34 pages 1 hour read

Discoveries and Opinions of Galileo

Nonfiction | Book | Adult | Published in 1957

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Part 3Chapter Summaries & Analyses

Part 3 Summary: “Letter to the Grand Duchess Christina”

Writing to Christina, the grand duchess of Tuscany, Galileo recalls the controversy his writings in astronomy stirred up some years ago because they contradicted commonly held notions about the physical universe. Some scholars responded by attacking Galileo in print with “vain arguments” backed up with passages from the Bible, “which they had failed to understand properly, and which were ill suited to their purposes” (175). These critics were not merely hostile to Galileo’s discoveries but seemed to harbor a “reckless passion” against Galileo himself, and they enacted “calumnies and persecutions” (176) against him.

Normally, Galileo would simply laugh these incidents off, confident that truth would win out in the end. However, he feels compelled to respond for several reasons. First, his attackers are charging him with religious heresy—something that he finds “abhorrent.” Second, some critics do not understand the science. Third, such attacks could influence public opinion in disfavor of science and mathematics in general and of professionals in these disciplines. Some of Galileo’s opponents even imply that science as such is inimical to religion—something with which Galileo strongly disagrees. In addition, the personal attacks against Galileo are misplaced because he is simply carrying on the thought of Nicholas Copernicus—a scientist who in his day was respected by the Catholic Church and was himself a member of the clergy.

The writings of the early Christian theologian St. Augustine teach us how to preserve the proper relation between knowledge and scripture. Augustine said that we should not jump to the conclusion that a scientific discovery contradicts the Bible. We should exercise “moderation” and caution, because rational inquiry may in time reveal a deeper harmony. Physical observation is as legitimate a source of truth as the Bible. Conclusions drawn from scientific experiment will not contradict the Bible, provided that the latter is correctly understood and interpreted.

Galileo points out that if one were to interpret the Bible always according to the literal sense of the words, one would fall into “grave heresies and follies” (181) such as believing that God has a physical body. This leads Galileo to stake an important claim: When the Bible speaks of physical matters, it often accommodates its language to the capacity and understanding of common people, who lack scientific knowledge. It follows that we should not use the Bible as an authority for physical science; instead, we should use sense experience and reason. In doing so, we are by no means ignoring God, because “the holy Bible and the phenomena of nature proceed alike from the divine Word” (182). God created all things and is revealed in both nature and scripture.

Galileo emphasizes that he does not mean to discount the Bible’s importance. On the contrary, the Bible exists precisely to convey truths that reason and science can never reach. Moreover, knowledge of science and physical laws can help us interpret the Bible correctly. Galileo even holds that the Bible is preferable as an authority—even in “propositions which are not matters of faith”—because “divine wisdom surpasses all human judgment and conjecture” (183).

However, since God endowed us with “senses, reason, and intellect” (183), He must desire us to use them. Unless He were a deceiver, God would not require us to deny what our faculties tell us. Many areas of physical science (e.g., the stars and planets) are not even mentioned in the Bible, even though the biblical authors would have been aware of them. Therefore, the Bible’s purpose cannot be to teach physical science. The Bible treats only subjects that are relevant to salvation; it teaches “how one goes to heaven,” not “how heaven goes” (186).

Consequently, one cannot use the Bible as a weapon to attack scientific theories. Heresy applies to theological and moral ideas, not scientific ones. Religion does not require one to take this or that position on a purely scientific question.

God is the author of all truth, and both reason and revelation lead us to truth. Therefore, it is important that theologians find the “true senses” of biblical texts. Such interpretations will accord with what we know through reason and science. Theologians frequently disagree, however, and scripture itself says that endless “disputations” are a result of original sin. Thus, in matters that do not directly concern salvation, one should not close the path of free inquiry because of what one scriptural interpretation may say. Galileo suggests putting measures in place to prevent “shallow and vulgar” writers from misinterpreting scripture to their own purposes and thereby misleading readers.

Although theology is the “queen of the sciences,” theologians should listen to and learn from the subordinate sciences as well. Further, Galileo insists that we define clearly what we mean when we say that theology is “queen of sciences.” Theology has this status because of its subject’s dignity, not because it includes within itself the subjects and content of the other sciences. It is thus unjust and risky for theologians to make pronouncements on nontheological matters.

Galileo makes a plea to theologians to be aware of the difference between “doctrines subject to proof” and “those subject to opinion” (194). Scientific theories fall in the first category. A scientist cannot simply change his views at whim, because they are based on logical proof drawn from the observation of nature. Early theologians such as Augustine recognized this.

