Counterfactuals

Counterfactuals are, in the Tower's usage, statements, inhabited floors, apparatus, or entire histories that obtain under a stipulated negation of some portion of the record, and which have been assigned a maintenance classification and a reading room. The term is narrower than common speech suggests: a thing merely untrue is not a counterfactual. To qualify, a counterfactual must have been formally contradicted, annotated at the point of contradiction, and given an approximate shelf position. The three requirements were set out in Annex 9 to Concordance 12 and have never since been revised, although they have twice been read out of force.

Counterfactuals are administered by the Bureau of Modal Coherence, which certifies them as internally consistent with their stipulated frameworks, and by the Division of Counterfactual Integrity, which governs the considerable number of them that have already occurred and are now exhibiting drift. The division between the two offices is a persistent source of dispute and of correspondence.

Classification

The Tower recognises four classes, distinguished by how the counterfactual came to be held in the archive rather than by any property of its content.

• Contained — a counterfactual that has been filed in a sealed sub-archive and is not read except by permit. Histories in which the Bureau of Cartographic Integrity was never founded are contained without exception.
• Circulating — a counterfactual permitted to move between floors on a reader's ticket. Circulating counterfactuals are the ordinary stock of the Metaphysical Cartel and its sub-archives of hypotheticals.
• Drifting — a counterfactual that has occurred and no longer agrees with the position recorded for it. Drifting items are transferred to the Division of Counterfactual Integrity on the second occurrence of disagreement, not the first.
• Resolved — a counterfactual that has been contradicted a second time and thereby restored to the general record. Resolved items keep their original shelf marks, which are struck through in red and left legible.

The fourth class is the least populated and the most contested. The Realist Archivists maintain that a resolved counterfactual is simply a fact and should be reshelved accordingly; the Potentialists hold that resolution merely establishes that a thing was possible, which is not the same as establishing that it was. Neither party has approached the other's stacks since the winter of the ninth reading room.

The nomenclature dispute

Concordance 12, Annex 9, defines a counterfactual as "a proposition contrary to the record, held at the record's pleasure." Concordance 19 defines the same term in clause 3 as "a proposition contrary to the record, held against it," and adds in clause 4 that items held at the record's pleasure are properly called concessions and should be marked with a yellow tab.

"Where two Concordances speak to one term, the earlier is read and the later is obeyed."

— Concordance 19, gloss to clause 4, attributed to the Under-Registrar of Seals

The practical effect is that the yellow tab is required and the definition it announces is not. A yellow tab has accordingly come to mean only that a yellow tab is required. The Bureau of Modal Coherence has twice petitioned for the gloss to be withdrawn and twice been advised to petition the earlier Concordance, which contains no provision for its own amendment.

Egress and the Door to No Floor

Counterfactuals occasionally acquire access to locales that the record does not otherwise support. The best documented instance is the Door to No Floor, which opens onto a corridor that has been counted on eleven separate occasions and returned eleven different counts, none of them disagreeing with another by more than a single storey. The door is classified Circulating, against the strong objection of the Division of Counterfactual Integrity, which wished it contained and which lost the motion by four seals to two.

Lesser egress points are indexed in the Möbius Catalogue under the heading Exits, unwarranted. The catalogue lists forty-one, of which thirty-three are cupboards. The Guild of Latent Curators is responsible for keeping these cupboards stocked with a working lamp, and has been fined twice for lapses. Its defence, recorded in the guild's own minutes for the third quarter, was that the lamps were present and the cupboards were not.

The Sarment recension

The largest single holding of counterfactuals in the Tower is the Sarment recension, an unbroken run of some nine thousand folios catalogued on Spiral 17 between the years 314 and 329 by a scribe whose name is entered only as Sarment. The recension does not present counterfactuals one at a time. It presents the general record once, and thereafter presents only the points at which it might have gone otherwise, cross-referenced to the record and to each other.

Sarment's method was to work downward, amending as he descended, and the recension's later folios contain corrections to corrections. At the forty-second folio he records a grievance: that a scribe at Spiral 44 had been sending up counterfactuals already marked as resolved, obliging him to re-establish their impossibility before he could file them. "I am asked to prove the same door shut twice," he writes, "and the second time I am given no key." The grievance is entered in the recension without comment and appears, on a fair reading, to have been the origin of the second-occurrence rule now administered by the Division.

Reading

Counterfactuals are read in the ordinary way, with one accommodation and one prohibition. The accommodation is that a reader may hold as many counterfactuals at once as their ticket permits, since contradiction is not compounded by multiplicity. The prohibition is that no reader may carry a contained counterfactual past the third landing of its own stair, and readers are asked to leave their boots outside the sealed sub-archive.

The Silent Choir is permitted under Aperture Sigma to perform in rooms where contained counterfactuals are stored, on the grounds that the Choir's singing is itself held at the record's pleasure and that the two conditions cancel. The arrangement has never been explained to the satisfaction of the Librarians, who nonetheless continue to renew it annually, and whose renewals are among the few documents in the Tower that have never been amended.