is less problematic than inferred metaphysics, version 1

Here’s the second way of cleaving metaphysical presuppositions from metaphysical inferences:

P1.       Metaphysical presuppositions do not concern ontology.

P2.       Metaphysical inferences do concern ontology.

P3.       Only metaphysics that concerns ontology is problematic.

C.         So, metaphysical inference, but not metaphysical presupposition, is problematic.

Chakravartty argues that the most plausible way of making P1 true is to adopt a deflationary metaphysics, in which putatively metaphysical claims are really about something non-metaphysical (for instance, merely about social practices in the scientific community.) However, deflationists will also reject P2. So, deflationism cannot fund this argument.

  • Third Possibility: Presupposed metaphysics is less problematic than inferred metaphysics, version 2

P1.       Metaphysical presuppositions are often tacit.

P2.       Metaphysical inferences are often explicit and deliberate.

P3.       Only explicit and deliberate metaphysics is problematic.

C.         So, metaphysical inference, but not metaphysical presupposition, is problematic.

The problematic assumption here is P3. Why think that something’s being explicit is problematic and something’s being tacit is not?

  • How Not to Naturalize Metaphysical Inferences

What exactly is the relationship between science and scientific ontology, such that the latter can be distinguished from other “non-scientific” ontologies? Chakravartty considers two proposals.

  • The Heuristic Conception

This approach to naturalized metaphysics, associated with Quine, sees philosophy as doing important conceptual preparatory work before handing off a topic of research to the empirical sciences.

Chakravartty objects that the heuristic conception is always out of time, as it were. We would have no way of knowing whether we were doing scientific ontology now, since it could only be redeemed by future science.

  • The Continuity Conception

Philosophy should be continuous with science’s aims, methods, subject matters, and criteria of evaluation.

Chakravartty thinks that this is more or less correct, save for the continuity of external subject matters with internal ones that are more philosophical in nature. Roughly, this means that science’s claims about explicit subject matters “ground” scientific ontology’s claims about its implicit subject matters. As Chakravartty notes, this grounding metaphor is in need of unpacking.

For instance, there is not a tidy division of labor with science (in say, its explicit subject matter) providing a posteriori constraints on ontology’s a priori claims. As we’ve already seen, science itself is fraught with a priori claims.

  • Unpacking the Metaphors: “Grounding” and “Distance”

The “ground” of scientific ontology is empirical inquiry.

“Distance” from this ground can be construed in terms of epistemic risk—given the empirical inquiry in question, what is the probability that the conclusion drawn from it (via metaphysical inference) is false?

Epistemic risk is a function of two things:

  • Empirical vulnerability: “how susceptible a proposition is to empirical testing.” (85)[1]
  • Explanatory power: “a measure of how well a metaphysical inference or resulting proposition satisfies the criteria typically associated with good explanations of the data of observation and experience,” such as “simplicity, internal consistency, coherence with other knowledge, and the capacity to unify otherwise disparate phenomena.” (87)

The more empirically vulnerable a statement is, the less its explanatory power and its epistemic risk.

These pull us in opposite directions: greater empirical vulnerability is good but greater explanatory power is also good. So, they trade off each other.

  • Theorizing versus Speculating

Naturalized metaphysicians frequently pride themselves on doing something akin to high-level scientific theorizing. They contrast this activity with the speculation characteristic of more traditional metaphysics.

Chakravartty contends that “There is no objective distinction between theorizing and speculating in the context of scientific ontology.” (89)

He argues for this as follows:

P1. If an objective distinction between theorizing and speculating exists, then there is a fact of the matter about the appropriate level of epistemic risk, i.e., the balance between testability with explanatory power, when drawing inference from the empirical content of science.

P2. There is no fact of the matter about the appropriate level of epistemic risk when drawing inference from the empirical content of science.

C.   Therefore, no objective distinction between theorizing and speculating exists.

The contentious premise is P2, so he offers some examples to motivate it. The only one that he really discusses in any detail is novel prediction. A novel prediction is an unexpected (typically precise) prediction that turns out, upon subsequent investigation, to be true. When a theory makes a novel prediction, its empirical vulnerability increases, so the epistemic risk in accepting it decreases. Does this mean that the following is true?

All and only theories that make novel predictions exhibit an acceptable level of epistemic risk.

If so, there would be a fact of the matter about the appropriate level of epistemic risk (P2 in the previous argument would be false.) However, Chakravartty argues that many good theories do not make novel predictions but are explanatorily powerful (natural selection). So, it cannot be that the absence of novel predictions can be used to rule out some metaphysical approaches as non-scientific ontologies.

