In attempting to explain the nature and origin of the whole system of human knowledge, Kant divides our intellectual being into _three_ distinct faculties,--sensation, understanding, and reason. He supposes that from sensation we derive the whole _matter_ of our knowledge; that from the understanding we derive its _form_, or the manner in which it is conceived of by us; and that from reason we derive certain general or abstract notions, which are highly useful, since they give a systematic unity to human thought, but which have no _objective validity_, that is, either no reality in nature that corresponds to them, or none, at least, that can be scientifically demonstrated. From this fundamental principle of his system it follows, that the only part of our knowledge which has any objective reality is that which is derived from our sense-perceptions, all else being purely _formal or subjective_, and arising solely from the laws of our own mental nature, which determine us to conceive of things in a particular way; and that even that part of our knowledge which is derived from sense-perception is purely phenomenal, since we know nothing of any object around us beyond the bare fact that it exists, and that it appears to us to be as our senses represent it. Hence the _skeptical_ tendency of Kant's speculations, in so far as the scientific certainty of our knowledge is concerned. The _practical utility_ of that knowledge is not disputed, but its _objective reality_, or the possibility of proving it, is, to a large extent, denied. Still he admits a primitive _dualism_, and a radical distinction between _the subject and the object_, between the mind which thinks and the matter of its thoughts. The _matter_ comes from without, the _form_ from within; and the senses are the channels through which the phenomena of nature are poured into the mould of the human mind. All knowledge implies this combination of _matter_ with _form_, and is possible only on the supposition of the concurrent action both of the _object_ and _subject_; not that either of the two is known to us in its essence, or that their real existence can be scientifically demonstrated, for we know the subject only in its relation to the object, and the object only in its relation to the subject; but that this _relation_ necessarily requires the joint action of both, by which alone we can acquire the only knowledge of which we are capable, and which is supposed to be purely phenomenal, relative, and subjective. It is true that we are capable of forming certain grand ideas, such as that of God, the universe, and the soul; but these are the pure products of Reason, the mere personifications of our own modes of thinking, and have no objective reality, at least none that can be scientifically demonstrated. But, while "the Speculative Reason" is held to be incompetent to prove the existence of God, "the Practical Reason" is appealed to; and in the conscious liberty of the soul, and its sense of