In 1792 Kant, in the full height of his reputation, was involved in a collision with the Government on the question of his religious doctrines. Naturally his philosophy had excited the declared op position of all adherents of historical Christianity, since its plain tendency was towards a moral rationalism, and it could not be reconciled to the literal doctrines of the Lutheran Church. After the first part of his book, Die Religion innerhalb der Grenzen der blossen V ernunft, had appeared in the Berlin Journal, the publica tion of the remainder, which treats in a more rationalizing style of Christianity, was forbidden. Kant, thus shut out from Berlin, availed himself of his local privilege, and, with the sanction of the theological faculty of his own university, published the full work in KOnigsberg (1793). The Government, probably influenced as much by hatred and fear of the French Revolution, of which Kant was supposed to be a partisan, as by love of orthodoxy, resented the act ; and a secret cabinet order was received by him intimating the displeasure of the king, Frederick William II., and exacting a pledge not to lecture or write at all on religious subjects in future. With this mandate Kant, after a struggle, complied, and kept his engagement till 1797, when the death of the king, accord ing to his construction of his promise, set him free. The incident depressed his spirits. He withdrew in i794 frrom society; next year he gave up all his classes but one public lecture on logic or meta, physics ; and in 1797, before the removal of the interdict on his theological teaching, he ceased his public lectures, after an aca demic course of 42 years. In that year he had finished his treatises Die Metaphysik der Ethik, which, with his Anthropologie, com pleted in 1798, were the last considerable works that he revised with his own hand. His lectures on logic, on physical geography, on paedagogics, were edited during his lifetime by his friends and pupils. By way of asserting his right to resume theological dis quisition, he also issued in 1798 his Streit der Fakultaten, in which all the strongest points of his work on religion were urged afresh.
From the date of his retirement from the chair Kant declined in strength, and gave tokens of intellectual decay. His memory began to fail, and a large work at which he wrought night and day, on the connection between physics and metaphysics, was found to be only a repetition of his already published doctrines. After 1802, finding himself attacked with a weakness in the limbs at tended with frequent fits of falling, he mitigated the Spartan severity of his life, and consented to receive medical advice. A constant restlessness oppressed him; his sight gave way; his con versation became an extraordinary mixture of metaphors ; and it was only at intervals that gleams of his former power broke out, especially when some old chord of association was struck in natural science or physical geography. A few days before his decease, with a great effort he thanked his medical attendant for his visits in the words, "I have not yet lost my feeling for human ity." On Feb. 12, 1804, he died, having almost completed his Both year. His stature was small, and his appearance feeble. He was little more than five feet high ; his breast was almost concave, and, like Schleiermacher, he was deformed in the right shoulder. His senses were quick and delicate, and, though of weak constitution, he escaped by strict regimen all serious illness.
His life was arranged with mechanical regularity; and, as he never married, he kept the habits of his studious youth to old age.
His man-servant, who awoke him summer and winter at five o'clock, testified that he had not once failed in 3o years to respond to the call. After rising he studied for two hours, then lectured two hours, and spent the rest of the forenoon, till one, at his desk. He then dined at a restaurant, which he frequently changed, to avoid the influx of strangers, who crowded to see and hear him. This was his only regular meal; and he often prolonged the conversation till late in the afternoon. He then walked out for at least an hour in all weathers, and spent the evening in lighter read ing, except an hour or two devoted to the preparation of his next day's lectures, after which he retired between nine and ten to rest. In his earlier years he often spent his evenings in general society, where his knowledge and conversational talents made him the life of every party. His social circle included J. G. Hamann, the friend of Herder and Jacobi, who was thus a mediator between Kant and these philosophical adversaries.
Kant cared comparatively little for the history of speculation, but his acquaintance with books of science, general history, travels and belles lettres was boundless. He was well versed in English literature, chiefly of the age of Queen Anne, and had read English philosophy from Locke to Hume, and the Scottish school. He was at home in Voltaire and Rousseau, but had little or no acquaintance with the French sensational philosophy. He was familiar with all German literature up to the date of his Kritik, but ceased to follow it in its great development by Goethe and Schiller. It was his habit to obtain books in sheets from his publishers Kanter and Nicol ovius ; and he read over for many years all the new works in their catalogue, in order to keep abreast of universal knowledge.
As a lecturer, Kant avoided altogether that rigid style in which his books were written. He sat behind a low desk, with a few jot tings on slips of paper, or textbooks marked on the margin, before him, and delivered an extemporaneous address, opening up the subject by partial glimpses, and with many anecdotes or familiar illustrations, till a complete idea of it was presented. His voice was extremely weak, but sometimes rose into eloquence, and always commanded perfect silence. Though kind to his stu dents, he refused to remit their fees, as this, he thought, would dis courage independence. It was another principle that his chief ex ertions should be bestowed on the intermediate class of talent, as the geniuses would help themselves, and the dunces were beyond remedy.
Simple, honourable, truthful, kind-hearted and high-minded as Kant was in all moral respects, he had little sentiment. He had no enthusiasm for the beauties of nature, and indeed never sailed out into the Baltic, or travelled more than 4o miles from Konigsberg. Music he disregarded, and all poetry that was more than senten tious prose. His ethics have been reproached with some justice as setting up too low an ideal for the female sex. Though a faithful friend, he could not bear to visit his friends in sickness, and after their death he repressed all allusion to their memory.
On Feb. 12, 1904, the moth anniversary of Kant's death, a Kantian society (Kantgesellschaft) was formed at Halle under the leadership of H. Vaihinger to promote Kantian studies; it supports the periodical Kantstudien (founded 1896).