Neo-Kantianism

1. The back to Kant movement

With the development of experimental methods, nineteenth-century life sciences promised to provide new insights into the physical processes involved in cognition. In the eyes of thinkers such as Karl Vogt, Jacob Moleschott, Eugen Dühring, who were also practicing scientists, empirical science lent plausibility to a new form of materialism, and represented a valuable ally against the religious and metaphysical views of the romantic period. When the revival of materialism lost momentum, in the 1850s, Kant’s critical philosophy began to attract the attention of those who were interested in a philosophical investigation of the conditions of knowledge able to take into account scientific advances without replacing philosophy with empirical research. The first to call for a return to Kant to reconcile philosophy and the sciences was Hermann von Helmholtz in ‘Über das Sehen des Menschen’ [On Human Vision], a popular lecture held in 1855 in aid of the Kant Memorial at the University of Königsberg. Helmholtz argued that Kant’s theory of the a priori forms of experience had found confirmation with the discovery, in the nineteenth-century physiology of vision, of specific nerve energies preforming external stimuli. Helmholtz articulated his view further in the 1860s and 1870s by advocating a form of empiricism (also translated ‘empirism’ after Hatfield 1990), aiming to explain how some elements (i.e., the principle of causality and the forms of space and time) acquire the role of preconditions of knowledge.

Other important contributions to the rehabilitation of Kant were made in the early 1860s by philosophers with a Hegelian background, who advocated a more moderate, epistemological version of idealism (see Hegelianism). Kuno Fisher’s seminal handbook in the history of modern philosophy, from 1860, offered a reconstruction of modern thought culminating with Kant’s critical philosophy. Fisher especially appreciated Kant’s attempt to replace metaphysics and ontology with the investigation of the conditions of knowledge in the role of fundamental philosophical discipline. In a similar vein, Eduard Zeller in ‘Ueber die Bedeutung und Aufgabe der Erkenntnistheorie’ [On the Meaning and Task of the Theory of Knowledge], from 1862, connected the establishment of the theory of knowledge in nineteenth-century German philosophy with the revival of interest in Kant’s work beginning in the 1860s. The number of studies on Kant increased exponentially over the next decade, and neo-Kantianism became a dominant philosophical movement with representatives all over German universities, as documented by Köhnke (1991).

The motto ‘Back to Kant’ is derived from Otto Liebmann’s Kant und die Epigonen [Kant and the Epigones], from 1865. Liebmann’s book offered an overview of the main philosophical developments after Kant, pointing out that none of these views had been able to account for the Kantian thing in itself. Critics beginning with Friedrich Heinrich Jacobi objected that it is contradictory to assume a mind-independent object that is supposed to be beyond the limits of human experience but in causal relation with sensory experience. Liebmann’s attempt to overcome this problem was inspired by an interpretation of the Kantian philosophy in the wake of Schopenhauer, which Liebmann connected with a physiological understanding of the Kantian a priori as proposed by Helmholtz. In Liebmann’s view, this would allow one to account for the objective element of representations without falling into either idealism or materialism.

A comprehensive articulation of such a view was given by Friedrich Albert Lange in Geschichte des Materialismus und Kritik seiner Bedeutung in der Gegenwart [The History of Materialism and Criticism of Its Importance], first published in 1866 and in subsequent editions with major revisions in 1873 and 1875. After reconstructing the history of materialism from antiquity to the revival of it in the mid nineteenth century, Lange argued that Kant’s philosophy offered the most effective philosophical response to the materialists’ attempt at a reduction of all experiences to causal explanations. Kant’s analysis of the conditions of knowledge showed that such explanations are possible only in the realm of appearances, whereby the thing in itself is understood as a limiting concept. This allowed Kant to delimit the domain of scientific research rather than simply opposing metaphysical to scientific explanations. At the same time, Lange distanced himself from Kant’s assumption of unchangeable a priori forms and emphasized the need for an empirical investigation of their origins along the lines of Helmholtz’s physiological interpretation and according to the newest scientific advancements.

Several themes of Lange’s work had an important influence on the development of Cohen’s thought. This includes the interpretation of the thing in itself as a limiting concept, the appreciation of scientific advances, the idea that there is a dynamical evolution of a priori forms. However, Cohen distanced himself from the physiological interpretation of the a priori and emphasised the meta-scientific level of the transcendental investigation of the conditions of knowledge. The commitment to the transcendental inquiry marked a further development of the back to Kant movement and became the common denominator of the neo-Kantian movement.