Since thus Protestantism sprang from the essence of the same spirit in which modern philosophy had its birth, the two have the closest relation to each other, though of course there is a specific difference between the religious and the scientific principle. Yet in their origin, both kinds of Protestantism, that of religion and that of thought, are one and the same, and in their progress they have also gone hand in hand together. For religion, reduced to its simple elements, will be found to have its source, like philosophy, in the self-knowledge of the reason.
5. THE ADVANCEMENT OF THE NATURAL SCIENCES.—To all these phenomena, which should be regarded both as causes and as symptoms of the intellectual revolution of this period, we must add yet another, which essentially facilitated and gave a positive assistance to the freedom of the mind from the fetters of authority—the starting up of the natural sciences and the inductive method of examining nature. This epoch was a period of the most fruitful and influential discoveries in nature. The discovery of America and the passage to the East Indies had already widened the circle of view, but still greater revolutions are connected with the name of a _Copernicus_ (died 1543), _Kepler_ (died 1630), and _Galileo_ (died 1642), revolutions which could not remain, without an influence upon the whole mode of thinking of that age, and which contributed prominently to break the faith in the prevailing ecclesiastical authority. Scholasticism had turned away from nature and the phenomenal world, and, blind towards that which lay before the very eyes, had spent itself in a dreamy intellectuality; but now nature rose again in honor; her glory and exaltation, her infinite diversity and fulness of life became again the immediate objects of observation; to investigate nature became an essential object of philosophy, and scientific empiricism was thus regarded as a universal and essential concern of the thinking man. From this time the natural sciences date their historical importance, for only from this time have they had an uninterrupted history. The results of this new intellectual movement can be readily estimated. Such a scientific investigation of nature not only destroyed a series of traditional errors and prejudices, but, what was of greater importance, it directed the intellectual interest towards that which is real and actual, it nourished and protected the self-thinking and feeling of self-dependence, the spirit of inquiry and proof. The standpoint of observation and experiment presupposes an independent self-consciousness of the individual, a breaking loose from authority—in a word, scepticism, with which, in fact, the founders of modern philosophy, _Bacon_ and _Descartes_, began; the former by conditioning the knowledge of nature upon the removal of all prejudice and every preconceived opinion, and the latter by demanding that philosophy should be begun with universal doubt. No wonder that a bitter struggle should soon break out between the natural sciences and ecclesiastical orthodoxy, which could only result in breaking the power of the latter.