is an orthodoxy in science, as hard to define perhaps, but just as clearly recognized, as in matters of religion. In mathematics the true faith lies on this side of circle-squaring. In geology cataclysms and all the powers of Pluto are renounced by the true believer. In biology it has come to pass that he who takes in vain the name of Darwin and scoffs at the doctrine of evolution is held to be without the pale; he is no longer to be reasoned with as a mere erring brother, he is to be treated with silent pity as one beyond hope. In astronomy the current heresies are few and feeble; the catchpenny paradoxes of Mr. Parallax, the wagering Ptolemaisms of Mr. Hampden, the looking-glass theories of Mr. Brett are typical of the rest. The fierce discussions which enliven the meetings of the Astronomical Society are generally concerned with the constitution of the committee, not of the sidereal universe. In chemistry, on the other hand, so little is settled, or rather so much is being unsettled, that no fixed creed or general confession can long unite any large body of its professors. The air is full of a vague expectation; the transmutation of the metals is no longer a chimera to be banned. We may wake any morning to find it a thing accomplished. And yet the priesthood have an air of standing on the defensive. They give a faint welcome to Meyer when he proclaims that chlorine is not so simple as it seemed. They mutter that Lockyer is "no chemist," and that his sources are impure, when he sets at naught the received doctrine of the spectrum, and seems to show that the metals are not many and diverse, but few and kindred.
Physics is happier than some of these sciences in having one cardinal formula by which at once a world of heresies may be tested; it is written that "the perpetual motion is impossible." This is no mere negation; rightly understood it is a mighty instrument for the gaining of new truth, as well as for the quelling of old error. The undevout philosopher who openly contemns it defines his own position unmistakably; he is "miscreant" in the old sense; he is shut out from the fellowship of the faithful. But some accept the dogma in words, while their works belie their belief in it. Even in this Christian land it is said that some who assent with their lips to all the creeds and all the articles, to whom no test is distasteful, do yet in their lives exhibit small regard for the things they have professed. On the other hand there are some who glory in the name of heretic, and yet in all men’s eyes live lives of goodness and do the deeds of virtue. Such phenomena as these are apt to perplex the honest Churchman in his attempts to limit his sympathies by the letter of his creed. He is fain to fashion strange theories of grace and gracelessness, or to waver painfully between universalism and intolerance. In physical science it is not wonderful if similar difficulties are felt at times by the official guardians of sound doctrine. Long ago these worthies were almost inclined to doubt the existence or the wisdom of Providence when they contemplated the grand discoveries of Kepler, and his fantastic and preposterous theories. "His success may well inspire with dismay those who are accustomed to consider experiment and rigorous induction as the only means to interrogate nature with success," thus the "Useful Knowledge" history of astronomy. His biographer, again, talks of "Kepler’s good fortune in seizing truths across the wildest and most absurd theories." As Whewell well remarks, these writers "seem to have been alarmed at the moral that their readers might draw from the tale of a 'quest of knowledge,' in which the hero, though fantastical and self-willed, and violating in his conduct, as they conceived, all right rule and sound philosophy, is rewarded by the most signal triumphs."