[1] A more standard word for this is “testability.” This more conventional word-choice seems preferable in my opinion, since, for Chakravartty, epistemic vulnerability is a good a thing, yet there are many cases in ordinary language in which vulnerability is a bad thing (vulnerability to attack, for example).

Bas van Fraassen, The Empirical Stance, Chapter 2

1. What is empiricism?

            Your first encounter with the term ‘empiricism’ in a philosophical context may well have been in Early Modern, where empiricism was used as a wide-net descriptor for a host of rather diverse thinkers – in my version of the class it was Berkeley, Locke, and Hume – who believed the foundation of knowledge to be experience, accrued via acquaintance with empirical things, chief among them the objects of sensory experience. It is contrasted with ‘rationalism,’ which sees the mind and its faculties of rational inquiry as the foundation of all knowledge claims.

When we talk about empiricism in this class, the above isn’t what we mean, exactly, but it’s not totally unrelated. Van Fraassen says the rationalism/empiricism distinction was primarily made as an easy way to taxonomize pre-Kantian thinkers, which then allows professors to present Kant straightforwardly as the synthesis of these two schools. That’s fine, but it doesn’t exhaust the word. There are plenty of major post-Kantian philosophers who are also labelled as ‘empiricists,’ despite not referring to themselves as such (e.g. Mill). Are they just different terms? Van Fraassen says no — when we call a view ‘empiricist,’ we just mean that it denies some things and explanations beyond experience. Basically, if there are some philosophical theories and views that are totally focused on trying to explain what things are and why they are the way they are, and which argue for the existence of things we cannot access, then we should roughly sketch empiricism as the opposite: any robust philosophical view or theory which rejects demands for ultimate explanation and rejects attempts to postulate things beyond experience.

Historically, then, empiricism identifies a trend more than any one view; wherever there is some strong metaphysical theory, be it Platonism, Cartesianism, or some sort of continental gobbledygook about Dasein, there inevitably rises some brand or another of empiricism, whose proponents dare to say ‘enough!’ and cast off the yoke of systematized metaphysics and putative objects, bringing philosophy, as Locke said, back out of the ocean of mystery and into the realm of human understanding.

What does this have to do with science?

As discussed in Chakravartty, scientific theories seem to posit a lot of entities, forces, and other things that we either can’t apprehend without the aid of instruments (atoms), or can’t apprehend period (causation). The realist view of science will say that a good number of these things, even though we don’t have direct acquaintance with them, are real, in the same way that you are real.

But if we understand science this way, aren’t we just doing metaphysics of another sort? After all, if I demand to know why I fall down every time I jump, it seems like I’m not just asking how I should think about why I fall – it also seems like I want some more fundamental, behind-the-scenes why, and if there’s something we theorize as causing me to fall, it’s attractive to say that this something isn’t just a useful fiction, but it’s also real; after all, it seems unlikely that theories of gravitation could make incredibly accurate and consistent predictions unless they’re tracking something that’s really out there, beyond us. It’s intuitively attractive, then, to say that the putative objects put forward by our best theories are real, but in doing this, we must understand the sense in which the structures and objects posited are metaphysical ones – they go above and beyond what experience alone seems to present to us. Realists, of course, think this is a feature, not a bug, and are happy to commit to believing in plenty of these putative entities.

The empiricist response would look like this: we might have a theory of gravitation, and it’s a good theory. But it’s only good because it describes the things we want it to describe, and does so pretty consistently and accurately. Even though it’s good, that doesn’t mean it actually answers the real, outside-our-mind why of what’s going on, and there’s no good reason for us to say that the things it’s talking about are really there – they’re useful inventions which capture all the relevant features of what’s going on, but we have no real way of checking to see if they’re right – after all, there are lots of other things we could make up that presumably explain why I fall when I jump pretty accurately – that doesn’t mean we should say they’re actually there, right?

Empiricism, then, describes a kind of scientific anti-realism which still talks about atoms, and quantum particles, and black holes, but whose advocates, when questioned more deeply, will claim to use these terms more for reasons of parsimony. It would be wrong, according to them, to say science can give us the tools to find things beyond experience – all it can give us are the tools to construct explanations which make sense to the human mind and adequately predict and track the relevant phenomena.

2. What does it mean to hold empiricism as a view?

            So now we might say: “Well, I’m convinced. I’m an empiricist now, which means I believe the following: the foundation of all knowledge is experience!” It’s tempting to think this way: when we say we subscribe to a view, we often claim that taking the view just means saying ‘I believe X,’ where X is some factual statement.

