These and similar remarks of the scientific editor would tend to prove that the Congregation of the Holy Office had very good and substantial grounds for condemning the heliocentric theory, and that Galileo was a visionary; for the theory which he impugned was “confirmed by mathematics,” and “verified by confirming the power of astronomical prevision.” We are quite sure, however, that this is not what Mr. Youmans intended to prove; and yet it does not appear why he should fill a column of his magazine with such a panegyric of a defunct theory. We concede—and the fact has never been disputed—that astronomy owes an immense debt to the ante-Copernican investigators for their careful observations and laborious calculations; but we do not see how this has anything to do with Dr. Taylor’s criticism. Had the reverend doctor denied that there was any real knowledge of astronomy before Copernicus, his critic might have been justified in trying to enlighten him about the merits of the Ptolemaic astronomers; but Dr. Taylor had not committed himself on this point, and therefore had no apparent need of being enlightened on the subject. The information, consequently, which Mr. Youmans volunteers to offer him is superfluous, not to say impertinent, and, inasmuch as it professes to be an argument, is a complete failure; for it aims at proving what no one has ever denied.
But the scientific editor in giving his needless information commits another blunder, which we could hardly expect from a man of science, by affirming that the Ptolemaic theory “was elucidated and confirmed by mathematics.” Mathematics confirmed nothing but the order and quality of the phenomena, and the law of their succession. Before Kepler and Newton no mathematics could decide whether the sun revolved around the earth or the earth around the sun. Astronomical phenomena were known, but this knowledge was a knowledge of facts, not of their explanation. The Ptolemaic hypothesis was not inconsistent with the facts then observed, but it was _assumed_, not _verified_. If such a theory had been verified, its truth would be still recognized, and the Copernican theory would have had no chance of admission. But evidently it is not the theory that has been verified, but only the apparent movements of celestial bodies. Thus “the elaborate tables” by which the future positions of the planets could be foretold prove indeed the accuracy of ancient astronomical observations and calculations, but they are no evidence that the geocentric theory was correct.