What an Index Reveals About a Document's Intended Use
Launch library · evergreen read
An index, whether attached to a single volume or built for an entire collection, reveals what its compilers expected future readers to search for, which is itself a small but genuine piece of evidence about how a document or collection was actually meant to be used at the time.
A name indexed prominently suggests someone considered significant by the compilers, while a name mentioned in the text but absent from the index can suggest an oversight, a deliberate omission, or simply a lower priority assigned to that particular figure by whoever originally built the index by hand.
Reading an index this way, as evidence in its own right rather than merely a navigation tool, can surface a genuinely useful research question long before a single page of the underlying document has actually been opened and read, simply by noticing what its own compilers apparently expected future researchers to look for first.