Thus objects lack the fixedness of relations which events possess, and thus time and space could never be a direct expression of their essential relations. Two objects have (by the mediation of events) all the mutual space relations which they do have throughout their existence, and might have many which they do not have. Thus two objects, being what they are, have no necessary temporal and spatial relations which are essential to their individualities. 15.5 The chief confusion between objects and events is conveyed in the prejudice that an object can only be in one place at a time. That is a fundamental property of events; and whenever that property appears axiomatic as holding of some physical entity, that entity is an event. It must be remembered however that ordinary thought wavers confusedly between events and objects. It is the misplacement of this axiom from events to objects which has wrecked the theory of natural objects. 15.6 It is an error to ascribe parts to objects, where 'part' here means spatial or temporal part. The erroneousness of such ascription immediately follows from the premiss that primarily an object is not in space or in time. The absence of temporal parts of objects is a commonplace of thought. No one thinks that part of a stone is at one time and another part of the stone is at another time. The same stone is at both times, in the sense in which the stone is existing at those times (if it be existing). But spatial parts are in a different category, and it is natural to think of various parts of a stone, simultaneously existing. Such a conception confuses the stone as an object with the event which exhibits the actual relations of the stone within nature. It is indeed very natural to ascribe spatial parts to a stone, for the reason that a stone is an instance of a perceptual object. These objects are the objects of common life, and it is very difficult precisely to discern such an object in the events with which it has its most obvious relations. The struggle to make precise the concept of these objects either forces us back to the sense-objects or forward to the scientific objects. The difficulty is chiefly one of making thought clear. That there is a perception of an object with self-identity, is shown by the common usage of mankind. Indeed these perceptual objects forced upon mankind—and seemingly also on animals, unless it be those of the lowest type—their knowledge of the objectified character of nature. But the confusion of the object, which is a unity, with the events, which have parts, is always imminent. In biological organisms the character of the organism as an object is more clear.