Our cognition is concerned with questions which arise for us through the fact that a sphere of percepts, conditioned by place, time, and our subjective organization, is confronted by a sphere of concepts pointing to the totality of the universe. My task consists in reconciling these two spheres, with both of which I am well acquainted. Here one cannot speak of a limit to cognition. It may be that, at any particular moment, this or that remains unexplained because, through our place in life, we are prevented from perceiving the things involved. What is not found today, however, may be found tomorrow. The limits due to these causes are only transitory, and can be overcome by the progress of perception and thinking.