Such a system is worth precisely what the intuition is worth, precisely what the man who has the intuition is worth. For, in a great thinker, the hypothesis is the man. His hypothesis is the concentrated essence of his energy, his observation, his thought, his imaginative powers, and even of his passions. Nicolai's hypothesis is vigorous, and it takes risks. The central idea of his book may be summed up as follows: "There exists a genus humanum, and there is only one such genus. The human race, humanity as a whole, is but a single organism, and has a common consciousness." Whoever speaks of a living organism, speaks of transformation and of unceasing movement. This perpetuum mobile gives its peculiar colour to Nicolai's reflections. In general, we who are advocates or opponents of the war tend to pass judgment on it almost exclusively in abstracto. We conceive it as static and absolute. It may almost be said that as soon as a thinker concentrates upon a subject in order to study it, his first step is to kill it. To a great biologist all is movement, and movement is the material of his study. The social or moral question that concerns us is not whether war is good or bad in the sphere of the eternal; but whether war is good or bad for us in our own moment of time. Now, for Nicolai, war is a stage in human evolution which man has long outgrown. His book depicts for us this evolutionary flux of instincts and ideas, an irresistible current in which there is never a backwash. * * * * *