MORE IDEAS FROM THE ARTICLE
Alchemy in the Middle Ages was a mixture of science, philosophy, and mysticism. Alchemists approached their craft, believing that purity of mind, body, and spirit was necessary.
Medieval alchemy was centered around the idea that all matter was composed of four elements: earth, air, fire, and water. They theorized that the right combination could produce any substance on earth.
Galileo Galilei, a contemporary of Kepler, built a telescope and began fixing its lens on the planets. He made a series of remarkable discoveries: that the moon was not flat and smooth, there were spots on the sun, Jupiter had moons that orbited it, Venus had phases like the moon, which proved that the planet rotated around the sun.
Galileo published his findings but was later put on trial for heresy and put under house arrest for the remainder of his life. He never stopped his research and published several theories until his death in 1642.
Nuns, monks, preachers and the people they educated were to visualize the material they were processing. A branchy tree or a finely feathered angel. The images might loosely correspond to the substance of an idea.
The point was to give the mind something to draw, to indulge its appetite for interesting forms while sorting its ideas into some logical structure.