Epitome Astronomiae Copernicanae

"[A] comparison was undertaken between this book—or the related work On the Harmonies...—and Aristotles books and Metaphysics... I have nothing to worry about in the case of Aristotle... His Most Serene Highness cannot dislike whatever is the more convincing, whether it be that the world was first made at a fixed beginning in time as was my work On the Harmonies, or will be destroyed at some time, or is merely liable to destruction, like the alterations of the ether and the celestial atmosphere; nor will he ever prefer the Master Aristotle to the truth of which Aristotle was ignorant."

"Aristotle is the man... who in On the Heavens... Chapter 9... asks: "Do the stars give forth sounds which are modulated harmonically? and answers no: ...I grant that no sounds are given forth but I affirm and demonstrate that the movements are modulated according to harmonic proportions."

"Then, as in each and every planet there is a very fast movement and a very slow movement and in a fixed proportion... and... Saturn and Jupiter have middling eccentricities, Mars a great eccentricity, the Sun and Venus slight eccentricities, and Mercury a very great eccentricity... I also brought forward a solution... and I took my solution from the Archetype of the harmonic cosmos: whence it is established that this cosmos cannot be better... and that it is impossible that the world should not have been created at a fixed beginning in time. This attempt of mine... should have been brought forth into the light with strength of mind... the highest confidence in the visible works of God... or at the exhortation of Aristotle himself, who judged that in these questions you should not suppress or be silent about probabilities any more than... certainties."

"Aristotle... in the Metaphysics, Book XII, Chapter 8... built... the most sublime part of his philosophy... concerning the gods... who... sends his students to the astronomers and who defers to the astronomers in respect to their authority and... testitimony...[H]e would never have scorned or... myself, if... necessity... had made us contemporaries. For he orders his students "to read through both,"...[i.e.,] Eudoxus and , for the one had corrected the errors of the other; and today that would be to read both Ptolemy and Tycho: "but to follow" not, he says, the more ancient, but "the more accurate." And so... if the astronomer, using the arguments which modern times have put forward concerning the heavens, has indicated that creatures arose in the heavens and will disappear once more—in opposition to the opinion of him who alleges experience, but experience not sufficiently long."

"As regards the academies, they are... concerned not to have the program of teaching change very often... the things which have to be chosen are not those which are most true but those which are most easy."

"[T]he truth concerning the mutable nature of the heavens can be taught conveniently... [I]t is not without its use in explaining even those parts of the philosophy of Aristotle which are clearly false, as Book VIII of the Physics concerning celestial movement and Book II of On the Heavens concerning the eternity of the heavens—so... a comparison could be made between the philosophy of the gentiles and the truth of Christian dogma."

"Accordingly, if certain subtleties which are difficult to grasp should not be laid before beginners, or if they should not be preferred to the accepted and necessary teachings, it does not follow that... those things should neither be written nor read privately."

"You can count few academies in which it is a part of the program to explain the Metaphysics of Aristotle: yet Aristotle wrote the Metaphysics too, a very useful work..."

"But this kind of argument against Aristotle will perhaps seem too contentious. Therefore let us use his own testimony... for he is not everywhere consistent: in the Metaphysics he attributes movement to the celestial bodies for its own sake and teaches "that they are moved in order that they may be moved"; but in On the Heavens, being admonished by the things themselves, he attributes something... like the terrestrial... multiplex and turbulent to the stars or... their movers, who by... these mechanisms and movements seek another end... in this way... he adduces the fewness of movements in the moon as... the inferior... closer kinship to the Earth."

"[T]he boundary posts of investigation should not be set up in the narrow minds of a few... "The world is a petty thing, unless everyone finds the whole world in that which he is seeking," as Seneca says. ...[T]he boundary posts of true speculation are the same as those of the fabric of the world; but the Christian religion has put up some fences around false speculation... in order that error may not rush headlong but may become... harmless..."

"Antiquity teaches us... how vainly man sets up boundary posts where God has not set them... how severely all the astronomers were blamed by the first Christians. ...Yet today we set up academies everywhere: we order that philosophy be taught, that astronomy be taught, that the antipodes be taught."

"Astronomers should not be granted excessive license to conceive anything they please without reason: on the contrary, it is also necessary for you to establish the probable causes of your Hypotheses which you recommend as the true causes of the Appearances. Hence you must first establish the principles of your Astronomy in a higher science, namely Physics and Metaphysics."