Continuity Is Not an Archive

In a long-inhabited city, a new sewer trench can cut through the foundations of an older house. The drainage improves while the earlier neighborhood becomes harder to reconstruct.

Maintenance can erase historical evidence by replacing arrangements that no longer serve the present. Nothing has to go wrong for evidence to disappear. What matters to a historian may be precisely what no longer matters to the functioning system. An abandoned settlement escapes that particular pressure. Some arrangements survive because nobody needs them to do a new job.

An obsolete software fork can preserve distinctions that years of improvement have removed from the maintained version. Two components once kept separate may have been merged; an exception may have vanished when the problem it handled ceased to matter. The discarded code can reveal what earlier builders had to accommodate. It need not be a better program to be a useful historical document.

A complete version history can preserve those distinctions too. But that is because someone kept a record, not because the current program needs those arrangements to run. Recordkeeping allows the past to remain available without requiring it to remain operational.

Abandonment is not a reliable archive. Roofs collapse; storage fails. Survival alone does not establish former importance. An outlying settlement need not resemble the former center; an experimental fork need not represent the main line of development. A remnant can establish that an arrangement existed without establishing that it was typical. It may preserve an intermediate state, not a beginning.

Reconstructing earlier states from the current version alone can make today's arrangement look older than it is. Later adaptations can appear to be longstanding features; discarded alternatives disappear from the account. The result of repeated changes can be mistaken for evidence that little ever changed.

Continuity of use is not continuity of evidence.