If the attractive virtue of the moon extends as far as the earth, it follows with greater reason that the attractive virtue of the earth extends as f… - Johannes Kepler

Indeed I reply in a single word to the sentiments of the saints on these questions about nature; in theology, to be sure, the force of authorities is to be weighed, in philosophy, however, that of causes. Therefore, a saint is Lactantius, who denied the rotundity of the earth; a saint is Augustine, who, admitting the rotundity, yet denied the antipodes; worthy of sainthood is the dutiful performance of moderns who, admitting the meagreness of the earth, yet deny its motion. But truth is more saintly for me, who demonstrate by philosophy, without violating my due respect for the doctors of the church, that the earth is both round and inhabited at the antipodes, and of the most despicable size, and finally is moved among the stars.

Nu ne întrebăm în ce scop util cântă păsările, cântecul este bucuria lor de când au fost zămislite pentru cântat. La fel, n-ar trebui să ne întrebăm de ce spiritul omului se străduieşte să pătrundă secretele cerurilor. Diversitatea fenomenelor naturii e atât de mare, iar comorile ascunse în ceruri atât de bogate, tocmai pentru ca spiritul omului să nu fie nicicând lipsit de hrană proaspătă.

Every corporeal substance, so far forth as it is corporeal, has a natural fitness for resting in every place where it may be situated by itself beyond the sphere of influence of a body cognate with it.