According to Bergson this difference in form is one of the two essential respects in which abstractions fail to represent facts and in which, consequently, we are led into error as to the facts if we fail to distinguish them from the abstractions in terms of which we explain them, or take for granted that they correspond exactly with our explanations. Bergson gives the name “space” to the form which belongs to abstractions but not to actual facts: abstractions, he says, are “spatial,” but facts are not. This use of the word “space” is peculiar and perhaps unfortunate. Even as it is ordinarily used the word “space” is ambiguous, it may mean either the pure space with which higher mathematics is concerned, or the public space which contains the common sense things and objects and their qualities which make up the every day world, or the private space of sensible perception. When Bergson speaks of “space,” however, he does not mean either pure or public or private space, he means an _a priori_ form imposed by intellectual activity upon its object. This resembles Kant’s use of the word, but Bergson’s “space” is not, like Kant’s, the _a priori_ form of sense acquaintance, but of thought, in other words logical form. For Bergson “spatial” means “logical,” and since so much misunderstanding seems to have been caused by his using the word “space” in this peculiar sense we shall perhaps do better in what follows to use the word “logical” instead. Now whatever is logical is characterised by consisting of distinct, mutually exclusive terms in external relations: all schemes, for instance, and diagrams, such as a series of dots one above the other, or one below the other, or one behind, or in front of the other, or a series of instants one after the other, or a series of numbers, or again any arrangements of things or qualities according to their relations, such as colours or sounds arranged according to their resemblance or difference; in all these each dot or instant or number or colour-shade or note, is quite distinct from all the others, and the relations which join it to the others and give it its position in the whole series are external to it in the sense that if you changed its position or included it in quite another series it would nevertheless still be just the same dot or instant or number or quality as before. These two logical characteristics of mutual distinction of terms and externality of relations certainly do belong to the abstractions employed in explanations, and we commonly suppose that they belong to everything else besides. Bergson, however, believes that these logical characteristics really only belong to abstractions and are not discovered in facts but are imposed upon them by our intellectual bias, in the sense that we take it for granted that the facts which we know directly must have the same form as the abstractions which serve to explain them.