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 believed that previous philosophers had neglected synthetic a priori judgments, and had paid attention only to analytic a priori and synthetic a posteriori judgments. David Hume, for example, believed that all knowledge is either of "relations of ideas" (which are analytic a priori) or "matters of fact" (which are synthetic a posteriori). Hume's taxonomy excludes the synthetic a priori. But by establishing the synthetic a priori as a third kind of judgment, Kant believes we can push back against Hume's skepticism about such matters as causation and metaphysical knowledge more generally. This is because, unlike merely a posteriori judgments, a priori judgments have "true or strict ... universality" and includes a claim of "necessity". And, unlike merely analytic claims, synthetic judgements extend our knowledge beyond the subject concept. This means that showing how synthetic a priori judgments are possible amounts to showing how substantive knowledge about necessary features of the world is possible. Kant himself regards it as uncontroversial that we do have synthetic a priori knowledge—especially in mathematics. Consider the proposition '7 + 5 = 12'. Kant claims that the concept of '12' is not contained in the concepts of '5', '7', and the addition operation. Yet, although he considers the possibility of such knowledge to be obvious, Kant nevertheless assumes the burden of showing how such synthetic a priori knowledge in mathematics and the natural sciences is possible, and attacks, in the Transcendental Dialectic, the possibility of synthetic a priori knowledge of traditional metaphysics. It is the twofold aim of the Critique both to prove and to explain the possibility of this knowledge. Kant says "There are two stems of human cognition, which may perhaps arise from a common but to us unknown root, namely sensibility and understanding, through the first of which objects are given to us, but through the second of which they are thought." Kant's term for the object of sensibility is 'intuition', and his term for the object of the understanding is 'concept'. In general terms, the former is a non-discursive representation of a particular object, and the… What…