"Take, for example, the mole, that unwearied worker. To dig with all its might with its enormous shovel claws is the occupation of its whole life; constant night surrounds it; its embryo eyes only make it avoid the light. It alone is truly an animal nocturnum; not cats, owls, and bats, who see by night. But what, now, does it attain by this life, full of trouble and devoid of pleasure? Food and the begetting of its kind; thus only the means of carrying on and beginning anew the same doleful course in new individuals. In such examples it becomes clear that there is no proportion between the cares and troubles of life and the results or gain of it. The consciousness of the world of perception gives a certain appearance of objective worth of existence to the life of those animals which can see, although in their case this consciousness is entirely subjective and limited to the influence of motives upon them. But the blind mole, with its perfect organisation and ceaseless activity, limited to the alternation of insect larvæ and hunger, makes the disproportion of the means to the end apparent. In this respect the consideration of the animal world left to itself in lands uninhabited by men is also specially instructive."