I measured the skies, now the shadows I measure, Sky-bound was the mind, earth-bound the body rests. [Kepler's epitaph]

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

I am stealing the golden vessels of the Egyptians to build a tabernacle to my God from them, far far away from the boundaries of Egypt. If you forgive me, I shall rejoice; if you are enraged with me, I shall bear it. See, I cast the die, and I write the book. Whether it is to be read by the people of the present or of the future makes no difference: let it await its reader for a hundred years, if God himself has stood ready for six thousand years for one to study him.

Eyesight should learn from reason.

O telescope, instrument of much knowledge, more precious than any sceptre!

If this [the Mysterium cosmographicum] is published, others will perhaps make discoveries I might have reserved for myself. But we are all ephemeral creatures (and none more so than I). I have, therefore, for the Glory of God, who wants to be recognized from the book of Nature, that these things may be published as quickly as possible. The more others build on my work the happier I shall be.

Astronomy would not provide me with bread if men did not entertain hopes of reading the future in the heavens.