Immanuel Kant was born in Konigsberg, East Prussia, April 22, 1724, the son of a saddler of Scottish descent. The family was pietist, and the future philosopher entered the university of his native city in 1740, with a view to studying theology. He developed, however, a many-sided interest in learning, and his earlier publications were in the field of speculative physics. After the close of his period of study at the university he became a private tutor; then In 1755, privat-docent; and in 1770, professor. During the first eleven years of his professorship Kant published little, spending his energies in the meditation that was to result in the philosophical system of which the first part was given to the world in his "Critique of Pure Reason" in 1781. From that time till near the end of the century he issued volume after volume; yet when he died In 1804 he regarded his statement of his system as fragmentary.

Of the enormous importance of Kant in the history of philosophy, no idea can be given here. The important document which follows was published in 1785, and forms the basis of the moral system on which he erected the whole structure of belief in God, Freedom, and Immortality. Kant is often difficult and obscure, and became more so as he grew older; but the present treatise can be followed, in its main lines, by any intelligent person who is interested enough in the fundamental problems of human life and conduct to give it serious and concentrated attention. To such a reader the subtle yet clear distinctions, and the lofty and rigorous principles of action, which it lays down, will prove an intellectual and moral tonic such as hardly any other modern writer affords.