According to Friedrich Albert Lange[1] (1828-75; during the last years of his life professor at Marburg), materialism, which is unfruitful and untenable as a principle, a system, and a view of the world, but useful and indispensable as a method and a maxim of investigation, must be supplemented by formal idealism, which, rejecting all science from mere reason limits knowledge to the sensuous, to that which can be experienced, yet at the same time conceives the formal element in the sense world as the product of the organization of man, and hence makes objects conform to our representations. Above the sensuous world of experience and of mechanical becoming, however, the speculative impulse to construction, rounding off the fragmentary truth of the sciences into a unified picture of the whole truth, rears the ideal world of that which ought to be. Notwithstanding their indefeasible certitude, the Ideas possess no scientific truth, though they have a moral value which makes them more than mere fabrics of the brain: man is framed not merely for the knowledge of truth, but also for the realization of values. But since the significance of the Ideas is only practical, and since determinations of value are not grounds of explanation, science and metaphysics or "concept poetry" (Begriffsdichtung) must be kept strictly separate.
[Footnote 1: F.A. Lange: Logical Studies, 1877. Cf. M. Heinze in the Vierteljahrsschrift für wissenschaftliche Philosophic, 1877, and Vaihinger in the work cited above, p. 610 note.]
Friedrich Paulsen of Berlin (born in 1846; cf. pp. 330, 332, note) sees in the Kantian philosophy the foundation for the philosophy of the future. A profounder Wolff (the self-dominion of the reason), a Prussian Hume (the categories of the understanding are not world-categories; rejection of anthropomorphic metaphysics), and a German Rousseau (the primacy of the will, consideration of the demands of the heart; the good will alone, not deeds nor culture, constitutes the worth of man; freedom, the rights of man) in one person, Kant has withdrawn from scientific discussion the question concerning the dependence of reality on values or the good, which is theoretically insoluble but practically to be answered in the affirmative, and given it over to faith. Kant is in so far a positivist that he limits the mission of knowledge to the reduction of the temporo-spatial relations of phenomena to rules, and declares the teleological power of values to be undemonstrable. But science is able to prove this much, that the belief in a suprasensible world, in the indestructibility of that which alone has worth, and in the freedom of the intelligible character, which the will demands, is not scientifically impossible. Since, according to formal rationalism, the whole order of nature is a creation of the understanding, and hence atomism and mechanism are only forms of representation, valid, no doubt, for our peripheral point of view, but not absolutely valid, since, further, the empirical view of the world apart from the Idea of the divine unity of the world (which, it is true, is incapable of theoretical realization) would lack completion, the immediate conviction of the heart in regard to the power of the good is in no danger of attack from the side of science, although this can do no further service for faith than to remove the obstacles which oppose it. The will, not the intellect, determines the view of the world; but this is only a belief, and in the world of representation, the intelligible world, with which the will brings us into relation, can come before us only in the form of symbols.—While Albrecht Krause (The Laws of the Human Heart, a Formal Logic of Pure Feeling, 1876) and A. Classen (Physiology of the Sense of Sight, 1877) are strict followers of Kant, J. Volkelt (Analysis of the Fundamental Principles of Kant's Theory of Knowledge, 1879) has traced the often deplored inconsistencies and contradictions in Kant down to their roots, and has shown that in Kant's thinking, which has hitherto been conceived as too simple and transparent, but which, in fact, is extremely complicated and struggling in the dark, a number of entirely heterogeneous principles of thought (skeptical, subjectivistic, metaphysico-work, rationalistic, a priori, and practical motives) are at which, conflicting with and crippling one another, make the attainment of harmonious results impossible. Benno Erdmann (p. 330) and Hans Vaihinger (pp. 323 note, 331) have given Kant's principal works careful philological interpretation.
Among the various differences of opinion which exist within the neo-Kantian ranks, the most important relates to the question, whether the individual ego or a transcendental consciousness is to be looked upon as the executor of the a priori functions. In agreement with Schopenhauer and with Lotze, who makes the subjectivity of space, time, and the pure concepts parallel with that of the sense qualities, Lange teaches that the human individual is so organized that he must apprehend that which is sensuously given under these forms. Others, on the contrary, urge that the individual soul with its organization is itself a phenomenon, and consequently cannot be the bearer of that which precedes phenomena—space, time, and the categories as "conditions" of experience are functions of a pure consciousness to be presupposed. The antithesis of subject and object, the soul and the world, first arises in the sphere of phenomena. The empirical subject, like the world of objects, is itself a product of the a priori forms, hence not that which produces them. To the transcendental group belong Hermann Cohen[1] in Marburg, A. Stadler[2], Natorp, Lasswitz (p.17), E. König (p. 17), Koppelmann (p. 330), Staudinger (p. 331). Fritz Schultze of Dresden is also to be counted among the neo-Kantians (Philosophy of Natural Science, 1882; Kant and Darwin, 1875; The Fundamental Thoughts of Materialism, 1881; The Fundamental Thoughts of Spiritualism, 1883; Comparative Psychology, i. 1, 1892).
