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Galileo GalileiLetter to the Grand Duchess Christina
Nonfiction | Essay / Speech | Adult | Published in 1615A modern alternative to SparkNotes and CliffsNotes, SuperSummary offers high-quality Study Guides with detailed chapter summaries and analysis of major themes, characters, and more.
Key FiguresCharacter Analysis
Galileo Galilei
Galileo Galilei is one of the central figures of the 17th century’s Scientific Revolution and of the history of science as a whole. He was an astronomer, physicist, engineer, and inventor. His many discoveries include the four largest moons of Jupiter (now commonly called the “Galilean moons”), the phases of Venus, the mountains on our Moon, and the rings of Saturn. He also invented the telescope he used to make these discoveries.
He also made significant discoveries in mechanical physics. He determined that objects of different weights fall at the same speed. He also conducted many experiments with pendulums and discovered that a pendulum has the same period (the time it takes to return to where it started) regardless of its amplitude (how high or low it starts). Galileo conducted physical experiments, recorded what he observed, and drew conclusions from those observations. In his “Letter,” he ardently defends direct observation and extrapolating theories from facts.
He was born in Pisa, Italy, in 1564. He studied mathematics and worked as a private tutor before becoming the chair of mathematics at the University of Padua. In Padua, he published his first scientific treatises and soon became a member of the Duke of Florence’s court. He wrote a letter about Copernicus to his student Benedetto Castelli, which he then expanded into the letter to Duchess Christina. Because of the “Letter” and his defense of Copernicus more broadly, Galileo was called before the Inquisition—an organization that combatted heresy within the Catholic Church. He published more treatises, including his Dialogue Concerning The Two Chief World Systems about the Ptolemaic and Copernican theories. This book led to another audience with the Inquisition, and Galileo was convicted of heresy. He was sentenced to house arrest and died at his home in Arcetri in 1642.
Grand Duchess of Tuscany, Christina of Lorraine
Christina was born in Nancy, France, in 1565, one year after Galileo. She died in Florence in 1637. She was the mother of Galileo’s patron, Cosimo II de Medici, as well as the great-granddaughter of Catherine de Medici. Her son Cosimo was only 19 when he became duke, which gave Christina an outsized influence at court. She was both devoutly religious and well educated, with a particular interest in theology. Her opinions and interests had notable political influence.
In late 1613, Christina held a dinner party at which she expressed concern about Galileo’s support of Copernicus. She wondered how the heliocentric model could be compatible with scripture. Although Galileo wasn’t at the party, his friend Benedetto Castelli was; he told Galileo about the duchess’s comments. Galileo first wrote a letter to Castelli in response and then wrote an expanded letter addressed directly to the duchess.
St. Augustine
Augustine of Hippo was born in 354 CE in what is now Souk Ahras, Algeria, and died in Hippo (now Annabia, Algeria) in 430. He adapted Greek and Roman thought, particularly Platonism, into a Christian context. He also developed the Christian doctrine of original sin, which holds that all human beings are born into a state of moral evil.
Roman Catholicism recognizes Augustine as a doctor of the church, which gives his writings special authority. He was and remains widely influential. His Confessions, an autobiographical and religious treatise, is still read today. His ideas about biblical exegesis are relevant to Galileo’s “Letter.” Augustine argues that the Christian church has a specific scope and duty, to understand the word of God and help people achieve salvation. Understanding matters such as whether the sky “is fixed or moved” is not within the realm of religion (Paragraph 12). He wrote that to understand the physical universe “would require many subtle and profound reasonings [...] but to undertake this and discuss it is consistent neither with my leisure nor with the duty of those whom I desire to instruct in essential matters more directly conducing to their salvation and to the benefit of the holy Church” (Paragraph 12). Galileo makes this distinction a cornerstone of his argument.
Nicolaus Copernicus
Nicolaus Copernicus was born in 1473 CE in Toruń, Poland. He was a polymath and a devout Catholic, much like Galileo a century later. His uncle, Lucas Watzenrode, was prince-bishop of Warmia (a region of Poland) and helped the young Copernicus after both his parents died. Copernicus was educated at the University of Krakow, which had an excellent astronomy and mathematics department, and helped his uncle with his religious and political duties. Copernicus developed the theory of heliocentrism.
He published his theory in two different books. The first, his Commentariolus, is a brief sketch of his ideas, while the second, De revolutionibus, is his definitive work on the subject. Copernicus circulated Commentariolus only among his friends. Scholars have debated how many copies of De revolutionibus he sold. Regardless of how widely read his books were, Copernicus’s ideas spread and became both controversial and influential.
