section_path: Influence and legacy/Historical influence
section_name: Historical influence
paragraph_text: Historical influence
  
  During his own life, much critical attention was paid to Kant's thought. He influenced Reinhold, Fichte, Schelling, Hegel, and Novalis during the 1780s and 1790s. Samuel Taylor Coleridge was greatly influenced by Kant and helped to spread awareness of him, and of German Idealism generally, in the UK and the US. In his Biographia Literaria (1817), he credits Kant's ideas in coming to believe that the mind is not a passive, but an active agent in the apprehension of reality. Hegel was one of Kant's first major critics. In Hegel's view the entire project of setting a "transcendental subject" (i.e., human consciousness) apart from the living individual as well as from nature, history, and society was fundamentally flawed, although parts of that very project could be put to good use in a new direction. Similar concerns motivated Hegel's criticisms of Kant's concept of moral autonomy, to which Hegel opposed an ethic focused on the "ethical life" of the community. In a sense, Hegel's notion of "ethical life" is meant to subsume, rather than replace, Kantian ethics. And Hegel can be seen as trying to defend Kant's idea of freedom as going beyond finite "desires", by means of reason. Thus, in contrast to later critics like Nietzsche or Russell, Hegel shares some of Kant's concerns.
  
  Kant's thinking on religion was used in Britain by philosophers such as Thomas Carlyle to challenge the nineteenth-century decline in religious faith. British Catholic writers, notably G. K. Chesterton and Hilaire Belloc, followed this approach. Criticisms of Kant were common in the realist views of the new positivism at that time. Arthur Schopenhauer was strongly influenced by Kant's transcendental idealism. Like G. E. Schulze, Jacobi, and Fichte before him, Schopenhauer was critical of Kant's theory of the thing-in-itself. Things-in-themselves, they argued, are neither the cause of what we observe, nor are they completely beyond our access. Ever since the Critique of Pure Reason, philosophers have been critical of Kant's theory of the thing-in-itself. Many have argued that, if such a thing exists beyond experience, then one cannot posit that it affects us causally, since that would entail stretching the category "causality" beyond the realm of experience.
  
  With the success and wide influence of Hegel's writings, Kant's own influence began to wane, but a re-examination of his ideas began in Germany in 1865 with the publication of Kant und die Epigonen by Otto Liebmann, whose motto was "Back to Kant". There proceeded an important revival of Kant's theoretical philosophy, known as Neo-Kantianism. Kant's notion of "critique" has been more broadly influential. The early German Romantics, especially Friedrich Schlegel in his "Athenaeum Fragments", used Kant's reflexive conception of criticism in their Romantic theory of poetry. Also in aesthetics, Clement Greenberg, in his classic essay "Modernist Painting", uses Kantian criticism, what Greenberg refers to as "immanent criticism", to justify the aims of abstract painting, a movement Greenberg saw as aware of the key limitation—flatness—that makes up the medium of painting. French philosopher Michel Foucault was also greatly influenced by Kant's notion of "critique" and wrote several pieces on Kant for a re-thinking of the Enlightenment as a form of "critical thought". He went so far as to classify his own philosophy as a "critical history of modernity, rooted in Kant".
  
  Kant believed that mathematical truths were forms of synthetic a priori knowledge, which means they are necessary and universal, yet known through the a priori intuition of space and time, as transcendental preconditions of experience. Kant's often brief remarks about mathematics influenced the mathematical school known as intuitionism, a movement in philosophy of mathematics opposed to Hilbert 's formalism, and Frege and Bertrand Russell 's logicism.