ABSTRACT
ALL our previous considerations have been based upon empirical facts. The laws of reflex movement, the muscular sensibility, the local differences in sensations of light and touch, the exhaustion consequent upon long exposure to sense-stimulus,—all these are phenomena which may be verified in experience. But at the conclusion of these considerations we seem to have left the firm ground of experience far behind us. We have ventured upon a psychological construction of space, from the associative co-operation of the specified factors. Is that not more than experience can ever achieve? Is not space a connate possession of the mind? Or, if not that, is it not at least an entirely new element in our knowledge, which is sui generis, and therefore not a derivative from anything else?
