contained. On it depends in the first place the intuitive perception of the external world; for the senses by themselves are only capable of impression, a thing which is very far from being intuitive perception; indeed, the former is nothing but the material of the latter: ???? ???, ?a? ???? ????e?, t'???a ???? ?a? t????.

(The mind sees, the mind hears; everything else is deaf and blind.) Intuitive perception is the result of our directly referring the impressions of the sense-organs to their cause, which, exactly because of this act of the intelligence, presents itself as an external object under the mode of intuition proper to us, i.e., in space. This is a proof that the Law of Causality is known to us a priori, and does not arise from experience, since experience itself, inasmuch as it presupposes intuitive