Galileo's treatise on "The Authority of Scripture in Philosophical Controversies" was written at a time when the Copernican theory of the constitution of the universe was engaging the attention of the world. A Benedictine monk, Benedetto Castelli, called upon to defend the theory at the grand-ducal table of Tuscany, asked Galileo's assistance in reconciling it with orthodoxy. His answer was an exposition of a formal theory as to the relations of physical science to Holy Writ. This answer was further amplified in the "Authority of the Scripture," addressed in 1614 to Christina of Lorraine, Dowager Grand-Duchess of Tuscany, an able and acute defence of his position. A year later another monk laid Galileo's letter to Castelli before the Inquisition, whereupon the philosopher was summoned by Pope Paul V. to the palace of Cardinal Bellarmine, and there warned against henceforth holding, teaching, or defending the condemned doctrine. Nevertheless, in a few years Galileo had to suffer trial and condemnation by the Inquisition for publishing his "Dialogues on the System of the World," which gave the Ptolemaic theory its death-blow.
I.--The Defenders of Fallacy
Some years ago I discovered many astronomical facts till then unknown. Their novelty and their antagonism to some physical propositions commonly received by the schools did stir up against me many who professed the vulgar philosophy, as if, forsooth, I had with my own hand placed these things in the heavens to obscure and disturb nature and science. These opponents, more affectionate to their own opinion than to truth, tried to deny and disprove my discoveries, which they might have discerned with their own eyes; and they published vain discourses, interwoven with irrelevant passages, not rightly understood, of the sacred Scriptures. From this [pg 130] folly they might have been saved had they rememberedthe advice of St. Augustine, who, dealing with celestial bodies, writes: "We ought to believe nothing unadvisedly in a doubtful point, lest in favour of our error we conceive a prejudice against that which truth hereafter may discover to be nowise contrary to the sacred books."
Time has proved every one of my statements, and proving them has also proved that my opponents were of two kinds. Those who had doubted simply because the discoveries were new and strange have been gradually converted, while those whose incredulity was based on personal ill-will to me have shut their eyes to the facts and have endeavoured to asperse my moral character and to ruin me.
Knowing that I have confuted the Ptolemaic and Aristotelian arguments, and distrusting their defence in the field of philosophy, they have tried to shield their fallacies under the mantle of a feigned religion and of scriptural authority, and have endeavoured to spread the opinion that my propositions are contrary to the Scriptures, and therefore heretical. To this end they have found accomplices in the pulpits, and have scattered rumours that my theory of the world-system would ere long be condemned by supreme authority.
Further, they have endeavoured to make the theory peculiar to myself, ignoring the fact that the author, or rather restorer, of the doctrine was Nicholas Copernicus, a Catholic, and a much-esteemed priest, who was summoned to Rome to correct the ecclesiastic calendar, and in the course of his inquiries reached this view of the universe.
The calendar has since been regulated by his doctrine, and on his principles the motions of the planets have been calculated. Having reduced his doctrine to six books, he published them under the title of "De Revolutionibus Coelestibus," at the instance of the Cardinal [pg 131] of Capua, and of the Bishop of Culma; and, sincehe undertook the task at the order of Pope Leo X., he dedicated the work to his successor Paul III., and it was received by the Holy Church and studied by all the world.
In the end of his dedicatory epistle Copernicus writes: "If there should chance to be any mateologists who, ignorant in mathematics yet pretending to skill in that science, should dare, upon the authority of some passage of Scripture wrested to their purpose, to condemn and censure my hypothesis, I value them not, and scorn their inconsiderate judgment. For it is not unknown that Lactantius (a famous author though poor mathematician) writes very childishly concerning the form of the earth when he scoffs at those who affirm the earth to be in form of a globe. So that it ought not to seem strange to the intelligent if any such should likewise now deride us. The mathematics are written for mathematicians, to whom (if I deceive not myself) these labours of mine shall seem to add something, as also to the commonweal of the Church whose government is now in the hands of Your Holiness."
It is such as Lactantius who would now condemn Copernicus unread, and produce authorities of the Scripture, of divines, and of councils in support of their condemnation. I hold these authorities in reverence, but I hold that in this instance they are used for personal ends in a manner very different from the most sacred intention of the Holy Church. I am ready to renounce any religious errors into which I may run in this discourse, and if my book be not beneficial to the Holy Church may it be torn and burnt; but I hold that I have a right to defend myself against the attacks of ignorant opponents.