[Footnote 1: Cohen: Kant's Theory of Experience, 1871, 2d ed., 1886; Kant's Foundation of Ethics, 1877; Kant's Foundation of Aesthetics, 1889.]
[Footnote 2: Stadler: Kant's Teleology, 1874; The Principles of the Pure
Theory of Knowledge in the Kantian Philosophy, 1876; Kant's Theory of
Matter, 1883.]
The German positivists[1]:—E. Laas of Strasburg (1837-85), A. Riehl of Freiburg in Baden (born 1844), and R. Avenarius of Zurich (born 1843)—develop their sensationalistic theory of knowledge in critical connection with Kant. Ernst Laas defines positivism (founded by Protagoras, advocated in modern times by Hume and J.S. Mill, and hostile to Platonic idealism) as that philosophy which recognizes no other foundations than positive facts (i.e., perceptions), and requires every opinion to exhibit the experiences on which it rests. Its basis is constituted by three articles of belief: (1) The correlative facts, subject and object, exist and arise only in connection (objects are directly known only as the contents of a consciousness, cui objecta sunt, subjects only as centers of relation, as the scene or foundation of a representative content, cui subjecta sunt: outside my thoughts body does not exist as body, nor I myself as soul). (2) The variability of the objects of perception. (3) Sensationalism—all specific differences in consciousness must be conceived as differences in degree, all higher mental processes and states, including thought, as the perceptions and experiences, transformed according to law, of beings which feel, have wants, possess memory, and are capable of spontaneous motion. The subject coincides with its feeling of pleasure and pain, from which sensation is distinguished by its objective content. The illusions of metaphysics are scientifically untenable and practically unnecessary. Various yearnings, wants, presentiments, hopes, and fancies, it is true, lead beyond the sphere of that which can be checked by sense and experience, but for none of their positions can any sufficient proof be adduced. As physics has discarded transcendent causes and learned how to get along with immanent causes, so ethics also must endeavor to establish the worth of moral good without excursions into the suprasensible. The ethical obligations arise naturally from human relations, from earthly needs. The third volume of Laas's work differs from the earlier ones by conceding the rank of facts to the principles of logic as well as to perception. Aloys Riehl opposes the theory of knowledge (which starts from the fundamental fact of sensation) as scientific philosophy to metaphysics as unscientific, and banishes the doctrine of the practical ideals from the realm of science into the region of religion and art. Richard Avenarius defends the principle of "pure experience." Sensation, which is all that is left as objectively given after the removal of the subjective additions, constitutes the content, and motion the form of being.
[Footnote 1: Laas: Idealism and Positivism, 1879-84. Riehl: Philosophical Criticism, 1876-87; Address On Scientific and Unscientific Philosophy, 1883. Avenarius (p. 598): Philosophy as Thought concerning the World according to the Principle of Least Work, 1876; Critique of Pure Experience, vol. i. 1888, vol. ii. 1890; Man's Concept of the World, 1891. C. Göring (died 1879; System of Critical Philosophy, 1875) may also be placed here.]
With the neo-Kantians and the positivists there is associated, thirdly, a coherent group of noëtical thinkers, who, rejecting extramental elements of every kind, look on all conceivable being as merely a conscious content. This monism of consciousness is advocated by W. Schuppe of Greifswald (born 1836; Noëtical Logic, 1878), J. Rehmke, also of Greifswald (The World as Percept and Concept, 1880; "The Question of the Soul" in vol. ii. of the Zeitschrift für Psychologie, 1891), A. von Leclair (Contributions to a Monistic Theory of Knowledge, 1882), and R. von Schubert-Soldern (Foundations of a Theory of Knowledge, 1884; On the Transcendence of Object and Subject, 1882; Foundations for an Ethics, 1887). J. Bergmann[1] in Marburg (born 1840) occupies a kindred position.
[Footnote 1: Bergmann: Outlines of a Theory of Consciousness, 1870; Pure
Logic, 1879; Being and Knowing, 1880; The Fundamental Problems of
Logic, 1882; On the Right, 1883; Lectures on Metaphysics, 1886; On
the Beautiful, 1887; History of Philosophy, vol. i., Pre-Kantian
Philosophy, 1892.]