Principle of Sympathetic Resonance

Definition and first formulation

The Principle of Sympathetic Resonance is the general rule governing the agreement between a floor and what is shelved upon it. It is catalogued under the administrative class Foundation Resonance and is treated by the Sympathetic School as the master principle from which all catalogued phenomena of the same family descend. In its shortest recorded form, taken from the second recension of the principle's own text, it reads: "A floor shall be presumed to agree with its contents until measurement shows otherwise" (The Principle of Sympathetic Resonance, second recension, §12).

The formulation is administrative rather than physical. It does not assert that floors and contents agree; it asserts that they are to be presumed to agree, and it places the burden of disturbing that presumption on whoever holds a measuring instrument. Nearly every dispute in the principle's long history turns on this distinction, and most of them turn on it badly.

The principle admits a reciprocal form, which is what the engines are built to detect: a floor may modify its contents as readily as the contents modify the floor. Annex 2 of the second recension extends the presumption to both directions and notes, without further comment, that the reciprocal case "has never been satisfactorily observed, and is retained for completeness."

Measurement and instrumentation

Observation of the principle is the ordinary business of the Resonance Technicians' Guild, whose field instruments — chiefly the Sympathetic Resonance Engine and the older Sympathetic Resonator — are calibrated before each survey with dusted Sympathetic Stone. Calibration is the part most often skipped in practice; a Guild circular of 4 Cassian 1188 records that three of the seven survey parties dispatched that season had calibrated against the wrong end of the stairs, and that their readings were consequently off by a constant factor the circular declines to name.

Floor readings of this kind are filed under Sympathetic Floor Resonance (I/S-450.00.σ). The filing is not straightforward. Readings taken during the winter quiet, when few readers are moving, tend to disagree with readings taken during the autumn influx, and the reconciliation procedure requires a third survey at a season unnamed in the schedule, which no party has yet been dispatched to perform.

"Where a floor returns a resonance not exceeding the presumption, no further work is required. Where it returns a resonance exceeding the presumption, the presumption is amended in the appropriate annex, and the reading is filed without further work."

— Harmonic Resonance Protocols, Protocol 11

Protocol 11 has been read aloud at every Guild assembly since its adoption and has never been understood in the same way twice.

Application in cataloguing

The principle underwrites a number of practical operations, several of which would otherwise have no justification at all. Sympathetic resonance is recorded as the foundational theory of the engines used for scanning and recalibration, and the principle is invoked whenever a shelf is to be shifted, a floor renumbered, or a reading room subdivided. It is likewise the stated basis of Resonance Mapping and of the selection rules governing the Resonance Shelves, where a volume placed on sympathetic ground is permitted to remain until it is found to disagree with it.

Where the principle has been misapplied, the record is candid. On the 14th of the winter month in the year the archive records as 1191, a clerk named Halven Rusk undertook to renumber a storage floor on the ground that the floor had clearly failed to agree with the salt ledgers stored there since before his appointment. Rusk's reasoning was that the ledgers had gone unconsulted for eleven years and the floor had done nothing to stop them. The survey he submitted in support of the renumbering was taken with an uncalibrated instrument borrowed from a neighbouring floor, and the renumbering was struck by the Concordance on Floor Numbering on the technical point that Rusk had numbered the floor twice, in opposite directions, nine days apart. Rusk's subsequent memorial — a document of some forty pages, of which thirty-one concern the personal conduct of the survey party's instrument-bearer — is preserved in the annex but is not, and has never been, considered.

Disagreement among the Concordances

The principle's authority rests on an unstable footing, and the archive does not disguise it. The Third Concordance, Annex 4, holds that the presumption applies only to floors that have been formally named, on the reasoning that an unnamed floor has nothing to agree with. The Fourth Concordance, which was produced in the same decade and circulated in preference to the third, holds at §7 that the presumption applies to all numbered floors "whether named or no", and adds that the third's position is "a convenience of clerks".

The contradiction has never been resolved. The Concordance on Concordance, a document of considerable age and uncertain authorship, provides at clause 6 that where two Concordances disagree the more recent governs, and at clause 9 that where two Concordances disagree the older governs, "the older being nearer to the original agreement." Both clauses are printed on the same page of every authorised recension. The Sympathetic Floor Index applies the third for floors with names of three parts or more and the fourth for the remainder, a practice that has never been challenged in writing and which nobody defends aloud.

A further dispute concerns the status of Sympathetic Residue: the fourth recension treats residue as falling under the presumption, while the Harmonic Resonance Protocols treat it as an exception to be recorded separately. The two positions have been reconciled once, in 1204, by the expedient of recording every case in both places, which remains the standing practice.

Academic reception

The Sympathetic School maintains the principle's primacy, on grounds set out at length in its own recension and summarised in the School's admissions address as "the only rule the Tower has ever had that could be checked". Critics within the Resonance Technicians' Guild allow the principle's usefulness for filing and dispute its reach, noting that Bibliographic Resonance, which the School treats as a special case of the principle, has never once been measured below the presumption's limit in a season of heavy consultation.

The current consensus, if it may be called that, is procedural: the principle is presumed correct wherever it is invoked, and any party who invokes it is expected to have a calibrated instrument, a completed survey, and a Concordance open to a page that supports their position. Parties who have all three are rarely asked to produce them. Parties who have two are asked to produce the third, and it is here that most of the archive's litigation lives.

Visiting readers are reminded that the presumption does not extend to the visitor. Instruments must be left with the attendant, and the stairs are locked at the ninth bell.