Copernican theory. 10. It can excite no wonder that the system of Copernicus, simple and beautiful as it is, met with little encouragement for a long time after its promulgation, when we reflect upon the natural obstacles to its reception. Mankind can in general take these theories of the celestial movements only upon trust from philosophers; and in this instance it required a very general concurrence of competent judges to overcome the repugnance of what called itself common sense, and was in fact a prejudice as natural, as universal, and as irresistible as could influence human belief. With this was united another, derived from the language of Scripture; and though it might have been sufficient to answer, that phrases implying the rest of the earth and motion of the sun are merely popular, and such as those who are best convinced of the opposite doctrine must employ in ordinary language, this was neither satisfactory to the vulgar, nor recognised by the church. Nor were the astronomers in general much more favourable to the new theory than either the clergy or the multitude. They had taken pains to familiarise their understandings with the Ptolemaic hypothesis; and it may be often observed that those who have once mastered a complex theory are better pleased with it than with one of more simplicity. The whole weight of Aristotle’s name, which, in the sixteenth century, not only biassed the judgment, but engaged the passions, connected as it was with general orthodoxy and preservation of established systems, was thrown into the scale against Copernicus. It was asked what demonstration could be given of his hypothesis; whether the movements of the heavenly bodies could not be reconciled to the Ptolemaic; whether the greater quantity of motion, and the complicated arrangement which the latter required, could be deemed sufficient objections to a scheme proceeding from the Author of nature, to whose power and wisdom our notions of simplicity and facility are inapplicable; whether the moral dignity of man, and his peculiar relations to the Deity, unfolded in Scripture, did not give the world he inhabits a better claim to the place of honour in the universe, than could be pretended, on the score of mere magnitude, for the sun. It must be confessed, that the strongest presumptions in favour of the system of Copernicus were not discovered by himself.
11. It is easy, says Montucla, to reckon the number of adherents to the Copernican theory during the sixteenth century. After Rhæticus, they may be nearly reduced to Reinold, author of the Prussian tables; Rothman, whom Tycho drew over afterwards to his own system; Christian Wursticius (Ursticius), who made some proselytes in Italy; finally, Mæstlin, the illustrious master of Kepler. He might have added Wright and Gilbert, for the credit of England. Among the Italian proselytes made by Wursticius, we may perhaps name Jordano Bruno, who strenuously asserts the Copernican hypothesis; and two much greater authorities in physical science, Benedetti and Galileo himself. It is evident that the preponderance of valuable suffrages was already on the side of truth.[1361]
[1361] Montucla, p. 638.
Tycho Brahe. 12. The predominant disinclination to contravene the apparent testimonies of sense and Scripture had, perhaps, more effect than the desire of originality in suggesting the middle course taken by Tycho Brahe. He was a Dane of noble birth, and early drawn by the impulse of natural genius to the study of astronomy. Frederic III., his sovereign, after Tycho had already obtained some reputation, erected for him the observatory of Uraniburg in a small isle of the Baltic. In this solitude he passed above twenty years, accumulating the most extensive and accurate observations which were known in Europe before the discovery of the telescope and the improvement of astronomical instruments. These, however, were not published till 1606, though Kepler had previously used them in his Tabulæ Rodolphinæ. Tycho himself did far more in this essential department of the astronomer than any of his predecessors; his resources were much beyond those of Copernicus, and the latter years of this century may be said to make an epoch in physical astronomy. Frederic, Landgrave of Hesse, was more than a patron of the science. The observations of that prince have been deemed worthy of praise long after his rank had ceased to avail them. The emperor Rodolph, when Tycho had been driven by envy from Denmark, gave him an asylum and the means of carrying on his observations at Prague, where he died in 1601. He was the first in modern times who made a catalogue of stars, registering their positions as well as his instruments permitted him. This catalogue, published in his Progymnasmata in 1602, contained 777, to which, from Tycho’s own manuscripts, Kepler added 223 stars.[1362]
[1362] Montucla, p. 653-659.
His system. 13. In the new mundane system of Tycho Brahe, which, though first regularly promulgated to the world in his Progymnasmata, had been communicated in his epistles to the Landgrave of Hesse, he supposes the five planets to move round the sun, but carries the sun itself with these five satellites, as well as the moon, round the earth. Though this, at least at the time, might explain the known phenomena as well as the two other theories, its want of simplicity always prevented its reception. Except Longomontanus, the countryman and disciple of Tycho, scarce any conspicuous astronomer adopted an hypothesis which, if it had been devised some time sooner, would perhaps have met with better success. But in the seventeenth century, the wise all fell into the Copernican theory, and the many were content without any theory at all.
14. A great discovery in physical astronomy may be assigned to Tycho. Aristotle had pronounced comets to be meteors generated below the orbit of the moon. But a remarkable comet in 1577 having led Tycho to observe its path accurately, he came to the conclusion that these bodies are far beyond the lunar orbit, and that they pass through what had always been taken for a solid firmament, environing the starry orbs, and which plays no small part in the system of Ptolemy. He was even near the discovery of their elliptic revolution; the idea of a curve round the sun having struck him, though he could not follow it by observation.[1363]
[1363] Montucla, p. 662.
Gregorian calendar. 15. The acknowledged necessity of reforming the Julian calendar gave in this age a great importance to astronomy. It is unnecessary to go into the details of this change, effected by the authority of Gregory XIII., and the skill of Lilius and Clavius, the mathematicians employed under him. The new calendar was immediately received in all countries acknowledging the pope’s supremacy; not so much on that account, though a discrepancy in the ecclesiastical reckoning would have been very inconvenient, as of its real superiority over the Julian. The protestant countries came much more slowly into the alteration; truth being no longer truth, when promulgated by the pope. It is now admitted that the Gregorian calendar is very nearly perfect, at least as to the computation of the solar year, though it is not quite accurate for the purpose of finding Easter. In that age, it had to encounter the opposition of Mæstlin, an astronomer of deserved reputation, and of Scaliger, whose knowledge of chronology ought to have made him conversant with the subject, but who, by a method of squaring the circle, which he announces with great confidence as a demonstration, showed the world that his genius did not guide him to the exact sciences.[1364]
[1364] Montucla, p. 674-686.