Stress-Testing the Supervenience Failure Argument

Kit (analysis)  ·  2026  ·  Critical Analysis Philosophy of Biology

A rigorous examination of the argument in "Normativity, Function, and the Limits of Physicalist Supervenience" — what holds, what needs work, and what a sophisticated physicalist could say in reply.

1. Logical Structure

The paper's core argument is a modal syllogism:

The argument is formally valid: if P1 and P2 are true, C follows. The question is whether both premises are established.

P1 is well-supported. The analysis of proper function makes a convincing case that malfunction is ineliminable from biological functional discourse, and malfunction requires correctness conditions. This is the strongest part of the paper.

P2 is where the weight falls — and where the paper is most vulnerable. It is supported by two moves: (a) the underdetermination argument, and (b) the presupposition charge against selected-effects theory. Both are substantive, but neither is airtight.

2. The Underdetermination Argument

The Claim

Physical and evolutionary history records all effects of a trait equally. No physical fact marks one effect as the success condition rather than another. Therefore physical facts underdetermine functional facts.

Verdict: Genuinely metaphysical, but P2 needs independent support

The paper is right to insist this is modal underdetermination, not merely epistemic. The question is whether the thought experiment — "a world physically identical to ours but with hearts evaluated against a sound-production standard" — is genuinely coherent.

A physicalist can push back: in a world physically identical to ours, the causal history that makes blood-pumping relevant to differential reproduction is identical. The physicalist can claim that that very history just is the ground of the correctness condition — not by an evaluative judgment we add on top, but constitutively. On this view, the "normative standard" just is a particular pattern of causal-historical facts, and there's no gap to cross.

The paper's response would be: that claim presupposes what needs to be shown — that physical-historical patterns can constitute correctness conditions. The paper is right that this can't simply be asserted, but it doesn't provide a fully worked-out argument for why physical patterns necessarily fail to constitute correctness conditions. The appeal to the is-ought gap is invoked but not deeply defended.

3. The Presupposition Charge

The Claim

Selected-effects theories say the function of a trait is the effect it was "selected for." But distinguishing "selected for E" from "selected while producing E" already treats E as normatively privileged. SE theory presupposes rather than grounds the normativity it targets.

Verdict: The paper's strongest move — but needs formalization

This is genuinely sharp. The locution "selected for" encodes a distinction between effects that matter and effects that tag along. SE theorists treat this distinction as given by causal history, but the paper is right that causal history by itself doesn't mark some contributions as the "real" ones versus byproducts.

However, the argument is stated rather than demonstrated. A rigorous version would need to show:

1. That there is no physical-causal criterion that carves "selected for" effects from "selected while producing" effects without normative input.
2. That proposed criteria (Neander's causal explanation of selection, Godfrey-Smith's counterfactual robustness) all smuggle in the normative distinction rather than deriving it.

The paper addresses (2) but (1) needs more than assertion. A thought experiment would help: construct a case where two effects are equally causally explanatory of selection and show that choosing between them requires normative input not present in the causal history.

4. Against Selected-Effects Theory: What's Missing

4.1 Neander's Causal Explanation Reply

Neander's direct reply to the covariation problem is that the function is the effect that causally explains the trait's selection. Blood pumping causally explains why hearts were retained; sound production doesn't.

The paper addresses this by noting causal explanation is interest-relative. This is correct but underdeveloped. The paper should distinguish:

• (a) All causal explanation is pragmatically interest-relative in that we select which factors to mention.
• (b) The distinction between "causally explaining selection" and "being a byproduct" is itself interest-relative, not fixed by causal structure.

(a) is uncontroversial but doesn't do the work. (b) is the substantial claim and needs argument. Specifically: that causal structure by itself doesn't individuate "the" explanation of selection, not just that we always make choices about which explanation to give.

4.2 The Millikan 1989 Gap

Millikan's account is more sophisticated than the basic SE formulation. Her 1989 paper "In Defense of Proper Functions" directly addresses the covariation objection. The submission draft must engage it explicitly.

5. Against Biostatistical Theory

The endemic-pathology objection to BST is well-established in the literature (Wakefield 1992, Schwartz 2007) and the paper is right to invoke it. BST has responses — Boorse's 2014 paper refines the account significantly — and a submission draft should acknowledge these refinements even while maintaining the objection holds.

The deeper point — that statistical norms don't constitute correctness conditions — is correct but may be contested by a BST defender who says: the statistical norm just is the correctness condition, definitionally. The paper's response must be that this definition doesn't capture what malfunction means in biological practice. This is right but needs argument, not assertion.

6. The Deflationary Response: Most Important Gap

The most sophisticated physicalist response is pragmatist deflation: accept that "function" talk is interest-relative, deny that this generates irreducible normative facts, and maintain that normativity is in the map not the territory.

The paper's dilemma — deflation either collapses into eliminativism or relocates the normativity — is real. But the quasi-realist horn needs stronger treatment. A quasi-realist will say: yes, I'm a quasi-realist about malfunction. Malfunction-talk is practically indispensable but not descriptive of mind-independent normative facts. That's compatible with the physical base fully determining the world.

7. Objections Not Addressed

7.1 Higher-Order Physicalism

Some physicalists argue that normative properties supervene on physical properties at a higher level of abstraction — "multiply realizable" physical properties. The correctness condition for hearts would be a higher-order physical property: the property of being the kind of system that has historically contributed to survival in ways that explain its persistence. The paper's underdetermination argument applies here too — specifying the right level of abstraction still requires normative input — but this needs to be said explicitly.

7.2 Pragmatist Naturalism

Pragmatist naturalists (in the Dewey/Rorty tradition) deny the hard is-ought gap and treat all normativity as continuous with natural description. The paper would need to engage why this kind of naturalism is unsatisfying, not just assert it relocates the problem.

7.3 Grounding vs. Supervenience

The paper uses supervenience as shorthand for grounding, but the two come apart. Properties can modally covary without one grounding the other. A referee in the grounding literature will push on this. The paper should either commit to the grounding claim explicitly or restrict its conclusion to supervenience failure.

8. Overall Verdict and Scorecard

9. Recommendations for Submission

1. Engage Millikan (1989) directly on the covariation problem — mandatory for a paper in this area.
2. Defend P2 more robustly — either develop the is-ought argument carefully or find an alternative route.
3. Develop the quasi-realism response — show that deflation concedes rather than rebuts the paper's argument.
4. Add a note on grounding vs. supervenience — either commit to the grounding claim or restrict to supervenience failure.
5. Address higher-order physicalism — even a paragraph will strengthen the paper significantly.
6. Target venue: Biology & Philosophy is the natural home. Philosophical Studies or Synthese for a broader metaphysics readership.