            Van Fraassen thinks this doesn’t work. Why? First, he claims the empiricist must make the above assertion without justification, since the justification for such a claim would either be a) that the only claims accepted by the empiricist are those grounded in experience (which is circular) or b) that there is something else grounding this justification (what grounds that something else? This is an infinite regress). Granting this, the problem with empiricism is as follows: The empiricist’s central belief is that we cannot have a priori proof or denial of a factual proposition about the world, but this central belief is itself such a factual proposition about the world. Empiricism, formulated so, is vulnerable to a reductio ad absurdum – it must admit the admissibility of contrary views (for example, how would an empiricist deny the claim that “some knowledge is grounded by things distinct from experience,” if they are only looking to experience to verify such claims?) while also holding the inadmissibility of such views as its central dictum. The ultimate conclusion is that empiricism’s central claim seems merely putative, with no critical bite and no way of placing itself above any sort of metaphysical theory, despite those views being the central object of its theoretical ire!

Stance Time

            To escape this hellish pit we’ve dug for ourselves, van Fraassen thinks we have to redefine what it means to hold a position. What if being an empiricist wasn’t just synonymous with ‘believing in a bunch of propositions.’? Van Fraassen says that we should instead treat empiricism attitudinally; being an empiricist means that you have a certain attitude towards science and value it for certain ends, and it is this stance which determines which beliefs about the world you may presuppose, and which new ones you’re willing to accept. This looks like familiar territory, overlapping with Chakravartty. But why does this solve the problems from the last section?

            Simply put, thinking of empiricism of a stance now means that its principal disagreements with metaphysics will not be factual disagreements, but rather disagreements based on non-cognitive things, like values. Now, there is room for meaningful disagreement. Van Fraassen cites Feyerabend in pointing out that this view of stances dovetails nicely with how we tend to conceive of the limits of scientific admissibility; the problem with flat-earthers is not that their claims are intrinsically inadmissible (after all, the empiricist may well say we can’t really know what shape the Earth is), the problem is actually that the flat earther has certain attitudes and values regarding how science is done, and there is indeed a possibility that these values might, if we disagree, put their views outside the realm of legitimate scientific inquiry.

3. What about non-empirical views?

            The above analysis is somewhat specific to empiricism, since the adoption of stances was a move primarily made to evade a reductio ad absurdum argument particular to the dogmas of empiricism. Is there any reason to think, say, a devoted materialist should care to think of their views as reflecting a stance?

The materialist might say no, that materialism is just synonymous with the belief that ‘matter is all there is,’ or something to that effect. But van Fraassen thinks this is a form of ‘false consciousness’ – the materialist, even if they aren’t wrong per se, is misunderstanding what their own position is. The weird thing about materialism, as van Fraassen points out, is that, throughout the history of science and philosophy, there are always materialists, and yet materialists of yore often not only held different beliefs than the materialists that followed, but likely would have held as inconceivable the beliefs of their successors – would an ether theorist have simply balked at the possibility of their being an object such as a photon, or indeed, spacetime? Would a Newtonian-era physics have allowed for an account of quantum objects as material? It seems likely that, in it at least some cases, the answer is no.

            So, does materialism, as a term, just extend over a concatenation of a bunch of discrete and incommensurable beliefs? Maybe. But we have some clues to indicate that this isn’t what’s going on. Look, for example, at how materialists react during scientific revolutions; when new scientific paradigms are suggested, the old scientists often embrace the new theories and continue to call themselves materialist, even though they have adopted a new set of views about material things whose putative properties might have disqualified them as ‘physical objects’ in previous formulations. Yet the materialist scientist doesn’t seem to see any problems here, and will likely offer one of two solutions provisionally proffered by van Fraassen.

The first option to say is “Well, matter is still everything, it’s just that my definition of ‘everything’ was expanded, and so it turns out that matter is a little different than what I thought.” The second option is to say “well, there’s no contradiction, because materialism is really just a completed physics. These new entities are a part of physics, and so, while they do stuff I didn’t previously consider options for material things, I see no problem with calling these new things material, in virtue of their being part of a (now more complete) physics.”

I hope it’s clear what’s odd about both of these responses; they’re putting the cart before the horse. The materialist position almost always seems to justify its claims not merely presently, but futurely. They are saying :“Not only are all putative objects posited by scientific theories physical ones, but future scientific theories will also posit only material objects, never immaterial ones.” Materialism is being presumed, not so much as a set of dogmas, but as a mold in which all new scientific developments and theoretical objects are taken and cast in some material capacity. Materialism, then, seems less like a set of defensible propositions, and more like an attitude or policy which determines not only how one treats their knowledge, but how one intends to treat future knowledge. The reasons for attributing physical-ness to ether, and light, and black holes, and dark matter, are at their core non-cognitive in origin – a stance.


