Immanuel Kant (born Emanuel Kant; 22 April 1724 – 12 February 1804) was a German philosopher. Born in Königsberg in the Kingdom of Prussia, he is considered one of the central thinkers of the Enlightenment. His comprehensive and systematic works in epistemology, metaphysics, logic, ethics, aesthetics, political theory, and the philosophy of religion have made him one of the most influential and hi Kant's 1781 (revised 1787) Critique of Pure Reason has often been cited as the most significant volume of metaphysics and epistemology in modern philosophy. In the first Critique, and in later works as well, Kant frames the "general" and "real problem of pure reason" in terms of the following question: "How are synthetic judgments a priori possible?" To understand this claim, it is necessary to define some terms. First, Kant makes a distinction between two sources of knowledge: Kant's philosophy attracted considerable attention during his lifetime. Karl Leonhard Reinhold helped popularize the critical philosophy through a series of public letters published beginning in 1786. Kant's ideas were subsequently taken up and transformed by Johann Gottlieb Fichte, Friedrich Wilhelm Joseph Schelling, Georg Wilhelm Friedrich Hegel, and other figures associated with German idealism. These philosophers generally accepted Kant's claim that the knowing subject makes an active contribution to experience, but disputed the limits he placed upon philosophical knowledge. Fichte attempted to derive the structures of experience from the activity of self-consciousness, while Schelling and Hegel sought to overcome Kant's divisions between subject and object, freedom and nature, and thought and reality. Hegel was both one of Kant's most influential successors and one of his most important critics. He objected to treating the transcendental subject apart from the historical and social life of concrete individuals. He also criticized Kantian morality for appearing too formal and abstract, contras He first attended the Collegium Fridericianum (then directed by Franz Albert Schultz), from which he graduated at the end of the summer of 1740. In 1740, aged 16, he enrolled at the University of Königsberg, where he would later remain for the rest of his professional life. He studied the philosophy of Gottfried Leibniz and Christian Wolff under Martin Knutzen (Associate Professor of Logic and Metaphysics from 1734 until he died in 1751), a rationalist who was also familiar with developments in British philosophy and science and introduced Kant to the new mathematical physics of Isaac Newton. In December 1758, after the death of Johann David Kypke, Kant petitioned Empress Elizabeth for appointment to the vacant chair of logic and metaphysics at the University of Königsberg, but the position was awarded to another candidate. == Early work == Kant is best known for his work in the philosophy of ethics and metaphysics, but he also contributed significantly to other disciplines. In 1754, while contemplating a prize question by the Berlin Academy about the problem of Earth's rotation, he argued that the Moon's gravity would slow down the Earth's spin. He also put forth the argument that gravity would eventually cause the Moon's tidal locking to coincide with the Earth's rotation. Kant's reputation gradually rose through the latter portion of the 1780s, sparked by a series of important works: the 1784 essay, "Answer to the Question: What is Enlightenment?"; 1785's Groundwork of the Metaphysics of Morals (his first work on moral philosophy); and Metaphysical Foundations of Natural Science from 1786. Kant's fame ultimately arrived from an unexpected source. In 1786, Karl Leonhard Reinhold published a series of public letters on Kantian philosophy. In these letters, Reinhold framed Kant's philosophy as a response to the central intellectual controversy of the era: the pantheism controversy. He also criticized Kantian morality for appearing too formal and abstract, contrasting it with the institutions, customs, and relationships of what he called ethical life. Nevertheless, Hegel retained Kant's concern with freedom and continued Kant's attempt to understand freedom as more than the satisfaction of individual desires. Kant Otto Liebmann's Kant und die Epigonen (1865), which repeatedly urged a “return to Kant”, helped initiate the movement later known as neo-Kantianism. Neo-Kantian philosophers reworked Kant's critical method in response to developments in the natural sciences, the human sciences, logic, and theories of knowledge. Kant's philosophy of mathematics also remained influential. He held that mathematical judgments were synthetic a priori and depended upon the pure intuitions of space and time. Although later mathematics challenged parts of this account, Kant's emphasis on mathematical construction and intuition influenced debates in the philosophy of mathematics, including the development of intuitionism. === Twentieth-century philosophy === Kant's influence continued across several major traditions of twentieth-century philosophy. His account of the conditions of possible experience contributed to the development of phenomenology, while his concepts of autonomy, reason, and critique remained important for critical theory. His philosophy also influenced debates in existentialism, the philosophy of language, and the philosophy of mind. The Chinese philosopher Mou Zongsan translated Kant's three Critiques and developed his own form of New Confucianism through an extended engagement with Kant's accounts of moral autonomy, intellectual intuition, and human nature. Kant's ideas have also been discussed in psychology, sociology, cognitive science, and the philosophy of science. His account of the unity of consciousness remains relevant to debates in the philosophy of mind, while his conception of the active organization of experience has been compared with later theories in developmental psychology and cognitive science.