The first is a commonplace. By combining analysis with experimentation-by combining theorizing with systematic observation of natural phenomena-men like Gali­leo and Newton launched an intellectual revolution and helped to usher in our modern age of science. Not only did they dis­cover truths about the physical world that continue to be rele­vant and important, but they also developed new methods of studying nature that have proved to be of wide usefulness in many areas of study and research.

Commonplacing, florilegia, anthologies, miscellanies, zettelkasten are such a fascinating tradition. They make a lovely ratchet for thinking.

This priority list, which was added to deal with the mess the notes became after a few weeks, turned out to be important. It was a ratchet—whenever we happened on a good train of thought, the priority list ensured that we would not drift back down to a lower-quality conversation path.