1. The Naturalistic System
The movement towards giving sole attention to the world of sense cannot make sure progress without a more definite decision concerning the main agents and the main direction of work. Different possibilities here offer themselves; three, however, in particular. In reality, these have all evolved, sometimes blending together and strengthening one another, at other times crossing and hindering one another.
None of these movements has displayed more energy and exercised more power than that which makes the sense experience of surrounding nature its basis, and strives to include man’s entire being within this experience. This is Naturalism, which, starting out from the mechanical conception of nature, which has been developed in the Modern Age, applies the ideas thus obtained to everything, and subordinates even the life of the soul to them. The movement originated at the dawn of the seventeenth century, when an independence and autonomy of nature began to be acknowledged. Nature had been covered with a veil of explanation, mainly æsthetic or religious in character, which gave it a colour corresponding to the prevailing disposition, but at the same time excluded the possibility of a scientific comprehension. A comprehension of this kind could only be attained by getting rid of all subjective addition which had been made by man, and by investigating nature purely by itself. Since Descartes and Galileo that has been accomplished, and nature now appears as an immense web of single threads, as a complex of fundamentally mobile, but soulless, elements, whose movements take simple basal forms, while the combination of these elements produces all constructions, even the most complicated. This mighty machinery never points beyond, and as it runs its course solely within itself, so it requires to be understood solely from itself. Everything spiritual is thus eliminated; this realm of fact has no implication of aims, or of a meaning of events.
This new scientific conception of nature had first, with much toil and difficulty, to wrestle with the traditional, naïvely human, representation; this was chiefly a matter of reducing first appearances to their simple elements, and of constructing the world anew from these. By this process, nature at the same time became accessible to the operation of man. For, the technical control of nature presupposes the analytic character of research; only such a research, with its discovery of the single elements and tendencies, places man in a relation of activity towards nature; while in earlier times only an attitude of contemplation had been granted to him. Natural Science thus created a new type of life, a life energetic, masculine, pressing forward unceasingly.
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.
Naturalism denies all independence of the spiritual life, which it regards as nothing more than an adjunct to the realm of nature, and one that can only exist along with sense existence, as a part of or as a supplement to it. Spirituality has, therefore, to subordinate itself and conform entirely to the life of nature; it can never produce and guide a movement from itself, never evolve a basal and comprehensive activity, never withdraw itself into its own sphere as into an independent realm. All self-existent spirituality fades to a world of mere shadows; whatever makes itself felt in us can only become a complete reality by winning flesh and blood through the appropriation of physical forces. Life, thus understood, possesses nothing in itself; it receives everything from its relations to the environment with which it is bound up: thought brings forth no new ideas; all ideas are merely abbreviations of sense impressions. Effort can never realise purely spiritual values; the essence of all happiness is sensuous enjoyment, however refined that may in some cases be. The naturalistic system of life receives a more definite delineation from the representation of nature, which the mechanical theory, together with a theory of descent adapted to it, sketches and impressively holds up to the present age. By this theory nature is completely resolved into a co-existence of individual forces, which, within the narrow bounds of existence, must clash violently together, and assert themselves one against the other in ceaseless conflict. This conflict, however, is a source of progressive movement, in that it brings together, establishes, and employs everything useful for self-preservation; it keeps life in a state of youthful freshness, in that new conditions continually arise and demand new accommodations with respect to the biologico-economic environment. A biologico-economic mode of thought is evolved which revolutionises all previous estimations of values. Everything intrinsically valuable disappears from the world; its expulsion seems a deliverance from a confused, indeed a meaningless, conception of things; the useful, that which promotes the interests of living beings, each after its kind, in the struggle for existence, becomes the all-dominating value. No mysterious being of things is apprehended in the True; but those presentations and systems of thought are called true which ensure that the best accommodation to the conditions of life shall be attained, and which just in this way hold the individuals together. No longer does a Good speak to man with austere demand from a transcendent sovereignty; but that is good which, within our experience, is of service to the preservation of life. The Beautiful, also, is subordinated to the useful, and it is solely by its value in