But in another sense, nature is, not indeed the opposite of spirit, but something distinct in the spirit, and especially distinct from the cognitive spirit, as that form of spirituality and activity which is not cognitive. A non-theoretical activity, a spirituality which should not be in itself knowledge, cannot be anything but the practical form of the spirit, the will. Man makes himself nature at every moment, because at every moment he passes from knowing to willing and doing and from willing and doing returns to knowing, which is the basis for new will and action. In this sense, the science of nature, or the philosophy of nature, could not be anything but the philosophic science of the will, the Philosophy of the practical.
Nature in the gnoseological sense, as naturalistic or empirical method.
The natural sciences have nothing to do with a philosophic knowledge of nature as will, with a Philosophy of the practical. They are, as has already been said, not knowledge of will, but will; not truth, but utility. In consequence of this, they extend to the whole of reality, theoretic and practical, to the products of the theoretic spirit, not less than to those of the practical spirit; and without knowing any of them, universally or individually, they manipulate and classify them all in the way we have seen. They have not therefore a special object, but a special mode of treatment, their object or matter being the presupposed philosophic-historical knowledge of the real. They do not treat of the material and mechanical aspect of the real, nor even of its non-theoretical, practical, volitional aspect (or what is incorrectly called the irrational aspect of it). They turn the theoretical into the practical, and by killing its theoretic life, make it dead, material, and mechanical. Nature, matter, passivity, motion ab extra, the inert atom and so on, are not reality and concepts, but natural science itself in action. Mechanism, logically considered, is neither a fact nor a mode of knowing the fact. It is a non-fact, a mode of not-knowing: a practical creation, which is real only in so far as it becomes itself an object of knowledge. This is the gnoseological or gnoseopractical meaning of the word "nature," a meaning which must be kept carefully distinct from the two preceding meanings. When we speak, for instance, of matter or of nature as not existing, we mean to refer to the puppet of the naturalists, which the naturalists themselves and the philosophers of naturalism, forgetting its genesis, take for a real if not a living being. That matter (said Berkeley) is an abstraction; it is (say we) an empirical concept, and whoever knows what empirical concepts are will not pretend that matter or nature exists, simply because it is spoken about.
The illusions of materialists and dualists.
We do not claim to have supplied the full solution of the problem concerning the dualism or materialism of the real with this discussion on the theme of Logic. This solution cannot (we repeat) be expected, save from all the philosophic sciences together, that is to say, from the complete system. But we can already see, from the logical point of view, that the dualists and materialists cannot avoid the task of showing that the nature or matter, which they elevate to a principle of the real or to one of the two principles of the real, is not: firstly, the mere negation of the spirit, nor secondly, a form of the spirit, nor thirdly, the abstraction of the natural sciences. They must also show that it answers to something conceivable and existing, outside or above the spirit. Logic can pass onward at this point, saying of materialists and dualists what Dante said of the devils and the damned struggling in the lake of burning pitch: "And we leave them thus encompassed."
Nature as empirical distinction of an inferior in relation to a superior reality.
The word "nature" has yet a fourth meaning (but this time altogether empirical), which is clear in those propositions which distinguish natural life from social life, natural men (Naturmenschen) or savages from civilized men, and again natural from human beings, animals from men, and so on. Nature, in this sense, is distinguished from civilization or humanity, and thus the sole reality is divided into two classes of beings: natural beings and human beings (which are sometimes also called spiritual as compared with the former, which are called material). The vague and empirical nature of this distinction is at once perceived from the impossibility that we meet with of assigning boundaries between civilization and the state of nature, between humanity and animality. Man can be only empirically distinguished from the animal, the animal from the vegetable, and vegetables from inorganic beings, which are organic in their own way. Certainly, what are called things are not organic, for example a mountain or a plough-share; but they are not organic, because they are not real, but aggregates, that is to say, empirical concepts. In the same way, a forest is not organic, though it is composed of things vegetating, nor a crowd, though composed of men. When we treat of things in the above sense, we can say with some mathematicians that things do not exist, but only their relations. Hence if the dualists feel able to affirm that the two classes of beings, natural and human, are based upon the existence of two different substances and upon the different proportions of these in each of the two classes, the task of proving the thinkability of the two substances and the different proportions of the compound falls upon them.
The naturalistic method and the natural sciences as extended to superior not less than to inferior reality.
The distinction between nature and spirit being therefore, in this last sense, altogether empirical, it is clear that the natural sciences (in the gnoseological or gnoseopractical sense in which we give chem this name) are not restricted to the development of knowledge relating to what is called inferior reality, from the animal downwards, leaving to the sciences of the spirit the knowledge that relates to superior reality from the animal upwards, that is to say, to man. Sciences of nature and sciences of the spirit, orbis naturalis and orbis intellectuals, are also, in this case, partitions and convenient groupings. All do substantially the same thing, that is to say, they provide one single homogeneous practical treatment of knowledge.
Demand for such an extension, and effective existence of what is demanded.