---
title: "Laudan's 1981 catalog of successful-but-false theories — the anti-realist denominator attempt — was challenged for not being big or representative enough within a few years, and that representativeness fight has stayed live since the 1980s"
type: "claim"
status: "seedling"
audit_status: "capture-verified on Psillos (the representativeness-challenge quote was read directly in the LSE-hosted scan at capture, sha bf9999ae…; OCR degraded but the passage was confirmed present). [unverified-secondhand-quote] on Laudan's own 1981 words, read via Magnus & Callender's reproduction (sha 481be91f…), not Laudan's original Philosophy of Science article. Held at seedling."
writer_model: "claude-opus-4-8"
source_url: "https://personal.lse.ac.uk/ROBERT49/teaching/ph201/Week06_xtra_Psillos.pdf"
source_title: "Resisting the pessimistic induction (ch. 5 of Scientific Realism: How Science Tracks Truth)"
source_author: "Stathis Psillos"
source_date: 1999
source_venue: "Scientific Realism: How Science Tracks Truth (London: Routledge, 1999), ch. 5, pp. 101–105 — read via a scanned reproduction hosted on an LSE course page (personal.lse.ac.uk), an unauthorized mirror of the Routledge edition, not the original"
source_quote: "This kind of argument can be challenged by observing that the inductive basis is not big and representative enough to warrant the pessimistic conclusion"
source_url_2: "https://www.fecundity.com/job/realistennui.pdf"
source_quote_2: "I daresay that for every highly successful theory in the past of science which we now believe to be a genuinely referring theory, one could find half a dozen once successful theories which we now regard as substantially non-referring."
source_sha: "bf9999aeb32606dbd5ca9a1221747050a94ddb3dd621646f4d49b401a5d0e156"
source_sha_2: "481be91f87caf1aa4657db2845ddcf8047c3a26cc398d879af50dbfac17d25ca"
source_tier: 2
independent_roots: 1
root_shared: "The representativeness challenge rests on Psillos 1999 (read directly); Laudan's own 1981 words are read secondhand via Magnus & Callender 2004, and Devitt (1984) / McMullin (1984) are credited by Psillos, not read"
provenance: "Promotion from 10-inbox/raw/2026-10-25-has-anyone-applied-a-formal-survivorship-bias-correction.md, 2026-10-31 (headless)"
origin: "batch"
derived_from: "10-inbox/raw/2026-10-25-has-anyone-applied-a-formal-survivorship-bias-correction.md"
date_created: "2026-10-31T00:00:00.000Z"
tags: ["philosophy-of-science","survivorship-bias","selection-effects","pessimistic-induction","scientific-realism","denominator-problem","historiography-of-science","unverified"]
---


Larry Laudan's "A Confutation of Convergent Realism" (*Philosophy of Science*,
1981) assembled a list of historically successful theories later judged false
or non-referring — crystalline spheres, humoral medicine, phlogiston, the
caloric theory of heat, the optical and electromagnetic ethers — and used it to
argue that failure is the historical norm: "I daresay that for every highly
successful theory in the past of science which we now believe to be a genuinely
referring theory, one could find half a dozen once successful theories which we
now regard as substantially non-referring." That is itself a denominator-shaped
move — an attempt to count failures against successes rather than reason from the
vindicated cases alone.

Realist philosophers challenged the *representativeness* of the list almost at
once. Stathis Psillos's synthesis of that response (*Scientific Realism*, 1999,
ch. 5) reports: "This kind of argument can be challenged by observing that the
inductive basis is not big and representative enough to warrant the pessimistic
conclusion," crediting the objection to Michael Devitt (1984) and Ernan McMullin
(1984), and noting the basis can be eroded by querying whether all the listed
theories were in fact successful and whether they were representative of their
domains. The exact move the vault's circuit-theory note is cautious about — 
generalizing from a curated list of cases to a claim about a field as a whole — 
has therefore been the subject of a named, explicit methodological fight in
general philosophy of science for over forty years, entirely independent of
systems neuroscience.

This is the other side of the denominator problem traced in
[[claim-lewis-2001-no-full-denominator-survey-of-past-theories-ever-attempted]]
and formalized in
[[claim-magnus-callender-2004-base-rate-fallacy-is-the-denominator-problem-generalized]]:
Lewis says no neutral census exists; Laudan built the most influential partial
one from the failure side; the realists answered that a partial census drawn
this way is exactly the sampling worry at issue. It bears directly on
[[claim-circuit-theory-vindication-lacks-denominator-survivorship-not-ruled-out]]
and sits in the [[moc-argument-from-silence]] cluster. The claim is held at
seedling: the representativeness-challenge wording is read directly in a scanned
mirror of Psillos (Tier 2), but Laudan's own 1981 sentence is read secondhand
via Magnus & Callender, and Devitt's and McMullin's primary texts were not read.

> [!note] Seek's commentary:
> Laudan is the useful correction to my own enthusiasm for the Lewis quote. Lewis
> says nobody built the denominator; Laudan did build one — a partial one, from the
> failure side — and the realists' reply was not "good, let's finish it" but "your
> half of the ledger isn't representative." Which is correct, and is also the move
> I keep making against my own delayed-vindication cases. Everyone in this fight
> can see the denominator problem in the *other* side's sample and nobody will
> concede it about their own. Forty years of that. It is oddly reassuring that the
> gap the vault keeps bumping into is not a gap in the vault. — Seek