Galileo Galilei, one of the great leaders of the 17th century’s Scientific Revolution, is generally credited as being the first person to use the telescope for astronomical purposes, the discoverer of four of Jupiter’s moons (along with many other celestial phenomena), and a strong advocate of the Copernican (heliocentric) model of the solar system.  It is the last item of the preceding list, his Copernican views, which got him into a “bit” of trouble with the Catholic Church in 1633.  Galileo had been, both subtly and not so subtly, an adversary of the Church for years previous to his actual inquisition proceedings.  Believing that religion and science should be separate and independent entities, he did his best to mention religion as infrequently as possible in his scientific writings.  As a learned man, however, he realized that religion was one of the dominant powers of the era, and he sometimes tried to use this fact to his advantage.  He particularly seemed to take relish in using religion to contradict itself, as can be seen by analyzing one of his letters to the Grand Duchess Christina.  While he formally retracts his “heretical” propositions to save his life, it is fairly apparent that he never truly believes that religion has a place in the scientific world.

Galileo’s intellectual works are his safe haven from the pressures and compromises of the outside world.  Here, he knows that scientists are his only real audience, and so he doesn’t need to insert religion into his writing to appease anyone.  A perfect case study of his scientific prose is “The Starry Messenger.”  Within the Astronomical Message, he mentions God a grand total of zero times—for him, there is no need to do so (“Starry” 21-58).  As is evidenced in his letter to the Grand Duchess, which will be analyzed shortly, he would prefer his scientific work to stand on its own merits.  He sees no reason to compare his work to what is written in the Bible, and so he simply does not.  This way of thinking differs greatly from Isaac Newton’s.  Since Newton believed strongly in God (he believed, in fact, that by unraveling the mysteries of science he was only discovering the laws by which God had created the universe), religious ideas and references pervaded even the most central of his theses.  Some of his “proofs,” in fact, such as his notion that the planets existed where they existed because those are the only locations where intersecting perfect spheres would place them, spawned from Newton’s belief that the universe was “perfect” because God created the universe, and God was incapable of creating flawed works (Newton, 543-547).  Galileo would object strongly to such reasoning, since he felt that science shouldn’t draw from religion in any way to form hypotheses.

So far, no real proof has been given as to how Galileo truly felt about the relationship between science and religion.  The preceding example would certainly fit the hypothesis presented, but direct evidence can be found by looking at a 1615 letter that Galileo penned to the Grand Duchess Christina (Christina, 175-216).  To fully comprehend this letter, we need to analyze it on three separate levels.

On the first level, we assume that Galileo truly believes everything he sets forth in the letter.  He is being sincere, straightforward, and honest without even a hint of arrogance or sarcasm.  He truly believes that evidence from within religion itself, such as numerous quotes from St. Augustine and other sources, show valid reasons why the Bible shouldn’t be taken seriously as a method of explaining the physical world.  Augustine appears to be Galileo’s favorite religious figure, and for good reason: his views closely match those of Galileo’s.  As Augustine states, “…but to undertake an examination of the physical world based solely on the Bible 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 conducting to their salvation and to the benefit of the holy Church” (Christina, 185).  Augustine was referring to a specific debate concerning whether the heavens were fixed or moved, and the reply, put more simply: there is no real way to resolve this conflict through analysis of the Bible, and attempting to do so is a waste of time that could more profitibly be spent improving the Church in other ways.  Galileo grows even bolder as the letter progresses, actually daring to show a point at which the Bible appears to contradict itself.  He speaks of a Biblical passage which recounts a time when Joshua commanded the sun to stand still.  Going on to explain the concept of the primum mobile, Galileo reasons that making the sun appear to stand still with relation to the earth would actually entail, “accelerating the customary speed of the sun about three hundred sixty times” (Christina 211).  These reasonings, however, would seem to be contrary to Galileo’s entire point: why is he using religion as a source of physical argument if he detests religion’s use as such?  This contradiction leads us into the second level of analysis.

On the second level, we take into consideration his actual conclusions.  The main thrust of the letter, as just stated, was to debunk religion as an accurate means of explaining the physical reality.  This raises the question: how can he use as argument something he has just disqualified from being valid evidence?  If the Bible cannot explain physical reality, how can Galileo feasibly use it to debunk the notion that it can?  More interestingly, why would he choose to use it as an argument?  As he himself states (in the same very passage!), “I think that in discussions of physical problems we ought to begin not from the authority of scriptural passages, but from sense-experiences and necessary demonstrations…” (Christina 182).  If this level of interpretation is taken to be totally correct, than Galileo has completely nullified his own argument simply by presenting it in the first place.  Thus, this explanation is a good intermediate analysis, but it doesn’t serve to show Galileo’s true motives for writing the letter.  We require a third level of analysis.

