Replied to Monks, a polymath and an invention made by two people at the same time. It’s all in the history of the index by Aaron Davis (Read Write Collect)

Anna Kelsey-Sugg and Julie Street discuss Dennis Duncan research in the index. He explains how the practice evolved separately in Paris and Oxford during 1230. Although the two inventions were not connected, they were both associated with the rise of the university and the lecture. In the early 13th...

Great find Aaron. Thanks for the ping.

I’ve gone back further than this for the commonplace and the florilegium which helped to influence their creation, though I’ve not delved into the specific invention or general use of indices in the space heavily. I suspected that they grew out of the tradition of using headwords, though I’m not sure that indices became more popular until the paper by John Locke in 1689 (in French) or 1706 (in English).

I’ll put Dr. Duncan’s book into the hopper and see what he’s got to say on the topic.