Fish

gregorovius thought that somewhere chestov had written about aquariums
with a removable glass partition which could be taken out any time
and that the fish, who was accustomed to his compartment, would
never try to go over to the other side. he would come to a point in the water,
turn around, and swim back, without discovering that the obstacle was gone,
that all he had to do was to keep on going forward...