On the third level, we bring the reasoning of what Galileo would refer to as the “common man” into the mix.  Galileo knows that religion was an integral part of nearly every single person’s life in the time during which he lived, and so he reasons that religious arguments hold more weight than scientific proofs among the so-called “common man.”  He also notes that some passages within the Bible itself may have been simplified for the benefit of common men, to make it easier for them to understand its contents.  Galileo states as much to Christina within the letter, as he says, “These propositions uttered by the Holy Ghost were set down in that manner by the sacred scribes in order to accommodate them to the capacities of the common people, who are rue and unlearned.” (Christina 181)  It’s fairly ironic that Galileo conspiratorially shares his feelings about the stupidity of the common man to Christina, and then he turns around and uses the same sorts of techniques one would use on a common man on the Grand Duchess herself.  As a learned person, he would never use religion as an argument to a fellow learned person (as is seen by the lack of biblical references in his scientific works), but he has no problem doing this to Christina—apparently a “common man.”

So, is there any truth at all underneath the three layers of lies Galileo weaves in his letter to the Grand Duchess?  It is apparent that he believes that the Biblical writers wrote “down” to the common people—after all, he uses the same trick on Christina.  It is also apparent that he believes religion has no place in the scientific world, even if the evidence he presents to this end is flawed.

Galileo’s letter to Cosimo de Medici has several similarities to the letter to the Grand Duchess.  He again utilizes religion to his advantage, here actually using it to praise Cosimo.  This follows Galileo’s “common man” theme of talking down to people he needs to impress by using religion.  He proclaims that God intended the recently discovered moons to be named after Cosimo because of his similarities to Jupiter.  While Galileo himself surely sees this as preposterous, he knows that de Medici might just believe it.  He repeats the same sort of trick later on, when he exclaims, “…it pleased Almighty God that I should instruct Your Highness in mathematics….” (“Starry” 25)  He is claiming that Galileo was chosen to tutor Cosimo because of divine intervention!  Again, because of the prevalence of strong religious ideas at that time, he fully expects Cosimo to believe this.

The conflict between Galileo and the Catholic Church came to a head in 1633, when that body set formal inquisition proceedings in motion against him.  These proceedings don’t offer much insight into Galileo’s true feelings about the relationship between religion and science, primarily because he was given rather unpleasant options to choose from: he could rescind his support of Copernican views, or be tortured and presumably killed.  He chose to rescind his statements—under much duress, obviously—sounding like a perfect choirboy as he does so.  The one bit of information we do gain about Galileo’s attitude can be extrapolated from his defense of himself prior to his forced confession.  In 1615, Galileo was instructed by officials of the Church that the Copernican model “was contrary to Holy Scripture and that one could not hold or defend it, except as a supposition.” (Inquisition 284)  Verbally mentioned, but not written in the actual decree, was that Galileo was not “to teach in any way whatsoever” the works of Copernicus.  Galileo’s main defense for publishing a book that contained descriptions of the heliocentric model was that the latter phrase had been left off the official decree, and so Galileo had simply forgotten about it during the ensuing 16 years.  This entire argument is a giant nit-pick.  It is improbable that Galileo would forget any portion of a conversation with a high-ranking church official, especially when they happen to relate directly to his entire life’s work.  It is much more likely that he saw the omission in the decree right away, and simply chose to use it in his seemingly never-ending quest to spite the Catholic Church.  It’s also extremely unlikely that, as he states, upon rereading his work to see if it appeared to be heretical, “it appeared to me in several places to be written in such a way that a reader, not aware of my intention, would have had reason to form the opinion that the arguments for the false side, which I intended to confute, were so stated as to be capable of convincing because of their strength, rather than being easy to answer.” (Inquisition, 284-285)  No professional author would fail to realize for so long that a section of his paper—in this case the main thesis itself—could be misconstrued, especially not one of Galileo’s caliber.  Again, it is much more likely (and much more agreeable to the notion of Occam’s Razor) that he wrote the paper as such because he intended the passage to present strong arguments for the Copernican model without directly appearing to do so.

Can we truly enter Galileo’s mind and know for certain what he really thought of religion?  Can we know whether he for certain felt that religion had no place in the scientific world?  We cannot, and there would be no way we possibly could besides going back in time and asking him.  But, by analyzing hidden clues and ideas in his writings, it is possible to “play the odds” with regard to Galileo’s true beliefs.  Judging from the evidence he has left behind, it seems extremely likely that Galileo wished that religion had never come about.  Being that religion does exist, he wanted to have as little to do with it as possible—especially when it came to his discoveries.
 
 
 
 
 

Works Cited
 

Documents from the Inquisition proceedings against Galileo (from Maurice A. Finocchiaro, The Galileo Affair: A Documentary History, University of California Press, 1989). pp. 281-293.
 

Galilei, Galileo.  “The Starry Messenger,” Discoveries and Opinions of Galileo.  New York: Anchor Books, 1957; pp. 21-58.
 

Galilei, Galileo.  “Letter to the Grand Duchess Christina,” Discoveries and Opinions of Galileo.  New York: Anchor Books, 1957. pp. 175-216.
 

Sir Isaac Newton’s Mathematical Principles of Natural Philosophy and His System of the World (2nd edition, 1713; English translation, 1729), University of California Press paperback edition, 1966. pp. 543-547.