De revolutionibus orbium coelestium divided into six "books" (sections or parts), following closely the layout of Ptolemy's "Almagest" which it updated and replaced: Copernicus argued that the universe comprised eight spheres. The outermost consisted of motionless, fixed stars, with the Sun motionless at the center. The known planets revolved about the Sun, each in its own sphere, in the order: Mercury, Venus, Earth, Mars, Jupiter, Saturn. The Moon, however, revolved in its sphere around the Earth. What appeared to be the daily revolution of the Sun and fixed stars around the Earth was actually the Earth's daily rotation on its own axis. Copernicus adhered
Christianity in the 16th century the Reformed church in Geneva, which became an "unofficial capital" of Reformed Christianity in the second half of the 16th century. He exerted a remarkable amount of authority in the city and over the city council, such that he has (rather ignominiously) been called a "Protestant pope." Calvin established an eldership together with a consistory, where pastors and the elders established matters of religious discipline for the Genevan population. Calvin's theology is best known for his doctrine of (double) predestination, which held that God had, from all eternity, providentially foreordained who would be saved (the elect) and likewise who would