There is no call to discuss here the system of Kant, or even to describe it in detail. The means of studying the system are within easy reach of English readers.[1] Our concern is to know the method which Kant employed, and the use he made of it, the ground he took and the positions he held, so far as this can be indicated within reasonable compass, and without becoming involved in the complexity of the author's metaphysics. The Critique of Pure Reason is precisely what the title imports--a searching analysis of the human mind; an attempt to get at the ultimate grounds of thought, to discover the à priori principles. "Reason is the faculty which furnishes the principles of cognition à priori. Therefore pure reason is that which contains the principles of knowing something, absolutely à priori. An organon of pure reason would be a summary of these principles, according to which all pure cognition à priori can be obtained, and really accomplished. The extended application of such an organon would furnish a system of pure reason." [1] See Kant's Critique of Pure Reason, London, 1838; Morell's History of Modern Philosophy; Chalybäus' Historical Development of Speculative Philosophy from Kant to Hegel; Lewes' Biographical History of Philosophy; Cousin's Leçons, OEuvres, Iere série, vol. 5, give a clear account of Kant's philosophy. The problem of modern philosophy may be thus stated: _Have we or have we not ideas that are true of necessity, and absolutely? Are there ideas that can fairly be pronounced independent in their origin of experience, and out of the reach of experience by their nature?_ One party contended that all knowledge was derived from experience; that there was nothing in the intellect that had not previously been in the senses: the opposite party maintained that a portion, at least, of knowledge came from the mind itself; that the intellect contained powers of its own, and impressed its forms upon the phenomena of sense. The extreme doctrine of the two schools was represented, on the one side by the materialists, on the other by the mystics. Between these two extremes various degrees of compromise were offered. The doctrine of innate ideas, ascribed to Descartes,--though he abandoned it as untenable in its crude form,--affirmed that certain cardinal ideas, such as causality, infinity, substance, eternity, were native to the mind, born in it as part of its organic constitution, wholly independent therefore of experience. Locke claimed for the mind merely a power of reflection by which it was able to modify and alter the material given by the senses, thus exploding the doctrine of innate ideas.