Geometry is one and eternal shining in the mind of God

I am much occupied with the investigation of the physical causes [of motions in the Solar System]. My aim in this is to show that the celestial machine is to be likened not to a divine organism but rather to a clockwork ... insofar as nearly all the manifold movements are carried out by means of a single, quite simple magnetic force. This physical conception is to be presented through calculation and geometry.

The heavenly motions... are nothing but a continuous song for several voices, perceived not by the ear but by the intellect, a figured music which sets landmarks in the immeasurable flow of time.

I had the intention of becoming a theologian...but now I see how God is, by my endeavors, also glorified in astronomy, for 'the heavens declare the glory of God.'

A mind is accustomed to mathematical deduction, when confronted with the faulty foundations of astrology, resists a long, long time, like an obstinate mule, until compelled by beating and curses to put its foot into that dirty puddle.

Do we ask what profit the little bird hopes for in singing?

The moon... is a mass, akin to the mass of the earth, attracts the waters by a magnetic force, not because they are liquid, but because they possess earthy substance, and so share in the movements of a heavy body.