VII. Are There Limits to Knowledge?

It is from a Dualism such as this that there arises the distinction between the object of perception and the thing-in-itself, which Kant introduced into science, and which, to the present day, we have not succeeded in expelling. According to our interpretation, it is due to the nature of our spiritual organization that a particular thing can be given to us only as a percept. Thinking then overcomes this particularity by assigning to each percept its legitimate place in the world as a whole. As long as we determine the separated parts of the cosmos as percepts, we are simply following, in this sorting out, a law of our subjectivity. If, however, we regard all percepts, taken together, merely as one part, and contrast with this a second part, viz., the things-in-themselves, then our philosophy is building castles in the air. We are then engaged in mere playing with concepts. We construct an artificial opposition, but we can gain no content for the second of these opposites, for such a content for a particular thing can be gathered only from perception.