In Doug Engelbart’s demo he showed the power of having different views on the same information, such as when he viewed his shopping list by various criteria and then changed the view to a map: https://youtu.be/yJDv-zdhzMY?t=939
I am not sure if I had seen that when I designed a concept for being able to drag text around on the desktop in the mid-90s which I called the System Wide Scratch Area but the idea of putting things out on a space to work on the relationships seems pretty self-evident. We do it as children and my father did it with his documents in his pre-digital workflow.
Joseph Novak, who has of course been invited to the Future of Text Book, formalised concept mapping and Tony Buzan was inspired by this and developed mind mapping. In the 1940s Alex Faickney Osborn introduced brainstorming. Thinking on a surface either with marks straight not he surface or using some kind of cards goes back a long time, at least to Carl Linnaeus during the 1700s.
What I am investigating though is the ‘magic’ of digital representations above the flexibility of thoughts on cards, but there is still a lot to be learnt from cards, at least until we have digital desk sized desktops.