The serious attitude involves starting from the world and attributing more reality to the world than to oneself; at the very least the serious man confers reality on himself to the degree to which he belongs to the world. It is not by chance that materialism is serious; it is not by chance that it is found at all times and places as the favorite doctrine of the revolutionary. This is because revolutionaries are serious. They come to know themselves first in terms of the world which oppresses them, and they wish to change this world. In this one respect they are in agreement with their ancient adversaries, the possessors, who also come to know themselves and appreciate themselves in terms of their position in the world. Thus all serious thought is thickened by the world; it coagulates; it is a dismissal of human reality in favor of the world. The serious man is "of the world" and has no resource in himself. He does not even imagine any longer the possibility of getting out of the world, for he has given to himself the type of existence of the rock, the consistency, the inertia, the opacity of being-in-the-midst-of-the-world.