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

So, Fabricius, I already have this: that the most true path of the planet [Mars] is an ellipse, which Dürer also calls an oval, or certainly so close to an ellipse that the difference is insensible.

We do not ask for what useful purpose the birds do sing, for song is their pleasure since they were created for singing. Similarly, we ought not to ask why the human mind troubles to fathom the secrets of the heavens.

The roads by which men arrive at their insights into celestial matters seem to me almost as worthy of wonder as those matters in themselves.

So long as the mother, Ignorance, lives, it is not safe for Science the offspring, to divulge the hidden causes of things.

[God] is the kind Creator who brought forth nature out of nothing.

As soon as somebody demonstrates the art of flying, settlers from our species of man will not be lacking on the moon and Jupiter... Given ships or sails adapted to the breezes of heaven, there will be those who will not shrink from even that vast expanse.