[Footnote 6: _Treatise of Human Nature_ (Morals), iii. i.] [Footnote 7: Kant, _Prolegomena_ to Metaph. Introduction and _Crit. of Practical Reason_ (on the Claim of Pure Reason, _Werke,_ viii. 167).] CHAPTER IX. THE ATTEMPT AT A CRITICAL SOLUTION: KANT. The _Criticism of Pure Reason_ has been described by its author as a generalisation of Hume's problem. Hume, he thought, had treated his question on the 'relations of ideas' in their bearing upon 'matters of fact' mainly with reference to the isolated case of cause and effect. Kant extended the inquiry so as to comprise all those connective and unifying ideas which form the subject-matter of metaphysics. In his own technical language--which has lost its meaning for the present day--he asked, 'Are Synthetic judgments _a priori_ possible?'--a question which in another place he has translated into the form, 'Is the metaphysical faith of men sound, and is a metaphysical science possible?' By a metaphysics he meant in the first instance the belief in a more than empirical reality, and secondly the science which should give real knowledge of God, Freedom and Immortality,--a science whose objects would be God, the World, and the Soul. From a comparatively early date (1762-4) Kant had been inclined to suspect and distrust the claims of metaphysics to replace faith, and to give knowledge of spiritual reality; and he had tried to vindicate for the moral and religious life an independence of the conclusions and methods of the metaphysical theology and psychology of the day. But it was not till some years later--in 1770--that he formulated any very definite views as to the essential conditions of scientific knowledge: and it was not till 1781 that his theory on the subject was put together in a provisionally complete shape.