The doctrine of the movement of the earth and the fixity of the sun is condemned on the ground that the Scriptures speak in many places of the sun moving and [pg 132] the earth standing still. The Scriptures not being capableof lying or erring, it followeth that the position of those is erroneous and heretical who maintain that the sun is fixed and the earth in motion.
It is piously spoken that the Scriptures cannot lie. But none will deny that they are frequently abstruse and their true meaning difficult to discover, and more than the bare words signify. One taking the sense too literally might pervert the truth and conceive blasphemies, and give God feet, and hands, and eyes, and human affections, such as anger, repentance, forgetfulness, ignorance, whereas these expressions are employed merely to accommodate the truth to the mental capacity of the unlearned.
This being granted, I think that in the discussion of natural problems we ought to begin not with the Scriptures, but with experiments and demonstrations. Nor does God less admirably discover Himself to us in nature than in Scripture, and having found the truth in nature we may use it as an aid to the true exposition of the Scriptures. The Scriptures were intended to teach men those things which cannot be learned otherwise than by the mouth of the Holy Spirit; but we are meant to use our senses and reason in discovering for ourselves things within their scope and capacity, and hence certain sciences are neglected in the Holy Writ.
Astronomy, for instance, is hardly mentioned, and only the sun, and the moon, and Lucifer are named. Surely, if the holy writers had intended us to derive our astronomical knowledge from the Sacred Books, they would not have left us so uninformed. That they intentionally forbore to speak of the movements and constitution of the stars is the opinion of the most holy and most learned fathers. And if the Holy Spirit has omitted to teach us those matters as not pertinent to our salvation, how can it be said that one view is de Fide and the other heretical? I might here insert the opinion [pg 133] of an ecclesiastic raised to the degree of Eminentissimo:That the intention of the Holy Ghost is to teach us how we shall go to Heaven, and not how the heavens go.
II.--Scriptural and Experimental Truth
Since the Holy Writ is true, and all truth agrees with truth, the truth of Holy Writ cannot be contrary to the truth obtained by reason and experiment. This being true, it is the business of the judicious expositor to find the true meaning of scriptural passages which must accord with the conclusions of observation and experiment, and care must be taken that the work of exposition do not fall into foolish and ignorant hands. It must be remembered that there are very few men capable of understanding both the sacred Scriptures and science, and that there are many with a superficial knowledge of the Scriptures and with no knowledge of science who would fain arrogate to themselves the power of decreeing upon all questions of nature. As St. Jerome writes: "The talking old woman, the dotard, the garrulous sophist, all venture upon, lacerate, teach, before they have learnt. Others, induced by pride, dive into hard words, and philosophate among women touching the Holy Scriptures. Others (oh, shameful!) learn of women what they teach to men."
I will not rank among these same secular writers any theologists whom I repute to be men of profound learning and sober manners, and therefore hold in great esteem and veneration; yet it vexes me when they would constrain science by the authority of the Scriptures, and yet do not consider themselves bound to answer reason and experiment. It is true that theology is the queen of all the sciences, but queen only in the sense that she deals with high matters revealed in noble ways, and if she condescends not to study the more humble matters of the inferior sciences she ought not to arrogate to herself [pg 134] the right to judge them; for this would be as if anautocratic prince, being neither physician nor architect, should undertake to administer medicines and erect buildings to the danger of the lives of his subjects.
Again, to command the professors of astronomy to confute their own observations is to enjoin an impossibility, for it is to command them not to see what they do see, and not to understand what they do understand, and to find what they do not discover. I would entreat the wise and prudent fathers to consider the difference between matters of opinion and matters of demonstration, for demonstrated conclusions touching the things of nature and of the heavens cannot be changed with the same facility as opinions touching what is lawful in a contract, bargain, or bill of exchange. Your highness knows what happened to the late professor of mathematics in the University of Pisa--how, believing that the Copernican doctrine was false, he started to confute it, but in his study became convinced of its truth.
