The geocentric and

theories.

246

Geocentric and Heliocentric Doctrines.

form, rotation on its axis, and a movement in space; he believed that it moves round the sun, and both together round the pole of the universe.

By geocentric theory is meant that doctrine which asserts heliocentric the earth to be the immovable centre of the universe; by heliocentric theory that which demonstrates the sun to be the centre of our planetary system, implying, as a necessary inference, that the earth is a very small and subordinate body revolving round the sun.

The geocenI have already, in sufficient detail, described how the Roman tric doctrine adopt- Church had been constrained by her position to uphold the ed by the Church. geocentric doctrine. She had come to regard it as absolutely essential to her system, the intellectual basis of which she held would be sapped if this doctrine should be undermined. Hence it was that such an alarm was shown at the assertion of the globular form of the earth, and hence the surpassing importance of the successful voyage of Magellan's ship. That indisputable demonstration of the globular figure was ever a solid support to the scientific party in the portentous approaching conflict.

Preparations for

the helio

centric doc

trine.

Preparations had been silently making for a scientific revolution in various directions. The five memoirs of Cardinal Alliacus On the Concordance of Astronomy with Theology,' show the turn that thought was taking. His 'Imago Mundi' was published in 1460, and is said to have been a favourite work with Columbus. In the very Cathedral of Florence, Toscanelli had constructed his celebrated gnomon, 1468; a sun-ray, auspicious omen! being admitted through a plate of brass in the lantern of the cupola. John Müller, better known as Regiomontanus, had published an abridgment of Ptolemy's 'Almagest,' 1520. Euclid had been printed with diagrams on copper as long before as 1482, and again in Venice twentythree years subsequently. The 'Optics' of Vitello had been published 1533. Fernel, physician to Henry II. of France, had even ventured so far, supported by Magellan's voyage, as to measure, 1527, the size of the earth, his method being to observe the height of the pole at Paris, then to proceed northward until its elevation was increased exactly one degree, and

to ascertain the distance between the stations by the number of revolutions of his carriage wheel. He concluded that it is 24,480 Italian miles round the globe. The last attempt of the kind had been that of the Khalif Almaimon, seven hundred years previously on the shore of the Red Sea, and with nearly the same result. The mathematical sciences were undergoing rapid advancement. Rhæticus had published his trigonometrical tables; Cardan, Tartaglia, Scipio Ferreo, and Stefel were greatly improving algebra.

the works

The first formal assertion of the heliocentric theory was Copernicus, made in a timid manner, strikingly illustrative of the expected of. opposition. It was by Copernicus, a Prussian, speaking of the revolutions of the heavenly bodies; the year was about 1536. In his preface, addressed to Pope Paul III., whether written by himself, or, as some have affirmed, for him by Andreas Osiander, he complains of the imperfections of the existing system, states that he has sought among ancient writers for a better way, and so had learned the heliocentric doctrine. "Then I too began to meditate on the motion of the earth, and, though it appeared an absurd opinion, yet, since I knew that in previous times others had been allowed the privilege of feigning what circles they chose in order to explain the phenomena, I conceived that I might take the liberty of trying whether, on the supposition of the earth's motion, it was possible to find better explanations than the ancient ones of the revolutions of the celestial orbs."

"Having, then, assumed the motions of the earth, which are hereafter explained, by laborious and long observation I at length found that, if the motions of the other planets be compared with the revolution of the earth, not only their phenomena follow from the suppositions, but also that the several orbs and the whole system are so connected in order and magnitude that no one point can be transposed without disturbing the rest, and introducing confusion into the whole universe."

tion of his

The apologetic air with which he thus introduces his doctrine Introducis again remarked in his statement that he had kept his book system. for thirty-six years, and only now published it at the entreaty

He fears being accused of heresy.

Early correction of

the Coper

nican the. ory.

of Cardinal Schomberg. The Cardinal had begged of him a manuscript copy. "Though I know that the thoughts of a philosopher do not depend on the judgment of the many, his study being to seek out truth in all things as far as is permitted by God to human reason, yet, when I considered how absurd my doctrine would appear, I long hesitated whether I should publish my book, or whether it were not better to follow the example of the Pythagoreans and others, who delivered their doctrine only by tradition and to friends." He concludes: "If there be vain babblers, who, knowing nothing of mathematics, yet assume the right of judging on account of some place of Scripture perversely wrested to their purpose, and who blame and attack my undertaking, I heed them not, and look upon their judgments as rash and contemptible."

Copernicus clearly recognized not only the relative position of the earth, but also her relative magnitude. He says the magnitude of the world is so great that the distance of the earth from the sun has no apparent magnitude when compared with the sphere of the fixed stars.