Van Fraassen doesn’t give an exhaustive treatment of all possible positions, but empiricism and materialism, broadly construed, seem to capture the vast majority of debates going on in philosophy of science regarding what science can tell us (and regardless, his treatment of materialism applies just as well to physicalism and other similar-to-materialism-but-not-materialism positions). The implication that most or all philosophical positions on scientific inquiry are actually stances should reshape how we understand scientific disagreement and set the parameters of admissibility in the sciences.

Science & Metaphysics, Then and Now

Note to students: As I mentioned in class, this is written more in the form of a handout for you. Your own summaries might benefit from being a bit more prose-y, as my first post and Farhan’s post were. Additionally, the discussion questions here are simple: there are a battery of arguments. As you read through them, ask yourself, “Do I accept these arguments? If not, which premise do I reject?”

Main Objective: Chakravartty seeks to refute the claim that some conceptions of scientific ontology require no metaphysical inferences. More positively: all conceptions of scientific ontology require metaphysical inferences.

  1. What are metaphysical inferences?

Metaphysical inferences are a species of Inference to the Best Explanation (IBE). This inference pattern is typically represented inductively:

            P is a fact in need of explanation.

            Q is the best explanation of P.[probably]


Roughly, an explanation best explains a phenomenon if and only if it optimizes the following kinds of criteria: simplicity, internal consistency, coherence with already-established science, scope, and unification.

Unlike other IBE’s, metaphysical inferences have pronounced a priori dimensions. Chakravartty provides three indications of what he means by this (35):

  • The explanatory hypothesis, Q, is the product of conceptual analysis.
  • The explanatory hypothesis, Q, describes a state of affairs that cannot be observed through the use of the unaided human senses.
  • The criteria that make one explanation better than another are defined and weighted by one’s intuitions.

Philosophers are likely to disagree about whether a particular IBE counts as a metaphysical inference, owing to the following sticking points: How strictly is “a priori” being defined?

  • For instance, if its antonyms, “a posteriori”or “empirical”, are restricted to claims that are knowable by the unaided human senses, then metaphysical inferences are legion.
  • However, there are more liberal notions of “a posteriori” that include any claims that are:
    • “Sensitive to” observation or
    • Knowable via the outputs of instruments such as microscopes and telescopes.

This more liberal notion of “a posteriori” will have a more restricted set of IBEs as metaphysical inferences.

2. Is Science Inherently Metaphysical?

Because science emerged from philosophy and theology, there is no doubt that earlier science is fraught with metaphysical inferences. However, what of contemporary science? Chakravartty looks at the arguments for and against.

2.1. Anti-Metaphysics: Empiricism

E1.       If some metaphysical inferences are sound, then we should accept some claims that posit unobservable entities.

E2.       We should not accept any claims that posit unobservable entities.

E3.       Therefore, no metaphysical inferences are sound.

2.1.1. Chakravartty’s “Zombie Argument” against E2

Z1.       If empiricism is true, then we should believe that science aims only at knowledge of the observable.

Z2.       Aims are unobservable.

Z3.       Therefore, if empiricism is true, then we should believe some claims that posit unobservable entities.

In other words, if empiricism is true, then E2 is false and the empiricists’ ban on metaphysical inferences is unsupported.

2.1.2. Chakravartty’s “Empirical Metaphysics Argument” (55-57)

EM1.   If empiricism is true, then observable entities must be distinguishable from both unobservable entities and “observable non-entities” (such as hallucinations, optical illusions, etc.)

EM2.   In at least some cases, distinguishing observable entities from unobservable entities and observable non-entities requires sound metaphysical inferences.

EM3.   Therefore, if empiricism is true, then at least some metaphysical inferences are sound.

2.2. Pro-Metaphysics

M1.      If successful science makes metaphysical assumptions, then some metaphysical inferences are sound.

M2.      Successful science makes metaphysical assumptions.

M3.      Therefore, some metaphysical inferences are sound.

2.2.1. Chakravartty’s “Reinterpretation Argument” against M2

R1.       If any putatively metaphysical assumption can be reinterpreted as an empirical assumption, then successful science need not make metaphysical assumptions.

R2.       Any putatively metaphysical assumption can be reinterpreted as an empirical assumption.

not-M2.   Therefore, successful science need not make metaphysical assumptions.[2]

2.3. Some Thoughts…

While it is historically accurate to describe empiricists as subscribing to a thin notion of the “empirical,” it is not clear why this is a necessary aspect of empiricism.

Furthermore, many empirical claims do not need to be justified via IBE of any sort. Presumably, they can be justified by observation.

If we combine these two points, then a liberal notion of the empirical provides a stronger anti-metaphysical argument than the one presented in §2.1: lots of things are observable and many of them can be known without any appeal to IBE. The remaining question would be if those that can only be known by IBEs are metaphysical inferences.

