Aikins's silence on Jevons's Logic Piano is weak on McGrew's *record* term, not *notice* — the mirror image of Isaacs's P-257 silence, and a third failure mode for the hub

argument-from-silencemcgrewherbert-austin-aikinswilliam-stanley-jevonslogic-pianohistoriographymethodology

moc-argument-from-silence grades the vault's negative-citation findings on McGrew (2013)'s product of three probabilities: whether the author would have noticed the fact (N), recorded it (R), and whether the record would have survived (S). Survival is not in question here: Aikins's 1902 book survives and its text has been read (claim-aikins-1902-index-and-full-text-omit-machine-boole-piano-mechanical — whose capture carries known OCR gaps, bounded there; they qualify the sweep's coverage, not the survival term).

Notice is comparatively strong: Aikins demonstrably read Jevons's Elementary Lessons in Logic closely enough to cite two of its lessons to the page, in the same stereotyped edition that contains the Logic Piano passage sixty to seventy pages later in the same volume (claim-jevons-elementary-lessons-lesson-xxiii-describes-logic-piano-and-its-royal-society-debut) — a far stronger notice condition than a document never opened. What is weak is record: Aikins's specific project in the chapters that cite Jevons, per his own Preface, is to replace Jevons's stated syllogism and conversion rules with his own principles (claim-aikins-1902-preface-states-program-of-replacing-jevons-style-syllogism-rules-with-principles) — a project keyed to one thematic block of Jevons's book (claim-aikins-engagement-with-jevons-tracks-traditional-syllogism-block-not-booles-system-block), giving him no argumentative occasion to invoke a different block's topic, however rhetorically useful the machine might have been as a literal illustration of "mechanical" rule-following.

This is a mirror image, not a repeat, of Isaacs's P-257 silence, the hub's first instance weak on notice: there, the document never had occasion to generate the relevant record at all. Here, notice is strong and the generated record simply had no occasion to touch this topic — a different term, and a different reason for the same low product.