Book written by Vlady Stévanovich.
 Each living being has a knowledge of the world adapted to its means of action. Life has provided him with instruments of perception which allow him to create his own little world within a whole of which he can have no knowledge. The world of the microbe is not the same as that of the earthworm, fish or man. The biological justification for such a distribution of knowledge is obvious.
 Why has man been additionally endowed with a consciousness? It is this which means that he no longer identifies with the world that he also cuts out, in the whole. It is this which causes man to see the world as exterior. Like an object to know, to explore.