In commenting on his _Systema naturae_ he writes: “Man, know thyself; in theological aspect, that thou art created with an immortal soul, after the image of God; in moral aspect, that thou alone art blessed with a rational soul for the praise of thy sublime Creator. I ask, why did God put man equipped thus in sense and spirit on this earth, where he perceives this wonderfully ordered nature? For what, but to praise and admire the invisible Master-builder for His magnificent work.” These are the great masters and reformers of recent natural science, the men who opened up the paths which natural science of the present day is still pursuing; most of these savants were of a Christian mind, many of them even pious. There were but few indifferent or irreligious, such as _E. Halley_ (died 1742), who computed the cycle of the comet since named after him, and _G. de Buffon_ (died 1788): but they are a small minority. The period of highest achievement in modern natural science bears the stamp of religion; indeed, to a great extent it bears the halo of devotion and fervour. An incompatibility of research and faith, a solidarity of science and anti-Christian tendency, was never known to the mind of these great masters. “Any one who has grasped even the elements of natural science, the unity of natural forces and their rigid conformity to laws, becomes a monist if he has the faculty for clear reasoning, and as to the others, there is no help for them anyway” (_L. Plate_, Ultramontane Weltanschauung und moderne Lebenskunde, 1907, 11). This sort of argument is shouted at us in manifold variations. How does that statement look in the light of history? Men like _Copernicus_, _Kepler_, _Newton_, _Linné_, _Boyle_, thus knew nothing of the elements of natural science, nothing of the conformity to laws of natural forces: because they were neither monists nor atheists, but worshippers of the Creator of heaven and earth! A more painful contrast cannot be imagined than to see these great masters and pioneers rated as lesser minds, ignorant of real natural science, by those who trail far behind them and who are seeking their footsteps. The religious conviction of the natural scientists of a past age is sufficient proof that, not the research in natural science, but other causes lead minds to infidelity. Modern Times.