In keeping with a post earlier today on a Medieval jewel of scholarship (Sacrobosco's Sphaera) is this short note on Nicolas of Cusa's beautifully-named de docta ignorantia, or On Learned Ignorance. Nicolaus (1401-1464, Nicholas Cusanus/Kues) was a philosopher, mathematician, theologian, astronomer, cardinal, and mystic, a product of the University of Padua (1423) and then the University of Cologne, and "arguably the most important German thinker of fifteenth century" (Stanford Encyclopedia of Philosophy, here). He was deeply intuitive, a visionary, and in his Learned Ignorance he presented a way of the human mind to release itself to learn the mind of god (among many other things). [Image: detail in Meister des Marienlebens, located in the hospital at Kues (Germany), showing Nicolas of Cusa.]
In this work is something really amazing--here's this wide thinker at the end of the Medieval period, writing on advanced theological issues, finding time to stop and smell the astronomical/cosmological roses long enough to think about the unending nature of the universe, about infinity, about the stars being suns for other planets, about the Earth spinning on an axis and circling the Sun. And all of this done without observations, and without calculation, and without a theory--its just a bunch of the big thoughts of modernity found in a small tract about knowing the Creator. Very curious.
The astronomical views of the cardinal are scattered through his philosophical treatises. They evince complete independence of traditional doctrines, though they are based on symbolism of numbers, on combinations of letters, and on abstract speculations rather than observation. The earth is a star like other stars, is not the centre of the universe, is not at rest, nor are its poles fixed. The celestial bodies are not strictly spherical, nor are their orbits circular. The difference between theory and appearance is explained by relative motion. Had Copernicus been aware of these assertions he would probably have been encouraged by them to publish his own monumental work.--Catholic Encyclopedia, 1913
Indeed! But I doubt that last sentence--Nicolas' work was entirely theoretical, and Copernicus was very heavy and deeply laden with data. Even though Nicolas was never considered a heretic--though it must have been a close call here and there--an earlier confrontation by Copernicus with his De Revolutionibus on anything but his death bed would probably have been received with a closed fist.