3. Epistemic Stances Regarding Scientific Ontology

Chakravartty restates some of his core ideas about stances, but emphasizes a few things that were understated in Chakravartty (2018):

  • Stances are non-propositional.
    • Propositions can be true or false and can be believed. Stances are neither. Instead of being believed, stances can be “adopted.”
  • They are orientations, clusters of attitudes, commitments, and strategies “relevant to the production of allegedly factual beliefs.” (p. 47; This seems a bit broader than an epistemic policy, but perhaps not.)
  • They can coexist with each other:

Where someone adopting the metaphysical stance may be tempted to affirm certain propositions regarding unobservable objects, events, processes, and properties, the holder of the empiricist stance does not deny such claims. Rather, the empiricist simply has no beliefs at all concerning such propositions… In this way the latter’s scientific ontology may be a subset of the former’s… (50)

4. “Metaphysical inference” versus “metaphysical inference”

Consider two IBEs:

Numbers IBE
The applicability of mathematics to science is a fact in need of explanation.
Numbers’ existence best explains why mathematics is applicable to science. [probably]
Numbers exist.
Gravity IBE
That apples fall is a fact in need of explanation.  
Gravity’s existence best explains why apples fall. [probably]
Gravity exists.

While most philosophers would agree that the “Numbers IBE” is a metaphysical inference, they might well disagree about whether the “Gravity IBE” is a metaphysical inference. Those who claim that Gravity IBE is non-metaphysical might claim that, at most, it is a metaphysical inference, but unlike the Numbers IBE, it is not a Metaphysical inference.

One might think that once we can pinpoint the “objective boundary” between little-m and Big-M metaphysical inferences, we can resolve some debates about scientific ontology. Chakravartty disagrees:

There is no boundary. Rather, there is something like a continuum ranging from lesser to greater magnitudes of metaphysical inference, and disagreement regarding which parts of this continuum are epistemically solid enough to serve as a basis for scientific ontology” (52).

5. Metaphysics without Scientific Ontology?

Most “professional” metaphysicians are not philosophers of science. (They are frequently called “analytic metaphysicians.”) They see themselves as doing something: (a) more “general” or “fundamental” than scientific ontology—but they also see what they’re doing as: (b) independent of scientific ontology. Chakravartty argues that these two claims are in tension.

            Specifically, if metaphysics is more general/fundamental, then it must show that it can subsume more specific/derivative scientific claims under its framework. However, this means that it depends on scientific ontology.

Chakravartty, Anjan. 2018. “Realism, Antirealism, Epistemic Stances, and Voluntarism.” In The Routledge Handbook of Scientific Realism, edited by Juha Saatsi, 225-236. Routledge.

[1] However, it can also be represented deductively:

It is rational to believe the best explanation of a fact in need of explanation.

P is a fact in need of explanation.

Q is the best explanation of P.

Therefore, it is rational to believe that Q.

Indeed, this might help us to more clearly see where stances come in—the “rational-to-believe parameter.”

[2] Note the switch to “need not” in this claim from the implication that successful science “(actually) makes” metaphysical inferences in the original pro-metaphysics argument.

Week 2: Psillos

Psillos critically examines the epistemology of Bas van Fraassen, not with regard to any specific questions about realism and antirealism, but with its implications for rationality. In particular, he takes issue that van Fraassen’s conception of rationality has no compelling story about prior beliefs, ignores the content of belief, unfairly rejects IBE,  and calls rational what we really ought to be able to call irrational.

Background: Sailing between Bayesianism and Tradition

To understand van Fraassen’s view of rationality, let’s first get a handle on the positions that he is trying to mediate between. 

Traditional Epistemology: 

Traditional Epistemology is not a particularly well defined position per se, but the relevant features of it for this debate is that it suggests that we are rationally obligated to follow ampliative rules in our belief formation. A rule is ampliative if it (supposedly) allows for one to derive conclusions that extend beyond the premises. A way to think of it is that they are arguments that can be good but not sound in the strict sense. In particular, the ampliative rules in question are Induction and Inference to Best Explanation (IBE). Induction is the inference to a general law from a sufficient set of particular instances (eg. every day of my life, the sun has risen, thus the sun will rise everyday) and IBE is the belief in the explanation that best suits the evidence (eg. all of my electronics stopped working at the same time, so the power is out). This is especially important because in traditional epistemology, since for a belief to be rational, it must be justified, which leaves nothing to choice. Even though these inferences are not deductive, we say that it is rational to make them, and more saliently, irrational not to

Bayesian Epistemology:

