---
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: "budding"
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). Laudan's own 1981 words were CONFIRMED AT PRIMARY 2026-11-03 (promotion of 10-inbox/raw/2026-11-02-read-the-lewis-2001-synthese-and-laudan-1981.md, claude-sonnet-5): read at p. 35 of the typeset original via a JSTOR-digitized scan mirrored on a Simon Fraser University course page (sha dfdc7438…), byte-for-byte identical (normalized for whitespace) to the Magnus & Callender reproduction this note previously relied on. The [unverified-secondhand-quote] flag on Laudan's sentence is LIFTED. Devitt (1984) and McMullin (1984), credited by Psillos as the objection's originators, remain unread at primary — that is now this note's weakest remaining link, tracked as a further lead, not a formal flag, since the representativeness-challenge claim itself already clears the Tier-2 capture-verified floor via Psillos's direct synthesis. Moved seedling → budding on this basis."
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://coursys.sfu.ca/2015fa-phil-880-g1/pages/laudan/view"
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_venue_2: "Larry Laudan, \"A Confutation of Convergent Realism,\" Philosophy of Science, vol. 48, no. 1 (University of Chicago Press, on behalf of the Philosophy of Science Association, 1981), pp. 19–49, at p. 35 — the published venue of record. JSTOR's own article page (jstor.org/stable/187066) is a known-blocked route for this vault's tooling (Cloudflare 'Client Challenge', per 00-meta/specs/sources.md); read instead via a JSTOR-digitized scan reproduced on a Simon Fraser University graduate-course page (coursys.sfu.ca), an unauthorized full-text mirror of the identical typeset pages (allowed per sources.md, Cali ruling 2026-10-01), running JSTOR headers and footers intact. Supersedes the Magnus & Callender 2004 reproduction (fecundity.com, sha 481be91f…) this note previously cited for the same sentence — see Correction history."
source_url_3: "https://coursys.sfu.ca/2015fa-phil-880-g1/pages/laudan/view"
source_quote_3: "the crystalline spheres of ancient and medieval astronomy; -the humoral theory of medicine; - the effluvial theory of static electricity; -'catastrophist' geology, with its commitment to a universal (Noachian) deluge; - the phlogiston theory of chemistry; -the caloric theory of heat; -the vibratory theory of heat; -the vital force theories of physiology; -the electromagnetic aether; -the optical aether; -the theory of circular inertia; -theories of spontaneous generation."
source_venue_3: "Same primary and venue as source_2, at p. 33 — Laudan's own twelve-item list of non-referring successful theories, additions to the subtle-fluids/aethers family discussed earlier in the paper."
source_sha: "bf9999aeb32606dbd5ca9a1221747050a94ddb3dd621646f4d49b401a5d0e156"
source_sha_2: "dfdc7438f30834fa139bb3dde64fd3054a7209a2cbca19f821ffac3160e74d59"
source_sha_3: "dfdc7438f30834fa139bb3dde64fd3054a7209a2cbca19f821ffac3160e74d59"
source_tier: 2
source_tier_2: 1
source_tier_3: 1
independent_roots: 2
root_shared: "source_url_2 and source_url_3 are the same primary (Laudan 1981, read via the SFU mirror), different pages (p. 35 quote; p. 33 list) — one root, not two. Devitt (1984) and McMullin (1984) are credited by Psillos as the objection's originators but remain unread; Psillos 1999 is the second, independent root."
provenance: "Promotion from 10-inbox/raw/2026-10-25-has-anyone-applied-a-formal-survivorship-bias-correction.md, 2026-10-31 (headless); corrected via promotion of 10-inbox/raw/2026-11-02-read-the-lewis-2001-synthese-and-laudan-1981.md, 2026-11-03 (headless)"
origin: "batch"
derived_from: "10-inbox/raw/2026-10-25-has-anyone-applied-a-formal-survivorship-bias-correction.md; 10-inbox/raw/2026-11-02-read-the-lewis-2001-synthese-and-laudan-1981.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"]
seek_code_commit: "d40ee39"
quote_sweep: "PASS 2026-11-01 — source_quote verbatim (normalized) in the capture-time archive (sha256 bf9999aeb326…) [reading-order], same-night model-free sweep"
verified_verbatim: "2026-11-02 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
---


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 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."
Read at primary (p. 35), that sentence is confirmed word-for-word. The catalog
behind it, read at p. 33, is a twelve-item list — crystalline spheres, humoral
medicine, the effluvial theory of static electricity, catastrophist geology's
Noachian deluge, phlogiston, the caloric and vibratory theories of heat, vital-force
physiology, the electromagnetic and optical aethers, circular inertia, and
spontaneous generation — larger than the five-item compression ("crystalline
spheres, humoral medicine, phlogiston, the caloric theory of heat, the optical
and electromagnetic ethers") commonly reproduced downstream, including in an
earlier draft of this note. 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
budding: the representativeness-challenge wording is read directly in a scanned
mirror of Psillos (Tier 2), and Laudan's own 1981 sentence and list are now read
directly at primary (Tier 1); 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

**Correction history.**
- 2026-11-03 (claude-sonnet-5, promotion of
  [[10-inbox/raw/2026-11-02-read-the-lewis-2001-synthese-and-laudan-1981]]) —
  Laudan's own 1981 sentence, previously read only secondhand via Magnus &
  Callender's reproduction, was confirmed verbatim at its own primary venue
  (p. 35 of the typeset original, via a JSTOR-digitized scan on an SFU course
  page). The `[unverified-secondhand-quote]` flag on that quote is lifted. The
  same primary read also showed the catalog behind the quote (p. 33) is a
  twelve-item list, not the five-item compression this note's body previously
  named — the body above is corrected accordingly; the note's core claim (that
  the list's representativeness was challenged) is unaffected. Devitt (1984)
  and McMullin (1984) remain unread at primary — see
  [[00-meta/seek-flags.md]] 2026-11-03 [watch] entry.