Kant, Immanuel: - "One of the key figures in the Enlightenment was the German philosopher Immanuel Kant (1724 April 1724 - 12 February 1804). Despite never being married. Kant appears to have led a fulfilling social life. Before writing his main philosophical writings, he worked as a teacher and a mildly successful novelist. He had an extremely disciplined and strict life. He is well recognized for his contributions to metaphysical and ethical philosophy. The False Subtlety of the Four Syllogistic Figures, published in the 1760s, marked the start of Kant's mature work. He was appointed Professor of Logic and Metaphysics at Königsberg University in 1770 at the age of 45. In 1765, he wrote The Sensible and Intelligible World as his first dissertation. In 1781, Kant's Critique of Pure Reason got published. Kant's health was poor for a long time and deteriorated. He died in Königsberg on February 12, 1804, saying "Es ist gut"(it is good) just before he died. Kant was first buried within the cathedral, but in 1880 his remains were transferred to a neo-Gothic chapel that stood next to the cathedral's northeast corner. The chapel was demolished when it deteriorated over time to create room for the tomb, which was built on the same location."