Dialogue Concerning the Two Chief World Systems

Lord Filippo Salviati came there from Florence; in him, the least of his splendors were his noble blood and the magnificence of his riches. He possessed a sublime intellect, which fed upon no delight more greedily than upon exquisite speculations. With these two, I often found myself discussing these matters, alongside a Peripatetic Philosopher <note original: "Filosofo Peripatetico">A follower of Aristotle's school of philosophy, so named for the peripatos or covered walkways in Athens where the philosopher and his students walked while teaching. who believed that nothing hindered the understanding of truth more than the fame one acquired through traditional Aristotelian interpretations <note original: "interpretazioni Aristoteliche">The standard academic readings of the works of the Greek philosopher Aristotle, which dominated the universities of the time..

Now, since a most bitter death has—in the brightest prime of their lives—deprived Venice and Florence of those two great lights, I have resolved to extend their fame through these writings of mine, as far as my weak powers allow, by introducing them as the speakers in this present controversy. Nor shall the good Peripatetic lack his place; because of his excessive affection for the commentaries of Simplicius <note original: "Simplicio">A 6th-century Neoplatonist commentator on Aristotle. Galileo uses this name for his fictional Aristotelian character, likely as a pun on the Italian word for "simpleton" (semplice)., it seemed appropriate to allow him the name of that revered author, while keeping his own name hidden. May those two great souls, forever venerable to my heart, accept this public monument of my undying love; and through the memory of their eloquence, may they help me explain these promised speculations to posterity.

As often happens, various fragmented discussions had occurred by chance between these gentlemen, which had served more to ignite than to satisfy the thirst for learning in their minds. Therefore, they made the wise resolution to meet for several days to come, during which, setting aside all other business, they would devote themselves to contemplating—through more orderly inquiry—the wonders of God in the Heavens and on the Earth. The gathering took place at the Palace of the Most Illustrious Sagredo <note original: "Illustrissimo Sagredo">Giovanni Francesco Sagredo (1571–1620), a Venetian nobleman and close friend of Galileo, who acts as the host and the open-minded listener in the book.; after the required, but brief, pleasantries, Lord Salviati began in this manner.