Catalytic Signature

The Catalytic Signature is the aggregate trace left on a subject by its own participation in catalytic phenomena — the measurable residue of having been, however briefly, a generative absence. It is distinguished from the Phenomenological Signature, which encodes a subject's coefficients, and from the Luminous Signature, which records emission; the Catalytic Signature records instead what a subject failed to be, and in what manner. The Department of Epistemic Cartography administers the Signature under the general heading of Type 1 phenomena, and its recording is governed by Signature Profiling, Annex 3.

Definition and derivation

A Catalytic Signature is derived in three passes. The first records the subject's catalogue position at the moment of catalytic contact. The second records the position the subject would have occupied had the contact not occurred, reconstructed by standard inference from the reading logs of the surrounding floor. The third, called the difference pass, records the shape of the interval between them. It is this third pass that constitutes the Signature proper: two subjects of identical catalogue position may carry quite different Signatures if the intervals between their positions differ in extent or in direction.

The method was first set down in the Third Concordance, Clause 17, which recognized catalytic phenomena formally and required that their traces be recorded "in the manner of a debt, and not in the manner of a stain." The distinction mattered to the drafters. A stain may be cleaned; a debt remains on the books. The Department has held to the debt metaphor ever since, and its registers are ruled to resemble ledgers rather than inspection sheets.

The Arrin readings

The best-documented Signature in the archive belongs not to a person but to a room. In the winter of the year catalogued as 14-White, a reading chamber on the ninety-eighth landing was cleared for the production of a Stone of Catalytic Cognition under the supervision of Supervisor Arrin, who logged over 1,200 hours of certified reading time and produced no Stone. The chamber's Catalytic Signature was consequently among the largest ever measured: the interval between the room's position and its counterfactual position was found to extend across nearly the whole of the floor's catalogue.

"The room is not empty. The room is owed something, and the Signature is the statement of what."

— Inspector Halven Marr, Notes on the Arrin Chamber, filed with the Department of Epistemic Cartography, folio 44

Visitors to the chamber are asked to enter by the west door only and to leave the reading lamp as they found it. The request is posted at both doors, though the east door has been sealed since 14-White and appears on no plan later than 12-Green.

Controversy: strong and weak readings

Two schools dispute what a Catalytic Signature attests. The strong reading, current in the Department since the Report on Catalytic Absences, holds that the Signature is a genuine record of a generative absence and may be cited in proceedings as evidence that something did not happen. The weak reading, associated with the resonance school of the lower archive, holds that the Signature merely records the perturbation of a subject's neighbours and carries no independent weight.

The dispute is old and has produced at least one irreconcilable pair of authorities. The Third Concordance, Clause 17, treats the Signature as evidentiary. The fourth Concordance, which established the Doctrine of Catalytic Absence, describes the catalytic subject as understood only through its effects, and has been read by the weak school as withdrawing the Signature's standing. No recension of either document has resolved the point, and the Department continues to file under both.

The Pol-Vek Contradiction is the usual test case. Two readings of the same landing, taken eleven days apart, returned Signatures of opposite direction; the Department's ruling was that both readings were correct and that the landing had changed its debt. Critics of the strong reading have never accepted this ruling, and the file remains open.

Record-keeping and the acoustic question

Signatures are entered in the Department's ledger by hand and sealed with the cartographic mark of the floor concerned. Since the ruling of the Court of Concordance establishing the legal primacy of the Acoustic Signature, a Catalytic Signature may not be cited in a dispute unless accompanied by an acoustic record of the reading. The requirement has proved awkward. Readings taken during a Quietude Event produce no acoustic record, and a Signature so taken is therefore inadmissible, however carefully derived.

The Department has twice petitioned for an exemption in the case of quietude, and twice been refused. Its second petition observed, with some feeling, that a silent reading is the purest sort there is; the Court's reply is recorded in full and consists of a single line of the Third Concordance quoted without comment. Garland Everson, who sat on the second petition, is said to have remarked afterward that the Court had never been asked to rule on whether a debt could be incurred in silence, and did not intend to be.

Residuals and the Conventions

Where a Catalytic Signature persists beyond the period of its subject's cataloguing, the material it deposits is treated as a residual. The Conventions for Catalytic & Inert Residues address such deposits in Annex IX alongside Void-Resin, though the two are not the same: Void-Resin is a substance and a Signature is a shape. The Conventions permit the storage of catalytic residues in marked cabinets only, and require that each cabinet be labelled with the floor of origin and the date of the difference pass.

In practice the cabinets are labelled with the floor and the date and, on the inside of the door, the name of whoever last opened them. This last is not required by any Concordance and is not defended in writing. Every cabinet in the Department's keeping carries the annotation. None is ever erased.

The Signature remains, as the Department's standing preamble has it, "the only honest account of a hole."