This life, like science itself, in the first place forms a special part of a wider whole. As the expulsion of the soul from nature at first brought about a strengthening of the soul in itself, nature was the less immediately able to govern the whole. The individual of modern times strengthened and asserted himself against nature, and insisted upon a realm of independent inwardness. The contest was a severe one; yet the more nature was seen to extend, on the one hand, to the infinitely great, and, on the other, to the infinitely small, the more fixed relations it showed, so much the more overwhelmingly did it draw man to itself, the more did its conception tend to include the inner aspects of the soul also. The final blow in the struggle was given by the modern theory of descent, since this theory asserts man to be the product solely of natural forces, and maintains that everything which man ascribes to himself as characteristic and distinctive is derived from a gradual development of natural factors. And so nature is exalted as an all-comprehensive world--nature, that is, as represented in the modern mechanistic theory, which is thus transformed into a final theory of the world, a naturalistic metaphysic. The human and spiritual world, which hitherto had been felt to be an independent realm in contrast with nature, appears henceforth as its mere continuation, as something which fits completely into a wider conception of nature. A conviction of this kind must fundamentally alter the position of the spiritual life, as well as its magnitudes and values: and this conviction is no mere theory, but desires and strives to take possession of the whole of existence and to change its form completely. Indeed, a particular naturalistic type of life arises and wins a powerful influence over the thought and activity of the time.