In order to suppress the Copernican doctrine, it would be necessary not only to prohibit the book of Copernicus and the writings of authors who agree with him, but to interdict the whole science of astronomy, and even to forbid men to look at the sky lest they might see Mars and Venus at very varying distances from the earth, and discover Venus at one time crescent, at another time round, or make other observations irreconcilable with the Ptolemaic system.
It is surely harmful to souls to make it a heresy to believe what is proved. The prohibition of astronomy would be an open contempt of a hundred texts of the Holy Scriptures, which teach us that the glory and the greatness of Almighty God are admirably discerned in all His works, and divinely read in the open book of the heavens.
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III.--Fact and Faith
It may be said that the doctrine of the movement of the sun and the fixity of the earth must de Fide be held for true since the Scriptures affirm it, and all the fathers unanimously accept the scriptural words in their naked and literal sense. But it was necessary to assign motion to the sun and rest to the earth lest the shallow minds of the vulgar should be confounded, amused, and rendered obstinate and contumacious with regard to doctrines of faith. St. Jerome writes: "It is the custom for the pen-men of Scripture to deliver their judgments in many things according to the common received opinion that their times had of them." Even Copernicus himself, knowing the power of custom, and unwilling to create confusion in our comprehension, continues to talk of the rising and setting of the sun and stars and of variations in the obliquity of the zodiac. Whence it is to be noted how necessary it is to accommodate our discourse to our accustomed manner of understanding.
In the next place, the common consent of the fathers to a natural proposition should authorise it only if it have been discussed and debated with all possible diligence, and this question was in those times totally buried.
Besides, it is not enough to say that the fathers accept the Ptolemaic doctrine; it is necessary to prove that they condemned the Copernican. Was the Copernican doctrine ever formally condemned as contrary to the Scriptures? And Didacus, discoursing on the Copernican hypothesis, concludes that the motion of the earth is not contrary to the Scriptures.
Let my opponents, therefore, apply themselves to examine the arguments of Copernicus and others; and let them not hope to find such rash and impetuous decisions in the wary and holy fathers, or in the absolute wisdom [pg 136] of him that cannot err, as those into which they havesuffered themselves to be hurried by prejudice or personal feeling. His holiness has certainly an absolute power of admitting or condemning propositions not directly de Fide, but it is not in the power of any creature to make them true or false otherwise than of their own nature and de facto they are.
In my judgment it would be well first to examine the truth of the fact (over which none hath power) before invoking supreme authority; for if it be not possible that a conclusion should be declared heretical while we are not certain but that it may be true, their pains are vain who pretend to condemn the doctrine of the mobility of the earth and the fixity of the sun, unless they have first demonstrated the doctrine to be impossible and false.
Let us now consider how we may interpret the command of Joshua that the sun should stand still.
According to the Ptolemaic system, the sun moves from east to west through the ecliptic, and therefore the standing still of the sun would shorten and not lengthen the day. Indeed, in order to lengthen the day on this system it would be necessary not to hold the sun, but to accelerate its pace about three hundred and sixty times. Possibly Joshua used the words to suit the comprehension of the ignorant people; possibly--as St. Augustine says--he commanded the whole system of the celestial spheres to stand still, and his command to the moon rather confirms this conjecture.
On the Copernican system interpretation is simplified; for if we consider the mobility of the sun and how it is in a certain sense the soul and heart of the universe, it is not illogical to say that it gives not only light, but also motion to the bodies round it. In this manner, by the standing still of the sun at Joshua's command, the day might be lengthened without disturbing the order of the universe or the mutual positions of the stars. This interpretation also explains the statement that the [pg 137] sun stood still in medio coeli. Had the sun been in themiddle of the heavens in the sense of rising and setting, it had hardly been necessary to check its course; but in medio coeli probably signifies in the middle or centre of the universe where it resides.
I have no doubt that other passages of the Scriptures could be likewise interpreted in accordance with the Copernican system by divines with knowledge of astronomy. They might say that the word "firmament" very well agrees, ad literam, with the starry sphere. Ad literam, if they admit the rotation of the earth, they might understand its poles, when it is said Nec dum terram fecerat, et flumina, et cardines orbis terrae. [Nor yet had He created the earth, or the rivers, or the hinges for the globe of the earth.] Surely cardines, or "hinges," are ascribed to the earth in vain if it be not to turn upon them.
