Riccioli nevertheless viewed the Copernican system with much sympathy. After a full statement of it, he comments: "We have not yet exhausted the full profundities of the Copernican hypothesis, for the deeper one digs into it, the more ingenious and valuable subtilties may one unearth." Then he adds that "the greatness of Copernicus has never been sufficiently appreciated nor will it be,—that man who accomplished what no astronomer before him had scarcely been able even to suggest without an insane machinery of spheres, for by a triple motion of the earth he abolished epicycles and eccentrics. What before so many Atlases could not support, this one Hercules has dared to carry. Would that he had kept himself within the limits of his hypothesis!"[341]
His conclusions seem to show that only his position as a Jesuit restrained him from being a Copernican himself.[342] "I. If the celestial phenomena alone are considered, they are equally well explained by the two hypotheses [Ptolemaic and Copernican]. II. The physical evidence as explained in the two systems with exception of percussion and the speed of bodies driven north or south, and east or west, is all for immobility. III. One might waver indifferently between the two hypotheses aside from the witness of the Scriptures, which settles the question. IV. There are in addition plenty of other motives besides Scriptural ones for rejecting this system." (!) But with the Scriptural evidence he adduces the decree of the Index under Paul V against the doctrine, and the sentence of Galileo, so that "the sole possible conclusion is that the earth stands by nature immobile in the center of the universe, and the sun moves around it with both a diurnal and an annual motion."[343]
Even this great book was as insufficient to stop the criticism of the action of the Congregations, as it was to stop the spread of the doctrine. So once again the father took up the cudgels in defense of the Church. The full title of his Apologia runs: "An Apologia in behalf of an argument from physical mathematics against the Copernican system, directed against that system by a new argument from the reflex motion of falling weights." (Venice, 1669). He states in this that his Almagestum Novum had received the approbation of professors of mathematics at Bologna, of one at Pisa, and of another at Padua, and he quotes the conclusion from Nicetas Orthodoxus ("a diatribe by Julius Turrinus, doctor of mathematics, philosophy, medicine, law, and Greek letters"): "That the sun is revolved by diurnal and by annual motion, and that the earth is at rest I firmly hold, infallibly believe, and openly confess, not because of mathematical reasons, but solely at the command of faith, by the authority of the Scriptures, and the nod of approval (nutu) of the Roman See, whose rules laid down at the dictation of the spirit of truth, may I, as befits everyone, uphold as law."[344]
Riccioli further on proceeds to answer his objecters, declaring that "the Church did not decide ex cathedra that the Scripture concerning movement should be interpreted literally; that the censure was laid by qualified theologians and approved by eminent cardinals, and was not merely provisional, nor for the time being absolute, since the contrary could never be demonstrated; and that while it was the primary intent of the Inquisitors to condemn the opinion as heretical and directly contrary to the Scriptures ... they added that it was absurd and false also in philosophy, in order, not to avert any objections which could be on the side of philosophy or astronomy, but only lest any one should say that Scripture is opposed to philosophy."[345] These answers are indicative of the type of criticism with which the Church had to cope even at that time.[346]
CHAPTER IV.
The Gradual Acceptance of the Copernican System.
JUST as Tycho Brahe's system proved to be for some a good half-way station between the improbable Ptolemaic and the heretical Copernican system;[347] so the Cartesian philosophy helped others to reconcile their scientific knowledge with their reverence for the Scriptures, until Newton's work had more fully demonstrated the scientific truth.
Its originator, Réné Descartes[348] (1596-1650) was in Holland when word of Galileo's condemnation reached him in 1633, as he was seeking in the bookshops of Amsterdam and Leyden for a copy of the Dialogo.[349] He at once became alarmed lest he too be accused of trying to establish the movement of the earth, a doctrine which he had understood was then publicly taught even in Rome, and which he had made the basis of his own philosophy. If this doctrine were condemned as false, then his philosophy must be also; and, true to his training by the Jesuits, rather than go against the Church he would not publish his books. He set aside his Cosmos, and delayed the publication of the Méthode for some years in consequence, even starting to translate it into Latin as a safeguard.[350] His conception of the universe, the Copernican one modified to meet the requirements of a literally interpreted Bible, was not printed until 1644, when it appeared in his Principes.[351]
According to this statement which he made only as a possible explanation of the phenomena and not as an absolute truth, while there was little to choose between the Tychonic and the Copernican conceptions, he inclined slightly toward the former. He conceived of the earth and the other planets as each borne along in its enveloping heaven like a ship by the tide, or like a man asleep on a ship that was sailing from Calais to Dover. The earth itself does not move, but it is transported so that its position is changed in relation to the other planets but not visibly so in relation to the fixed stars because of the vast intervening spaces. The laws of the universe affect even the most minute particle, and all alike are swept along in a series of vortices, or whirlpools, of greater or less size. Thus the whole planetary system sweeps around the sun in one great vortex, as the satellites sweep around their respective planets in lesser ones. In this way Descartes worked out a mechanical explanation of the universe of considerable importance because it was a rational one which anyone could understand. Its defects were many, to be sure, as for example, that it did not allow for the elliptical orbits of the planets;[352] and one critic has claimed that this theory of a motionless earth borne along by an enveloping heaven was comparable to a worm in a Dutch cheese sent from Amsterdam to Batavia,—the worm has travelled about 6000 leagues but without changing its place![353] But this theory fulfilled Descartes's aim: to show that the universe was governed by mechanical laws of which we can be absolutely certain and that Galileo's discoveries simply indicated this.[354]