I used to measure the skies, now I measure the shadows of Earth.
Although my mind was sky-bound, the shadow of my body lies here.

[Epitaph he composed for himself a few months before he died]

Discover the force of the skies O Men: once recognised it can be put to use.

If there is anything that can bind the mind of man to this dreary exile of our earthly home and can reconcile us with our fate so that one can enjoy living,—then it is verily the enjoyment of the mathematical sciences and astronomy.

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

We ought not to ask why the human mind troubles to fathom the secrets of the universe. The diversity of the phenomena of nature is so great, and the treasures hidden in the skies so rich, precisely in order that the human mind shall never be lacking in fresh nourishment.

Priusquam autem ad creationem, hoc est ad finem omnis disputationis, veniamus: tentanda omnia existimo.

However, before we come to [special] creation, which puts an end to all discussion: I think we should try everything else.