Galileo and Sagredo are looking through his telescope at the moon. Sagredo struggles to understand what he’s seeing, because he’s been taught all of his life that the moon is a dim star. Through the telescope, however, it appears to have mountains and plains. Sagredo refuses to believe Galileo’s explanations, and he warns Galileo once again, this time mentioning Giordano Bruno, who was recently burned at the stake for advancing heretical astronomical views.
Galileo, however, continues. He says that there is “no difference” between Heaven and Earth and that this day would go down in history as the day that man “got rid of heaven.”
This quote appears to be an invention of Brecht’s and not a quote from Galileo himself.
Mrs. Sarti interrupts the two men to introduce the Procurator. He has arrived to tell Galileo the shocking news that the telescope wasn’t an original invention. A Dutch merchant has just arrived and is unloading an entire shipment of them as they speak. The Procurator is indignant—he says Galileo has made him the laughingstock of the city—but Galileo shrugs off the Procurator’s concerns. He’s convinced, if nothing else, that the star charts he’ll be able to create with the device will more than compensate for his lies about inventing it, since they will give captains the ability to navigate the ocean by the stars. Enraged, the Procurator storms off, slamming the door.
Galileo is absolutely right about the value of the star charts. While the Procurator is upset about Galileo’s deception, he has no real reason to doubt him about it. He knows that Galileo has invented remarkably useful things in the past. This moment, however, highlights a third consideration that weighs Galileo down. In addition to concerns about money and persecution, he must also worry about how his work will affect the reputation of his superiors.
Sagredo asks if Galileo knew about the Dutch telescopes beforehand. Galileo confirms that he did, but also that he didn’t care. He did improve on them, he says, and at any rate he absolutely had to have the money. Even with the extra money, he still has debts he can’t pay.
Galileo’s debts appear occasionally throughout the play. He likes the finer things in life: good food, good wine, and rare books. Mostly this predilection for finery just serves as a kind of comic relief.
The two men return to the telescope, though Sagredo admits that he’s scared to see what else Galileo will show him. They look at the moons of Jupiter (which he calls stars) and discover that one’s missing. The only possible explanation is that the moon has gone behind the planet. But for this to be possible, it would somehow have to have punctured the crystal sphere that holds Jupiter. Galileo becomes extremely excited by their discovery and declares loudly that Copernicus was right—there were no spheres. He calls for Andrea, while Sagredo tries to quiet him, telling him to think more slowly and calmly. Sagredo warns him that even if what they’ve discovered is true (which he believes it is), the discovery will create a lot of trouble for Galileo.
It’s easy for the audience to side with Galileo, because history (and science) has proven him correct. By showing Galileo’s mania here in contrast to Sagredo’s measured call for level-headedness, however, Brecht hopes that the audience will consider how the average person might have at first felt about Galileo’s ideas. Those who doubted Galileo in his time weren’t fools, he seems to say, any more than those who doubt communism today are. They were (and are), nevertheless, wrong.
By way of explaining, Sagredo asks Galileo where God is if He’s not in the Heavens, which angers Galileo. Galileo responds that he’s a mathematician, not a theologian. If God lives anywhere, he says, it must be within men. Sagredo contends that Galileo’s profession won’t matter to the Church, who will burn him for a heresy like that. They have, after all, done so to others—and in the not-so-distant past. Galileo replies that those men didn’t have the telescope and so they couldn’t provide the proof that he has. Since people align themselves with reason, and his proof bolsters that reason, Galileo believes that he will be safe. Sagredo, however, says that nothing in his life has ever taught him that people will act the way Galileo expects.
Sagredo’s question doesn’t seem to matter to Galileo, which might call into question Galileo’s Christianity. It shouldn’t. Wherever God exists is beyond Galileo’s ability to prove. Instead, God has given Galileo the ability to prove other things about the universe—things that no one else has yet been able to prove. Galileo is also confident that God gave man reason. Reason, in turn, gave man the ability to understand Galileo’s proofs. Thus Galileo believes that the very way God created man will protect Galileo from persecution.
Still, when Virginia appears moments later, Galileo forbids her from looking through the telescope. He even downplays the invention in front of her, calling it a “flop” that has only helped him to discover some dim stars.
It’s unclear at this point whether Galileo seeks to protect Virginia from the stigma of questioning Church doctrine, or whether he distrusts his own daughter.
Galileo also tells Virginia that he’s written to the Grand Duke of Florence, asking for a job. Sagredo bristles at this, because Florence is run by monks who will not accept Galileo’s attacks on Aristotle’s system. But Galileo says he must have both the money and the time to work on his proofs. He feels confident that he will be able to “drag the monks” to the telescope if he needs to show them the validity of his work. He also plans to sweet talk the Duke by naming the newly discovered stars after the Duke’s family.
Galileo certainly seems very confident about his decision to move to Florence—that is, his words indicate that he’s confident. Brecht offers nothing about how Galileo felt, internally, about this decision. Instead, it’s helpful to imagine how one might feel one’s self if forced to put convictions (even sincerely held ones) to the life-or-death test that Galileo does here.