In the attitude oriented toward essences we can, beginning with the factual, common world, investigate the essential form of a human surrounding world and investigate the essential form of a surrounding world which, in the alteration of surrounding worlds through penetration into alien human civilizations, is ever constituting itself anew; and, assuming the possibility that this process could go on infinitely, we can sketch out the structure of an existing world as world of possible experience,.e., as emerging through an ongoing process of correction throughout possible transitional surrounding worlds.