It is not surprising. Philosophers speak a language of their own, which must be learnt before it can be understood, which is the case with all languages.
Kant develops this thesis with greater simplicity and clearness. “As long as the human intellect moves in the sphere of the senses and of experience it is safe; this sphere is very vast; it is there that all phenomena may be known which appears in space and time, that is to say, all belonging to the phenomenal world in which we live. But if the intellect rebels against the gaoler which holds it captive in the magic circle, breaks its chains and enters into the region of ideals, it will err.”
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.
All that I have said as to what distinguishes knowledge acquired by the senses from that which is anterior to all experience (Kant was the first to make this distinction), might seem simple to those heedless minds which are surprised at nothing, but complicated and confused to minds however little attentive, and quite useless to the rest of us. There may be something of truth in each of these primitive and superficial estimations, but the whole truth is that all this is very scientific, so scientific as to require a Kant to enable those who reflect to give a lucid account of it.
It was by the help of this learned science that Kant broke the serried ranks of his antagonists. Confronted by two philosophical opinions, both of which he considered erroneous, he proved to the materialists Condillac, Hume, and Locke, that there is something within us which could never have been supplied from without, which therefore belongs to our ego, that is to say to the subject thinking and not to the object thought of, or matter; then turning against the Idealists of the time of Berkeley, he shows that there is something without us which could never have been supplied from within; and when he proved that intellect and matter are correlative, that they exist for each other, depend on each other, form together a whole that should never have been torn asunder, two streams of philosophic thought, which had been running in separate beds, met for the first time.
The existence of the phenomenal world being proved by the irrefragable testimony of the senses, is admitted also by reason, and, as a necessary consequence, another, not only in appearance, but which will be, assuredly; as sound is independent of our hearing, as material objects are independent of our sight; for though Kant declares our inability to know objects as they are in themselves, he does not deny their existence, since he says, “We should be capable, if not of knowing things as they are in themselves, at least of knowing them as they are to us, otherwise we should arrive at the irrational conclusion, that there may be appearances without something that appears.”