Bayesian Epistemology designed to put induction in purely logical terms. Bayesians do that by focusing on beliefs not as binary belief and disbelief, but as a range of credences one can hold towards a proposition. In doing so, inductive inferences can be treated with the same level of deductive rationality as ordinary propositional logic. There are two views on rationality within Bayesianism: synchronic and diachronic. Synchronic Bayesianism constrains rational belief by whether or not beliefs can be held at the same time coherently. The corresponding rule in ordinary logic is the principle of noncontradiction. Since credences are a range, irrationality (to a synchronic bayesian) is demonstrated with a Dutch Book argument. These show that if you were to place a series of bets that correspond perfectly to your beliefs at the same time, you would suffer a loss (imagine a situation in which a coin would be flipped 100 times and you bet $150 dollars that it would land heads 75 times and tails 75 times; you would necessarily lose $50). A Bayesian can go another step and constrain the rules by which beliefs must be updated. This is Diachronic Bayesianism. Diachronic Bayesians constrain rational belief by whether or not one changes their belief in accordance with evidence (on top of already having them cohere in the synchronic sense). This corresponds to a belief in ordinary logic that if you believe that P and that  P-> Q, you are rationally obligated to believe Q. This is also demonstrated with a Dutch Book argument (imagine a situation in which you believe that there is a 1% chance that a coin is rigged to always land heads, if you were asked to bet (out of $100) on whether the coin will land heads, you should at first bet ~$51, but if I then flipped the coin a thousand times and they all landed heads, you would be irrational to not start betting higher). This process of updating beliefs is called conditionalization and follows the form Pr(H) = Pr(H|e) upon being shown evidence e for hypothesis H. Note that these rules are markedly non-ampliative, but still allow for our inductive intuitions to be satisfied. This has the benefit of avoiding the problem of induction, but the drawback of not having much of a story about how we get our initial beliefs.

Some argue that since no one is consciously doing said probability math in their heads whenever examining any evidence, it is unfair to hold this as a meaningful picture of rationality. Do you think that is a fair argument? If not, how do we provide a readily applicable concept of Bayesian rationality to ordinary people?

Voluntarism (BvF’s view):

Van Fraassen’s voluntarism attempts to find a comfortable middle ground between these two views in epistemology by introducing our will in the formation of our beliefs. He argues that it is rational to hold beliefs that extend beyond evidence (use ampliative inferences) but he does not hold that beliefs that extend beyond evidence are rationally obligatory. Rather he believes that they are permissible, so, by our will, we may believe them. 

BvF defines four epistemic principles to lay out exactly how his view differs from the others.

  1. There can be no independent justification to continue to believe what we already find ourselves believing
  2. It is irrational to maintain unjustified opinions
  3. There can be no independent justification for any ampliative extrapolation of the evidence plus previous opinion to the future
  4. It is irrational to extrapolate ampliatively without justification

Belief in all four of these is tantamount to skepticism, since it says that we need to justify our beliefs but cannot justify our initial beliefs, nor can we justify extending our beliefs from our prior, irrational beliefs. Bayesians avoid this by denying premise 2. Since Bayesians do not concern themselves with justification, they can sustain having credences and changing them (according to evidence) without needing a story for what justifies them initially. Van Fraassen goes another step and also denies the need for justification for extrapolation (he rejects premise 2 and 4). Thus, van Fraassen believes that we are neither rationally obligated to justify our initial beliefs, nor are we rationally obligated to contitionalize our beliefs on the evidence. 

Now, not just any belief is permissible, but note the important distinction between rationality deciding what one can believe as opposed to what one must believe. The bounds for what one can believe are provided by three items. (1) Prior opinion (2) logical and synchronic (not diachronic!) coherence (3) does not a priori preclude the possibility of vindication.

Logical but nonetheless Irrational: Psillos’ arguments against Bayesianism

Before getting into Psillos’ arguments against voluntarism. Let’s note his argument for why Bayesianism leaves much to be desired for a theory of rationality.

  1. Bayesians believe that our initial beliefs need not be justified by evidence, only that they must be responsive to evidence so that credences can be recalculated
  2. It is irrational to believe a claim without evidence
  3. Bayesians are being irrational when accepting a new belief

What Psillos gets at with this argument is that the strict non-ampliative nature of Bayesianism leaves a gap in explanation for how and why one would go about acquiring new beliefs or deciding that a new piece of evidence is worth considering. He makes the example that there is a lot of evidence that the earth is round, and a little evidence that the earth is flat. Yet, one could, without transgressing any Bayesian rules of rationality, ignore all of the former and believe that the earth is flat. 

Is this a problem for the Bayesian? Can rationality only refer to how our beliefs hang together, or must it make reference to the content of our beliefs? In other words, can it be the case that any belief is rational so long as it is in the right context?

