But humanity cannot have this aid, because it is always moving along a hitherto untrodden track, and has no one to ask how to understand life, and to act in the conditions on which it is entering and through which no one has ever passed before.

Nevertheless, just as a man with wife and children cannot continue to look at life as he looked at it when he was a child, so too in the face of the various changes that are taking place, the greater density of population, the establishment of communication between different peoples, the improvements of the methods of the struggle with nature, and the accumulation of knowledge, humanity cannot continue to look at life as of old, and it must frame a new theory of life, from which conduct may follow adapted to the new conditions on which it has entered and is entering.