While the literary movement of English Deism in the eighteenth century was not ostensibly grounded on physical philosophy, being rather critical and logical, it always kept the new science in view; and the movement in France, as set up by the young Voltaire, connected itself from the first with the Newtonian philosophy, which there had to drive out the Cartesian, now become orthodox. In the hands of La Mettrie biological science pointed to even deeper heresy; and for such propagandists as Diderot and D'Holbach all science was an inspiration to a general rejection of religion. Even the pursuit of mathematics developed pronounced unbelievers, such as D'Alembert and Condorcet. When, finally, in the latter half of the century the scientific spirit flagged or stagnated in England, first by reason of the new growths of industry and the new imperial expansion, later by reason of reaction against the French Revolution, it was the French men of science, in particular the astronomers and mathematicians, as Laplace, Lagrange, Lalande, and Delambre, who carried on the profession of rationalism. In particular, Laplace's great contribution, the nebular hypothesis, clinched on non-theistic grounds the whole development of modern astronomy; and the philosopher Kant, who on that point had in a measure anticipated him, never conformed to Christian orthodoxy even while glosing it in the effort to conserve theism. All the later generalizations of science have told in the same way; and all have had to struggle for life against the instinctive hostility of the Christian Churches, Protestant and Catholic alike. Geology, after generations of outcry, made an end in the nineteenth century of the orthodox theory of cosmic creation; the evolution theory drove home the negation with a new constructive doctrine; and Darwinism, after a no less desperate contest, has upturned the very foundations of Christian ethics as well as dogma. As represented by Huxley, its chief polemist, it is definitely non-Christian and non-theistic. It does not countervail this essential tendency that a number of men of science in each generation profess to adhere to Christianity. The adherence is seldom thorough, and when it is, it is commonly recognized to stand for lack of culture on the historical and ethical sides of the issue. The result is that Protestant Christianity nearly everywhere capitulates outwardly to natural science, professing still to save its own more essential dogmas; while Catholicism forces upon its adherents either "scientific nescience" or a dissimulation fatal to zeal. § 2. Philosophy, Cosmic and Moral