Saving the bacon or burning it? Psillos’ arguments against van Fraassen

Focusing on the third item with regard to how rationality bounds the range of possible beliefs, van Fraassen argues that our beliefs are constrained by our prior beliefs. These prior beliefs are sensitive to an external factor, namely truth. That is to say that even though we choose our beliefs, that does not change the fact that some beliefs can be right upon investigating the relevant facts about the world. Psillos argues that van Fraasen’s voluntarism makes the error of ignoring the content of belief, when it is still a necessary consideration for rationality.

  1. Some beliefs are decidably true or false and likely to be false upon investigation
  2. It is irrational to hold beliefs that, upon checking, are likely to be false
  3. Some beliefs are irrational to hold, regardless of other beliefs
This argument is a bit strange to me (and may be an incorrect reading) as it seems like it is no different from the call for synchronic coherence. Premise two is doing a lot of work by declaring the belief in question to be likely to be false. If we already believe that the belief is likely to be false, would we not be susceptible to a Dutch Book argument? This argument seems to assume that we can know beforehand how likely it is that a belief can be vindicated.

Psillos next argues that BvF’s view does not have an adequate story about how evidence can be incorporated into one’s belief-corpus.

  1. Having true beliefs aids us in our goals
  2. Not pursuing our goals is irrational
  3. Evidence aids in our ability to have true beliefs
  4. It is irrational to not conditionalize on evidence
We may say that it is unwise to not pursue our goals, but is it correct to say that it is irrational?

Psillos then defends IBE against an argument that van Fraassen provides. Van Fraassen argues that if one uses IBE they are susceptible to a Dutch Book situation, since they are providing an unfair probability bonus to a hypothesis H because it satisfies the “best” criterion, which may not necessarily connect to the probability of H being true. 

Psillos argues that one does not run into this problem if they apply IBE consistently before and after learning that H is the best explanation. 

Lastly, Psillos argues that BvF’s voluntarism permits obvious cases of irrationality. Namely…

  1. Cases where one disregards evidence that pertains to the truth or falsity of their beliefs.
  2. Cases where one changes between two permissible beliefs for arbitrarily reasons
  3. Cases where one could refute their own belief with another one of their beliefs
Are these cases irrational? Who gets to decide which evidence pertains to their beliefs? Who gets to decide which reasons are arbitrary? 

Chakravartty: Week 1

Chakravartty (2017, Ch. 1, 2018)

Chakravartty pitches voluntarism as a response to the scientific realism debates. In particular, he sees voluntaristism as an explanation (and potential escape) from the seeming intractability of the scientific realism debates.

Background: The Scientific Realism Debates

Chakravartty offers voluntarism as a framework for diagnosing the seeming intractability of debates about scientific realism. In the philosophy of science, scientific realism is understood as a doctrine consisting of three claims:

  1. A metaphysical/ontological claim: The physical world exists independently of our minds.
  2. A semantic claim: Scientific theories should be interpreted literally, not as “secretly” being only about observable reality.
  3. An epistemological claim: Our best scientific theories provide approximately true descriptions of both observable and unobservable reality.

Antirealists deny at least one of these claims. Chakravartty focuses on those antirealists who deny either the semantic or epistemological claim. Critics of the semantic claim include deflationary views which “recast the study of what things exist, and what they are like, in terms of something else” (2017, 9), and instrumentalists, i.e., empiricists who “hold that scientific descriptions of unobservable things… are meaningless, strictly speaking” (2017, 17).

Most of the debate in the last fifty years or so concerns the epistemological thesis. Chakravartty focuses on constructive empiricism, which is typically taken to deny only the epistemological thesis. Specifically, constructive empiricists hold that our best scientific theories only provide approximately true descriptions of observable reality but are not (or at least need not be) accurate with respect to unobservable reality.

            The most prominent argument for the epistemological thesis is what is called the No Miracles Argument:

NM1. Science is empirically successful.

NM2.  The best explanation of science’s empirical success is that its best scientific theories provide approximately true descriptions of unobservable reality.

NM3.  For all x and y, if x best explains y and y is true, then (probably) x is also true.

SR.     So (probably) our best scientific theories provide approximately true descriptions of both observable and unobservable reality, i.e., the realist’s epistemological claim is true.

The most prominent argument against the epistemological thesis is what is called the Pessimistic Induction:

PI1.    Our best scientific theories in the past have turned out not to provide approximately true descriptions of unobservable reality.

not-SR.   So (probably) our best scientific theories in the present do not provide approximately true descriptions of both observable and unobservable reality, i.e., the realist’s epistemological claim is false.

Evaluate the No Miracles Argument and the Pessimistic Induction. Which premises do you accept and which do you reject?