This leads Galileo to stake another important claim. Among the statements made by physical scientists, some are merely asserted and others are “soundly demonstrated.” If a scientific statement falls into the first category, “anything contrary to the Bible involved [in it] must be held undoubtedly false and should be proved so by every possible means” (194). However, if a scientific statement falls into the second category, then it is the duty of the theologian to show that the Bible does not contradict it.

Those who believe that a scientific teaching is false must show that it has not been “rigorously demonstrated”—and not merely use the Bible as proof against it. This approach will act as a check against faulty reasoning by scientists.

Next, Galileo looks at specific instances in the Bible that have been cited as being at odds with science. He reiterates the principle that both science and scripture are true, and two truths cannot contradict each other. In matters that surpass human reason, we must have faith in the Bible’s teachings. Conversely, in matters of physical science, we should trust competent and well-demonstrated conclusions drawn from observation. If an apparent contradiction exists between this and scripture, then the theologian must inquire further to find the true sense of the biblical text, which may not be a literalistic sense.

Galileo provides some examples. The Bible speaks of the heavens as being flat like a curtain, whereas science shows them to be spherical. The Bible speaks of the sun rising and setting, whereas Copernicus showed that the earth moves around the sun. In using such expressions, the Bible accommodates its language to the way we see things every day, not to the way they are in scientific fact.

Galileo stakes one final claim: Just because the Bible and church fathers agree in a certain position does not mean that it must be held as true, unless they also condemned the contrary position. It may have been only an assumption, not something consciously “analyzed and determined” (203). Certain questions, such as whether the earth moves, did not even become important issues until relatively recently. Ultimately, physical conclusions are not matters of faith.

Part 3 Analysis

Between 1613 (the year of “Letters on Sunspots”) and 1615 (the year of the “Letter to the Grand Duchess Christina”), increasing concern about Galileo’s ideas arose among some theologians. The purpose of Galileo’s “Letter to the Grand Duchess Christina” was to give a full statement of his position on the proper relationship between science and religion. He stated that a desire to “justify myself in the eyes of all men” (179) on questions of faith.

The addressee of the letter was Christina of Lorraine, the Grand Duchess of Tuscany. The mother of Grand Duke Cosimo II (the dedicatee of “The Starry Messenger”), Christina was highly educated, a devout Catholic, and keenly interested in science.

Galileo is clear about his own position and the precise goals of the letter. On the side of science, he reaffirms his belief in the Copernican system. On the side of religion, he emphasizes his own personal faith as a Catholic—his desire to protect the integrity of religion and to maintain the Bible’s “majesty, dignity, and authority” in “a holy zeal for the truth” (205). In addition, Galileo shows due deference for theologians and spokespeople for the church in general, saying that he respects their judgment about faith.

Galileo is prudent and circumspect about what he wants to achieve in the letter. Acknowledging that theology is not his area of expertise, he says that he means to “submit myself freely and renounce any errors into which I may fall in this discourse through ignorance of matters pertaining to religion” (180). He even states that if anything he says offends religious truth, then “let my book be torn and burnt, as I neither intend nor pretend to gain from it any fruit that is not pious and Catholic” (181).

Galileo’s targets in the letter are certain theologians who misunderstand scripture and the nature of science. Galileo believes that these critics are doing damage to faith and the Bible as well as to reason and science. He suggests that his opponents are aware of the weakness of their position and thus turn to scripture as a weapon because “feeling unable to stand up against the assaults of the adversary, they seek ways of holding him off” (209).

Such critics stumble because they fail to understand the complementary and symbiotic nature of science and faith. Indeed, both science and scripture express different aspects of truth. Thus, to censure true science is no less than to censure truth itself. It is self-contradictory because the Bible itself says that the greatness of God is read “in the open book of heaven” (196)—a powerful metaphor for the religious dimension of astronomy.

On Pages 211-215, Galileo discusses Joshua 10, a biblical passage that figured prominently in clerical opposition to heliocentrism. In this story, the sun is said to have miraculously stood still for a whole day. Galileo attempts a reinterpretation of the story in terms of the Copernican system, arguing that it makes better sense under this system than in the Ptolemaic system. Here, Galileo shows his serious intentions as both a religious believer and a scientist—and his desire to reconcile the two fields.

Although the Galileo controversy is often portrayed in modern times as a conflict between religion and science, Galileo’s letter shows us that it was more of an intramural dispute within the church about the relationship between faith and reason. Although the dispute ended sadly for Galileo, his ideas—which hearkened back to the original Christian thought of St. Augustine and others—were eventually vindicated and adopted as the standard view of the Catholic Church regarding the relationship between religion and science. The “Letter to the Grand Duchess Christina” is part of the extensive literature on the relationship between faith and reason.

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