To the earth Copernicus attributed a triple motion-a daily rotation on her axis, an annual motion round the sun, a motion of declination of the axis. The latter seemed to be necessary to account for the constant direction of the pole; but as this was soon found to be a misconception, the theory was relieved of it. With this correction, the doctrine of Copernicus presents a clear and great advance, though in the state in which he offered it he was obliged to retain the mechanism of epicycles and eccentrics, because he considered the planetary motions to be circular. It was the notion that, since the circle is the most simple of all geometrical forms, it must therefore be the most natural, which led to this imperfection. His work was published in 1543. He died a few days after he had seen a copy.

Against the opposition it had to encounter, the heliocentric theory made its way slowly at first. Among those who did adopt it were some whose connection served rather to retard its progress, because of the ultraism of their views or the doubtfulness of their social position. Such was Bruno, who

Bruno of

the helio

theory.

contributed largely to its introduction into England, and who Giordano was the author of a work on the 'Plurality of Worlds,' and Nola. of the conception that every star is a sun, having opaque planets revolving round it,—a conception to which the Copernican system suggestively leads. Bruno was born seven years after the death of Copernicus. He became a Dominican, but, like so many other thoughtful men of the times, was led into heresy on the doctrine of transubstantiation. Not concealing his opinions, he was persecuted, fled, and led a vagabond life in foreign countries, testifying that wherever he went he found scepticism under the polish of hypocrisy, and that he fought not against the belief of men, but against their pretended belief. For teaching the rotation of the earth he had to flee to He teaches Switzerland, and thence to England, where, at Oxford, he gave centric lectures on cosmology. Driven from England, France, and Germany in succession, he ventured in his extremity to return to Italy, and was arrested in Venice, where he was kept in prison in the Piombi for six years, without books, or paper, or friends. Meantime the Inquisition demanded him as having written heretical works. He was therefore surrendered to Rome, and, after a further imprisonment of two years, tried, excommunicated, and delivered over to the secular authorities, to be punished "as mercifully as possible, and without the shedding of his blood," the abominable formula for burning a man alive. He had collected all the observations that had been made respecting the new star in Cassiopeia, 1572; he had taught that space is infinite, and that it is filled with selfluminous and opaque worlds, many of them inhabited,—this being his capital offence. He believed that the world is animated by an intelligent soul, the cause of forms but not of matter; that it lives in all things, even such as seem not to live; that everything is ready to become organized; that matter is the mother of forms and then their grave; that matter and the soul of the world constitute God. His ideas were therefore pantheistic, "Est Deus in nobis." In his 'Cena de le Cenere' he insists that the Scripture was not intended to teach science, but morals only. The severity with which he was treated was provoked by his asseverations that he was

And is

burnt alive

struggling with an orthodoxy that had neither morality nor belief. This was the aim of his work entitled 'The Triumphant Beast.' He was burnt at Rome, Febuary 16, 1600. as a heretic. With both a present and prophetic truth, he nobly responded, when the atrocious sentence was passed upon him, "Perhaps it is with greater fear that ye pass this sentence upon me than I receive it." His tormentors jocosely observed, as the flames shut him out for ever from view, that he had gone to the imaginary worlds he had so wickedly feigned.

Lord Bacon.

doctrine.

This vigorous but spasmodic determination of the Church to defend herself was not without effect. It enabled her to hold fast the timid, the time-servers, the superficial. Among such may be mentioned Lord Bacon, who never received the Copernican system. With the audacity of ignorance, he presumed to criticize what he did not understand, and, with a Rejects the superb conceit, disparaged the great Copernicus. He says, Copernican "In the system of Copernicus there are many and grave difficulties; for the threefold motion with which he encumbers the earth is a serious inconvenience, and the separation of the sun from the planets, with which he has so many affections in common, is likewise a harsh step; and the introduction of so many immovable bodies in nature, as when he makes the sun and stars immovable, the bodies which are peculiarly lucid and radiant, and his making the moon adhere to the earth in a sort of epicycle, and some other things which he assumes, are proceedings which mark a man who thinks nothing of introducing fictions of any kind into nature, provided his calculations turn out well." The more closely we examine the writings of Lord Bacon, the more unworthy does he seem to have been of the great reputation which has been awarded to him. The popular delusion to which he owes so much originated at a time when the history of science was unknown. They who first brought him into notice knew nothing of the old school of Alexandria. This boasted founder of a new philosophy could not comprehend, and would not accept, the greatest of all scientific doctrines when it was plainly set before his eyes.

It has been represented that the invention of the true method of physical science was an amusement of Bacon's