Scientific Realism Debates’ Inevitability

One might think that scientific realism debates are misguided. After all, what better guide can we have to knowing whether our scientific theories provide accurate descriptions of the world than from science itself? Chakravartty (2017, 31) argues that “scientific ontology is underdetermined by the sciences and case studies thereof.” Reviewing three prominent kinds of scientific realism—explanationist, entity, and structural—he shows that while attention to scientific practice is necessary for adjudicating between different philosophical positions, it is not sufficient. In each of these cases, further philosophical argumentation about historical interpretation (for all three realist positions), language (in the case of entity realism), and structure (in the case of structural realism) is needed.

Do only realist positions face these problems? Chakravartty does not say much on this front.

Scientific Realism Debates’ Intractability

So, it appears that philosophical issues cannot be avoided. Why think these debates are intractable or irresolvable? After all, many philosophical debates are “perennial.” Chakravartty (2018) offers three reasons for this intractability (2018, 226). First, in addition to the “ground-level” disagreement—between, say, the realist’s epistemological claim and its empiricist counterpart—there are also differences in meta-philosophical commitments or “epistemic stances.” Second, these stances “concern how these ground-level positions, realism and antirealism, are formulated as views about scientific knowledge and how they are evaluated.” Third, whether realism or antirealism is correct is decidable only after one has adopted a particular stance. So, the debate bottoms out in these meta-philosophical differences in stances. If this is correct, then arguments such as the No Miracles Argument and Pessimistic Induction cannot possibly resolve the debate, since they aren’t resolving the different stances that are the true drivers of the debate.

Epistemic Stances

So, what exactly are stances? After reviewing some options, Chakravartty settles on the idea that stances are “epistemic policies… regarding which principles and methodologies are appropriate or inappropriate to producing knowledge” (227). Thus, epistemic stances bear directly on the debate about realism’s epistemological thesis.

            Chakravartty (2018, 229) considers three stances: the metaphysical, empiricist, and deflationary stances. For purposes of illustration, let’s consider the first:

The Metaphysical Stance:

M1      Accept demands for explanation in terms of things underlying the unobservable.

M2      Attempt to answer these demands by theorizing about the unobservable.

It is clear why realists, many of whom adopt the metaphysical stance, are drawn to the No Miracles Argument: that argument presupposes M1 and M2. By contrast, neither empiricists nor deflationists share the metaphysical stance’s epistemic policy regarding demands for explanation, so we can now see why they are unmoved by the No Miracles Argument.

            Furthermore, as M1 and M2 illustrate, epistemic policies are not descriptions that can be true or false. Rather, they are imperatives. This goes some way to accounting for the realism debates’ intractability. It is not altogether clear how one argues that one of these imperatives is better than another without begging the question. Following van Fraassen (2002), Chakravartty identifies two criteria of assessment. First, stances should not admit of “self-sabotage by one’s own lights,” meaning that an epistemic policy should not undermine the achievement of the very epistemic aims one seeks to fulfill. This is how van Fraassen and Chakravartty conceive of rationality. Second, one’s stance should reflect what one values epistemically.

Both of these aspects of stances are permissive, meaning that they allow for a multiplicity of rational stances. For instance, the metaphysical stance reflects a commitment to the rationality or epistemic value of accepting certain kinds of explanation, while the empiricist stance does not. Yet, both of these two stances are immune to self-sabotage and reflect their proponents’ core epistemic values, so both realists and empiricist stances seem legitimate.

As Chakravartty notes, some people find these constraints on stances to be too permissive. What do you think?


To be a voluntarist about x is to claim that x can be freely chosen. In epistemology, the controversial doctrine is voluntarism about beliefs. In short, many (if not all) of our beliefs do not seem to be things that we can directly control. (Think, for example, of your beliefs about what you see.) However, voluntarism about stances seems more plausible.

            Chakravartty then notes that one can rationally choose a stance by: (i) surveying the range of stances that are rational, i.e., non-self-sabotaging and (ii) adopting the stance that best accords with one’s epistemic values. From this he notes, “minimally, one can say that a good choice of stance is one that incorporates these two aspects, a negligent choice is one that neglects one or both, and a poor choice is one that for reasons of mistaken assessment or negligence results in the adoption of a stance that fails to pass the test of rationality or value matching” (2018, 234).

Is it really necessary for stances to be voluntarily chosen, or is it enough that different stances are permissible? What’s gained by the voluntaristic move?

Chakravartty, Anjan. 2017. Scientific ontology : integrating naturalized metaphysics and voluntarist epistemology. Oxford: Oxford University Press.

Chakravartty, Anjan. 2018. “Realism, Antirealism, Epistemic Stances, and Voluntarism.” In The Routledge Handbook of Scientific Realism, edited by Juha Saatsi, 225-236. Routledge.

van Fraassen, Bas C. 2002. The empirical stance. New Haven: Yale University Press.