The historical process of development is definitively marked out through this focus on the environing world. Even the hastiest glance at the corporeality present in the environing world shows that nature is a homogeneous, unified totality, a world for itself, so to speak, surrounded by a homogeneous spatiotemporality and divided into individual things, all similar in being res extensae and each determining the other causally. Very quickly comes a first and greatest step in the process of discovery: overcoming the finitude of nature that has been thought of as objective-in-itself, finitude in spite of the open infinity of it. Infinity is discovered, and first of all in form of idealized quantities, masses, numbers, figures, straight lines, poles, surfaces, etc. Nature, space and time become capable of stretching ideally into infinity and also of being infinitely divided ideally. From the art of surveying develops geometry; from counting, arithmetic; from everyday mechanics, mathematical mechanics; etc. Now, without anyone forming a hypothesis in this regard, the world of perceived nature is changed into a mathematical world, the world of mathematical natural sciences. As ancient times moved forward, with the mathematics proper to that stage, the first discovery of infinite ideals and of infinite tasks was accomplished simultaneously. That discovery becomes for all subsequent times the guiding star of the sciences.
How, then, did the intoxicating success of this discovery of physical infinity affect the scientific mastery of the realm of spirit? In the focus on the environing world, a constantly objective attitude, everything spiritual appeared to be based on physical corporeality. Thus an application of the mode of thought proper to natural science was obvious. For this reason we already find in the early stages Democritean materialism and determinism.47 However, the greatest minds recoiled from this and also from any newer style of psychophysics. Since Socrates, man is made thematic precisely as human, man with his spiritual life in society. Man retains an orientation to the objective world, but with the advent of Plato and Aristotle this world becomes the great theme of investigations. At this point a remarkable cleavage makes itself felt: the human belongs to the universe of objective facts, but as persons, as egos, men have goals, aims. They have norms for tradition, truth norms – eternal norms. Though the development proceeded haltingly in ancient times, still it was not lost. Let us make the leap to so-called “modern” times. With glowing enthusiasm the infinite task of a mathematical knowledge of nature and in general of a world knowledge is undertaken. The extraordinary successes of natural knowledge are now to be extended to knowledge of the spirit. Reason had proved its power in nature. “As the sun is one all-illuminating and warming sun, so too is reason one” (Descartes).48 The method of natural science must also embrace the mysteries of spirit. The spirit is real49 and objectively in the world, founded as such in corporeality. With this the interpretation of the world immediately takes on a predominantly dualistic, i.e., psychophysical, form. The same causality -only split in two- embraces the one world; the sense of rational explanation is everywhere the same, but in such a way that all explanation of spirit, in the only way in which it can be universal, involves the physical. There can be no pure, self-contained search for an explanation of the spiritual, no purely inneroriented psychology or theory of spirit beginning with the ego in psychical self-experience and extending to the other psyche.50 The way that must be traveled is the external one, the path of physics and chemistry. All the fond talk of common spirit, of the common will of a people, of nations’ ideal political goals, and the like, are romanticism and mythology, derived from an analogous application of concepts that have a proper sense only in the individual personal sphere. Spiritual being is fragmentary. To the question regarding the source of all these difficulties the following answer is to be given: this objectivism or this psychophysical interpretation of the world, despite its seeming self-evidence, is a naÎve one-sidedness that never was understood to be such. To speak of the spirit as reality (Realitat), presumably a real (realen) annex to bodies and having its supposedly spatiotemporal being within nature, is an absurdity.