Tenet of Non-Accretion

The Tenet of Non-Accretion is a custodial principle of the Custodial Protocols asserting that no matter may be added to, removed from, or permitted to settle upon a catalogued structure once it has been entered in the Floor Register. First articulated in the Seventeenth Recension, Annex 9, it is the principal doctrinal counterweight to Spontaneous Lithic Accretion, and the reason that phenomenon is classified as unsanctioned rather than merely unusual. The Tenet governs roughly eleven thousand structures in the upper archive; its scope below Floor 300 has never been settled.

Formulation

The Tenet appears in the Seventeenth Recension as a single sentence, which the Bureau of Doctrinal Consistency has declined to gloss:

"A structure once registered is complete, and completion admits of no further addition, however small, however slow."

— Concordance of the Seventeenth Recension, Annex 9, clause 1

The drafting clerk, Armeno Vesh, appended a marginal note that has since acquired the force of law in three separate recensions: "however small includes dust." Vesh's note was written in the winter of 3402, after a lint problem in the Register vaults on Floor 62 that occupied four months and two sub-committees. It remains the most-cited marginal note in the custodial corpus.

Application and the Weeping Staircase

The Tenet's most consequential test came with the mineral accumulation on the Western Helical Staircase between Floors 43 and 46. The Weeping Staircase was at that time a registered structure, entered in the Floor Register under the designation WHS-43/46. When accretion was first reported, the Office of Structural Custody found itself in an unresolvable position: the Tenet forbade removal of the deposit, and the deposit was, by definition, an addition to a registered structure. The Office assigned the difficulty to Librarian Ordinate Selv in 3611. Selv's ruling was that the Weeping Staircase had "accreted past the point at which it may be considered the structure originally registered," and recommended re-registration rather than removal.

The ruling was accepted with the proviso — inserted by the Bureau, over Selv's objection — that no re-registration may occur while accretion is ongoing, "lest the Register be made to chase its own subject." Consequently the Weeping Staircase has remained unregistered since 3611, a status its custodians describe as "provisional in perpetuity."

Conflict with the Selvage Principle

The Tenet stands in open contradiction with the Selvage Principle, which holds that a structure's margin of tolerance for adjacent matter is to be judged by the structure itself rather than by the Register. The Concordance of the Nineteenth Recension attempted to reconcile them in Annex 4, declaring that the Tenet "applies to additions and not to adjacencies," and that the distinction was to be determined case by case by the Bureau of Doctrinal Consistency. The Bureau has heard forty-one such cases in six hundred years and has published reasons in nine.

The matter was further complicated by Referential Sprawl: since the Tenet is cited by structures it does not govern, its authority now extends, by citation, to matters the Seventeenth Recension never contemplated. The Bureau's standing instruction is that citation does not create application, but the instruction is itself uncited.

Exceptions

Three exceptions are recognised. The first concerns the Archive-Grade Neutral Substrate of Floor 0, which is held to be non-accreting by nature and therefore outside the Tenet's reach. The second concerns the Accretion of the Unwritten, which the Gallery of Unwritten Prefaces maintains is a documentary rather than a material phenomenon and thus not an addition to anything. The third, introduced by the Thirtieth Concordance, permits the controlled removal of matter where the Office of Structural Custody has certified that the matter is "not of the structure and not of the Tower." No such certificate has ever been issued in full; twelve have been issued with reservations, all twelve concerning mould.

Criticism

Critics of the Tenet — chiefly the Continualists, who hold that the Tower is a process rather than a collection — argue that a principle forbidding addition to a completed structure cannot coexist with a structure that is itself never complete. The Tenet of Administrative Inertia is frequently invoked in reply: where the Tenet is ambiguous, inaction is correct and further amendment is unnecessary. The Bureau has adopted this position without formally endorsing it.

In 3988 the Sub-Committee on Marginal Matter proposed a four-word amendment inserting "or may have been" after "complete." The amendment has been tabled annually since. It is not expected to pass. Visitors to registered structures are asked not to bring dust with them.