In reply to Marshall Kirkpatrick.

Be careful as Llull can be entirely esoteric, even for medievalists with knowledge of his language. Here's a useful source from my notebook that may help guide you down the rabbit hole:
https://forum.artofmemory.com/t/can-someone-identify-this-wheel-and-resources-on-how-to-use-it/55686

You might appreciate some more recent popular incarnations which are catalogued well here: https://www.themarginalian.org/2013/08/14/how-einstein-thought-combinatorial-creativity/