‘We must become as little children again, if we will be philosophers!’ The phrase appears here almost in passing, and Reid never came back to it again. And yet in it is contained the Open Sesame which gives access to the hidden spirit-treasures of the world. In this unawareness of Reid’s of the importance of what he thus had found we must see the reason for his incapacity to develop his philosophy beyond its first beginnings. This handicap arose from the fact that in all his thinking he was guided by a picture of the being of man which – as a child of his time, dominated by the contemporary religious outlook – he could never realize distinctly. Yet without a clear conception of this picture no justice can be done to Reid’s concept of common sense. Our next task, therefore, must be to evoke this picture as clearly as we can