Immanuel Kant (UK: /kænt/,^[20][21] US: /kɑːnt/,^[22][23] German: [ɪˈmaːnu̯eːl ˈkant];^[24][25] 22 April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers.^[26][27] Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and aesthetics have made him one of the most influential figures in modern Western philosophy.^[26][28]

In his doctrine of transcendental idealism, Kant argued that space and time are mere "forms of intuition" which structure all experience, and therefore, while "things-in-themselves" exist and contribute to experience, they are nonetheless distinct from the objects of experience. From this it follows that the objects of experience are mere "appearances" and that the nature of things as they are in themselves is unknowable to us.^[29][30] In an attempt to counter the skepticism he found in the writings of philosopher David Hume,^[31] he wrote the Critique of Pure Reason (1781/1787),^[32] his most well-known work. In it, he developed his theory of experience to answer the question of whether synthetic a priori knowledge is possible, which would in turn make it possible to determine the limits of metaphysical inquiry. Kant drew a parallel to the Copernican revolution in his proposal to think of the objects of the senses as conforming to our spatial and temporal forms of intuition, so that we have a priori cognition of those objects.^[b]

Kant believed that reason is also the source of morality, and that aesthetics arise from a faculty of disinterested judgment. Kant's views continue to have a major influence on contemporary philosophy, especially the fields of epistemology, ethics, political theory, and post-modern aesthetics.^[28] He attempted to explain the relationship between reason and human experience and to move beyond what he believed to be the failures of traditional philosophy and metaphysics. He wanted to put an end to what he saw as an era of futile and speculative theories of human experience, while resisting the skepticism of thinkers such as Hume. He regarded himself as showing the way past the impasse between rationalists and empiricists,^[34] and is widely held to have synthesized both traditions in his thought.^[35]