In the course of our investigations we shall discover the peculiarity in human nature which - during the first phase, now ended, of man's struggle towards scientific awareness - has caused this renunciation of all sense-experiences except those which come to man through the sight of a single colour-blind eye. It will then also become clear out of what historic necessity this self-restriction of scientific inquiry arose. The acknowledgment of this necessity, however, must not prevent us from recognizing the fact that, as a result of this restriction, modern scientific research, which has penetrated far into the dynamic substrata of nature, finds itself in the peculiar situation that it is not at all guided by its own concepts, but by the very forces it tries to detect. And in this fact lies the root of the danger which besets the present age.⁵