Here we have a powerful and elegant argument to quiet the doubts of those who calmly accepted that the planets revolve around the Sun in the Copernican system, are so disturbed to have the Moon alone revolve around the Earth while accompanying it in an annual revolution about the Sun, that they hold that this structure of the universe should be rejected as impossible. But now we have not just one planet revolving around another; our eyes show us four stars that wander around Jupiter as does the Moon around the earth, and that all together they trace out a great circle around the Sun in the space of 12 years.
Opere, I, 95; Drake trans.