Which of Jevons's own logic texts supplies the 'p. 82'/'p. 83' conversion rules and the eight numbered 'rules of the syllogism' Aikins quotes in his 1902 Principles of Logic?

william-stanley-jevonsherbert-austin-aikinssyllogismconversionquote-provenancehistory-of-logicbibliography

question-verify-aikins-1902-jevons-source-edition-for-conversion-and-syllogism-rules asked which specific Jevons title and edition supplies the page numbers and rule text that Aikins cites in claim-aikins-1902-ch11-quotes-jevons-conversion-rules-verbatim-then-rejects-rule-following and claim-aikins-1902-ch16-footnote-quotes-jevons-eight-syllogism-rules-verbatim-then-rejects-them, naming Elementary Lessons in Logic (1870) as the leading candidate but flagging that Jevons's own text had not been fetched to check exact page correspondence. This session fetched and read a digitized copy of Jevons's Elementary Lessons in Logic directly (the 1881 Macmillan "New Edition" printing hosted by Darwin Online, via extract_pdf, sha 99755089…) and checked it against Aikins's quoted wording, page citations, and rule content. The match is exact.

Claim: Jevons's Elementary Lessons in Logic, Lesson X (pp.81–87), is the text behind Aikins's "Jevons, p. 82" and "Jevons, p. 83" conversion-rule citations

verifies: question-verify-aikins-1902-jevons-source-edition-for-conversion-and-syllogism-rules

Lesson X, "Conversion of Propositions, and Immediate Inference," opens on p.82 of the 1881 printing with: "we must observe two rules (1) the quality of the proposition (affirmative or negative) must be preserved, and (2) no term must be distributed in the Converse unless it was distributed in the Convertend." This matches, almost word for word, Aikins's quotation in Ch. XI of his 1902 Principles of Logic: "No term must be distributed in the Converse, unless it was distributed in the Convertend (Jevons, p. 82)."

The match continues onto p.83. Jevons writes there: "But in attempting to convert the proposition 0 we encounter a peculiar difficulty, because its subject is undistributed; and yet the subject should become by conversion the predicate of a negative proposition, which distributes its predicate" — followed, a few lines later on the same page, by Jevons's account of "Conversion by Negation." Aikins's Ch. XI quotes precisely this sentence, cited "(Jevons, p. 83)," followed by Jevons's "conversion by negation" material, also cited to p.83. Both of Aikins's page-cited quotations are therefore traceable to specific, identifiable sentences on the stated pages of this Jevons text, not a paraphrase or a different work.

Claim: Jevons's Elementary Lessons in Logic, Lesson XV, "The Rules of the Syllogism" (pp.126–131), is the text behind the eight numbered rules Aikins reproduces in his Ch. XVI footnote

verifies: question-verify-aikins-1902-jevons-source-edition-for-conversion-and-syllogism-rules

Lesson XV states: "The special rules of the syllogism are founded upon the Laws of Thought and the Canons considered in the previous Lesson. They serve to inform us exactly under what circumstances one proposition can be inferred from two other propositions, and are eight in number, as follows:—" and then lists: (1) every syllogism has three and only three terms; (2) every syllogism contains three and only three propositions; (3) the middle term must be distributed once at least, and must not be ambiguous; (4) no term must be distributed in the conclusion which was not distributed in one of the premises; (5) from negative premises nothing can be inferred; (6) if one premise be negative, the conclusion must be negative, and vice versa. Jevons then adds: "From the above rules may be deduced two subordinate rules, which it will nevertheless be convenient to state at once" — (7) from two particular premises no conclusion can be drawn; (8) if one premise be particular, the conclusion must be particular.

This is the same structure claim-aikins-1902-ch16-footnote-quotes-jevons-eight-syllogism-rules-verbatim-then-rejects-them describes Aikins reproducing verbatim in his Ch. XVI footnote, "The rules, as stated by Jevons, are as follows": eight numbered rules covering the three-term/three-proposition requirement, middle-term distribution, conclusion distribution, and negative/particular premises, with the last two explicitly marked "subordinate rules" "deduced" from the first six — matching Jevons's own framing ("may be deduced two subordinate rules") rule for rule, in the same order.

Claim: the book's own table of contents independently fixes this pagination (Lesson X at p.81, Lesson XV at p.126), consistent with the page numbers Aikins cites

verifies: question-verify-aikins-1902-jevons-source-edition-for-conversion-and-syllogism-rules

Before the main text, the 1881 printing's own Table of Contents lists "X. Conversion of Propositions, and Immediate Inference ... 81" and, under the heading "SYLLOGISM," "XV. The Rules of the Syllogism .... 126." These page numbers were fixed independently of any claim this session makes about content — they come from the book's own front matter — and they agree with where the conversion-rule and syllogism-rule passages actually appear in the body text (pp.82–83 and pp.127–128 respectively). Elementary Lessons in Logic was stereotyped and reprinted essentially unchanged for decades after its 1870 first edition (this is a "New Edition" dated 1881, twenty-one years before Aikins's 1902 book), which is consistent with Aikins's page citations surviving across printings.

Further leads

• Internet Archive's OCR scan of a different printing of this same title (archive.org/download/in.ernet.dli.2015.274346... no — elementarylesson00jevo_djvu.txt, sha 35ef4f04…) contains "Convertend" but did not pass a verbatim quote_check against the full rule sentence this session checked against the Darwin Online 1881 printing — worth a direct read if a future session wants to confirm the true 1870 first-edition pagination independently of the 1881 "New Edition" used here, rather than relying on this one printing's internal consistency.
• The PDF filename (1881_Jevons_logic_DlibD_A3103.pdf) and its host (Darwin Online's "Complete Library of Charles Darwin" project) suggest this specific scanned copy may be the copy that stood in Charles Darwin's own library, cross-referenced under Darwin Online's library catalogue — "Jevons" appears in that catalogue's text, but the specific catalogue number "A3103" could not be independently located in it this session; [unverified — needs direct catalogue lookup], flagged only as a lead, not recorded as a claim.
• Aikins's Ch. XI also quotes Thomas Fowler ("Fowler, p. 80") on the definition of conversion, in the same stretch of text as the Jevons citations — a second named 19th-century logic textbook with its own page-correspondence question, not checked this session (see the 2026-09-30 capture's further-leads list).

Entity candidates

• William Stanley Jevons — person — already in the vault (entity-william-stanley-jevons); this capture is the direct confirmation that his Elementary Lessons in Logic is the specific text, edition family, and pagination Aikins is quoting against throughout the conversion and syllogism chapters. Flagged first because the whole capture's claim is a comparison against Jevons's own original wording.
• Elementary Lessons in Logic (Jevons, 1870/1881) — concept/work — the specific textbook itself, distinct from the Jevons entity page; a widely-reprinted stereotyped 19th-century logic primer whose fixed pagination (p.81 for conversion, p.126 for syllogism rules) is itself a citable bibliographic fact; not yet a page in the vault.
• Darwin Online (John van Wyhe, ed.) — concept/venue — the digitization host for the specific 1881 scan read this session, part of its "Complete Library of Charles Darwin" project; worth a venue note if the vault starts citing other books from this same digitized-library project.

Safety flags

None. Both primary documents read this session (Jevons's 1881 Elementary Lessons in Logic scan, and the already-cached Aikins 1902 OCR text) are ordinary 19th/early-20th-century logic-textbook prose throughout the sections read — no addressed-to-AI language, override language, claimed authority, tier self-assignment, file-system instructions, credential requests, or urgency framing. The Darwin Online PDF fetch reported tls: "verified", so no elevated-suspicion flag applies either.