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Rehmke, Johannes (1848–1930)


Johannes Rehmke, the German epistemologist, ontologist, and ethical philosopher, was born at Elmshorn in Schleswig-Holstein. He studied evangelical theology and philosophy at Kiel and Zürich from 1867 to 1871, receiving his doctorate in philosophy at Zürich in 1873. After some years as a high school teacher at St. Gallen, Rehmke was appointed unsalaried lecturer in philosophy at the University of Berlin in 1884. The following year he became professor of philosophy at the University of Greifswald, where he taught until 1921.

Theory of Knowledge

Rehmke did not assume the existence of two worlds: a world, only indirectly knowable, of transsubjective objects, and an immediately knowable world, with intrasubjective perceptions and the like as contents. Rather, he asserted the existence of directly knowable real objects. This epistemological monism was a consequence of his ontological dualism of two essentially different kinds of being. Physical (material) beings are spatially extended and occupy a place; mental (immaterial) beings are not extended and have no place.

The nonspatial, placeless character of consciousness conflicts with the uncritical application to the subject of such concepts as "in" and "external," as exemplified in such terms as "intrasubjective" and "transsubjective"in other words, "immanent" and "transcendent," or "content of consciousness" and "external object." Not only does consciousness not involve the having of a content; it does not involve any kind of having by means of a relation, in any event one that presupposes the existence of at least two realities separated from one another. On the contrary, knowing without any relation between diverse things is possible from the outset, as can be seen in self-consciousness. In self-consciousness only one thing is given, the particular knowing consciousness as knowing itself and as being known by itself. Thus, Rehmke's proposition "Knowing is having without a relation" expresses the immediacy of all knowledge, including knowledge of the so-called external world, the world of objects outside the body.

In his Logik oder Philosophie als Wissenslehre (Leipzig, 1918), Rehmke sought to demonstrate the importance of the general or universal for the movement of knowledge toward clarity. In accord with his proof of the immediacy of cognition, he rejected as false the notion that thinking is an internal, that is, intramental, activity and even rejected the notion of thought activity because the purported activity never produces a change in objects. Thinking is not a "doing" but a "finding." If, for example, someone makes the judgment "A boiled crayfish is red," this observation signifies that he as thinker finds anew in the object the red known before. What is thus discovered in the object is never something single, an individual being, but something repeated, a universal.

Because the universal forms part of each particular object, it is something objective. If red is found in the crayfish, the logical subject of the judgment is not simply "(boiled) crayfish," but "red boiled crayfish." Consequently, every judgment, with respect to the universal discovered in the particular object, is logically analytic. Grammatically, with regard to the joining of the linguistic signs into a sentence, it is synthetic.

In its function as predicate of a judgment, an objective universal is called a concept. Every concept is thus a universal. Because of its objectivity, the universal as concept, despite its relation to the thinking subject, cannot be merely subjective. It is equally erroneous to confuse or to equate the concept, which is always bound up with a particular word, with that word, that is, with the phonic structure as linguistic sign.

The objectivity of the universal as a possible concept reveals the error in the phrase "concept formation." A concept (for example, "tree") is not first constructed by comparing several objects (for example, pines, beeches, and alders) by means of an "internal activity" of thought. The concept is presupposed in the very selection of objects of the same kind. Concept formation is really conceptual clarification, the determination of which characteristics in union constitute a concept already given. Clarity is the guiding notion in Rehmke's logic. He claimed that, in any deepening of knowledge, the universal as logical predicate helps consciousness to obtain clarity, and ultimately unquestionable clarity.

Rehmke's conception of logic, that is, philosophy as theory of knowledge, is linked with his notion of philosophy as fundamental science, expressed in his Philosophie als Grundwissenschaft (Frankfurt, 1910). Both theory of knowledge and fundamental science are genuine sciences, directed toward that which is simply given, that is, toward objects regardless of their being real or unreal. They are also in equal measure philosophy because they deal with the totality of the given, in contrast with the particular sciences, each of which deals with only a particular section of the world. Theory of knowledge deals with the given as that which is thought (known); fundamental science deals with it in regard to its most universal character. But while logic presupposes the concept "universal," and each special science presupposes its own fundamental concepts, the task of philosophy as fundamental science is to elucidate without prejudice precisely the basic "that which is most universal."

The Traditional Ontology

Theory of knowledge is not a fundamental science. Historically, it arose from an epistemological dualism, and as a consequence its form is faulty. In any case, it must presuppose the basic distinction between knower and other. Rehmke's painstaking ontological studies in Philosophie als Grundwissenschaft of the manifold "most universal" embrace five paired notions: (1) matter and consciousness, (2) the universal and the unique, (3) unity and simplicity, (4) the changeable and the unchangeable, (5) the real and the unreal. For Rehmke, of course, the first pair was primary. Beyond the merely negative descriptionimmaterial, nonspatial, and place-lessthe essence of the mental is completely determined by the concept of consciousness, or knowledge. Rehmke therefore opposed both materialism and idealism (spiritualism), as well as Spinozism.

