My son, I do not say these are foals and those asses, these little monkeys and those great baboons, as you would have me do. As I told you from the first, I regard them as earth's heroes. But I do not wish to believe them without cause, nor to accept those propositions whose antitheses (as you must have understood if you are not both blind and deaf) are so compellingly true.

I beg you, reject antiquity, tradition, faith, and authority! Let us begin anew by doubting everything we assume has been proven!

Make then your forecasts, my lords Astrologers, with your slavish physicians, by means of those astrolabes with which you seek to discern the fantastic nine moving spheres; in these you finally imprison your own minds, so that you appear to me but as parrots in a cage, while I watch you dancing up and down, turning and hopping within those circles.

Magicians can do more by means of faith than physicians by the truth.

All things are in the Universe, and the universe is in all things: we in it, and it in us; in this way everything concurs in a perfect unity.

In space there are countless constellations, suns and planets; we see only the suns because they give light; the planets remain invisible, for they are small and dark. There are also numberless earths circling around their suns.

I pray you, magnificent Sir, do not trouble yourself to return to us, but await our coming to you.