Kant relates the following anecdote: “A dove, which found great pleasure in spreading its wings, was troubled because this pleasure was of short duration; the simple bird was ignorant of the fact that its structure did not admit of its taking flights such as the swallow enjoys; not divining the real cause of its inability, it blamed the fluid ether whose resisting power it had felt, and thought how much better it would fly ‘in vacuo.’” The dove was mistaken. Kant’s crowning merit is having discovered the object of metaphysics not only in the categories of the understanding, without which, as Noiré says, no impression on the human mind would be possible, or even conceivable, but chiefly in the power, inherent in our nature, of resisting or yielding to impressions. It is this power, according to Kant, which constitutes the transcendental side of our knowledge. The empirical school of philosophers is tried by Kant’s recognition of the transcendental principle in man. Its members accuse the spiritualists of seeking to raise human nature beyond its proper level, and of wishing at the same time to open an inlet for other truths which claim a mysterious character and a superhuman authority. But Kant is the very last person to encourage the thought; on the contrary, through the whole of his philosophy he insists that these _à priori_ forms, or antecedent conditions of knowledge, have no authority whatever “except in and for experience,” and to use the category of causality, for instance, in order to establish the existence of God is, according to Kant, a philosophical blunder. “If only we could always remember the first intentions of our words, many philosophical difficulties would vanish.” In Greek οἰδα meant originally, I have seen, and therefore I know. In a court of justice the witness who says, “I saw” can hardly say anything more convincing. To apply such a word to our knowledge of causes, forces, and faculties would be a solecism--to apply it to God would be self-contradictory. Each of the abstract definitions of metaphysics given by Alfred Fouillée, Noiré, and Schopenhauer contains the leading conception of the subject; if presented in more simple language it would be within the comprehension of all; our understanding is blind to all with which it is not made acquainted by intuition derived from experience. Those things for which we have a strong desire, of which we have a certain conviction, but which are outside the sphere of our actual life, “for these,” as Max Müller says in this connection, “we want another word which should mean--I have not seen and yet I know, and that is--faith.”[64] Our senses may not always authorise us to affirm their reality. God and the future life are not made the subjects of phenomena.