Everything without exception proves to be either a unique thing (something that occurs only once, such as a unique tree) or a universal (something that is repeated, such as green or "treeness"). It follows that the unique and the universal do not exist without each other; indeed, objectively the universal belongs to the unique. Rehmke classified the unique into individuals (for example, individual trees) and units of individuals. He divided the latter into operational units (for example, an auto with a trailer) and living units (for example, a state). The universal is either a determination (such as angularity) or a relation (such as similarity). Rehmke attached great value to his recognition that many seemingly ontological concepts, such as space, time, being, and value, are merely relational ones.

In connection with the third of his five pairs, unity and simplicity, Rehmke distinguished between individuals that are composed of individuals (and hence are ephemeral, passing) and individuals that are absolutely simple (and hence are everlasting). Examples of the latter are elementary particles and consciousness. Denying the theory of substance, he held that the individual is a union of its determinations (a body, for instance, is a union of size, shape, and location). He also analyzed each specific determination into determination as such (for instance, shape as such) and particularity.

Rehmke equated the fourth relationship, the changeable and the unchangeable, with the distinction between individual and universal. In this context he pointed out that the concept of change refers only to exchange of individual characteristics, with the determination as such (for instance, the shape as such) remaining the same.

Rehmke treated in detail the relationship between the real and the unreal. He defined the real as consisting in relationship of action. This enabled him to do justice to such properties of things as sweetness, which are often dismissed as merely subjective.

Psychology and Ethics

In his Lehrbuch der Allgemeinen Psychologie (Frankfurt, 1894), Rehmke stressed that human consciousness (mind) is a simple, immaterial individual being, in a constant unity of action with an essentially different body. Thus, man is not a "double-beinged" individual. There are four general characteristics of consciousness: (1) determination of objects, each one directly perceived or imagined, even though the perception is mediated by the sense organs; (2) states (conditions), for example, delight or listlessness; (3) thoughteither distinguishing (being aware of the distinct) or uniting (awareness of unity); (4) the subject, the determination of which establishes at the same time the unity of the ego. These determinations are not to be construed as mental activities.

Because of its intermittent character, volition, despite its relations with the above determinations, is not one of them. Rehmke's analysis of volition aided him in his solution of the problem of free will. He separated the problem into four parts, each of which is answerable: (1) Is an act of the will prevented or not? (2) Is the volition random or conditioned? (3) Is there a genuine possibility of choice, or is the will constrained? (4) Is the volition freely self-determined or not?

Rehmke's theory of the will constitutes the background for his ethics. He distinguished five forms of ethicsfour false and one genuine. The ethics of shrewdness has to do with men "for themselves." The ethics of the unity of control expresses duty as an "ought." The ethics of the unity of life expresses duty as a "must" and comprises the ethics of society (in which unity as "being with one another" is a means to a selfish end) and the ethics of community (in which unity as "being for one another" is an end in itself). Finally, separating the merely social from the moral proper is the ethics of selfless love of one person as such "for another," arising from his knowledge of himself as at one with the other.

See also Being; Consciousness; Determinism and Freedom; Epistemology; Ethics, History of; Idealism; Knowledge and Belief; Matter; Ontology, History of.


additional works by rehmke

Unsere Gewissheit von der Aussenwelt (Our certainty about the external world). Heilbronn, 1892.

Grundlegung der Ethik als Wissenschaft (Foundations of ethics as a science). Leipzig: Quelle and Meyer, 1925.

Die Willensfreiheit (The freedom of the will). Leipzig, 1925.

Gesammelte philosophische Aufsätze (Collected philosophical essays). Edited by Kurt Gassen. Erfurt: K. Stenger, 1928.

"Selbstdarstellung." In Die Philosophie der Gegenwart in Selbstdarstellung, edited by Raymund Schmidt, 7 vols., Vol. I, 177200. Leipzig, 19211929.

For a full bibliography see Grundwissenschaft. Philosophische Zeitschrift der Johannes-Rehmke-Gesellschaft 1 (1919): 7288, and 10 (1931): 3644.

works on rehmke

Heyde, J. E. Grundwissenschaftliche Philosophie. Leipzig, 1924.

Heyde, J. E. "Johannes Rehmke." Grundwissenschaft. Philosophische Zeitschrift der Johannes-Rehmke-Gesellschaft 10 (1931): 135.

Heyde, J. E. "Johannes Rehmke." Zeitschrift für philosophische Forschung (1947): 603606.

Heyde, J. E. "Johannes Rehmke 18481930." Philosophische Studien 2 (1951): 260271.

"Johannes Rehmke." In Grundriss der Geschichte der Philosophie, edited by F. Schneider, 319329. Bonn, 1959.

Joh's Erich Heyde (1967)

Translated by Albert E. Blumberg

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