To this the following reply may be made. (_a_) The term _a priori_ applied to an apprehension should mean, not that it arises prior to experience, but that its validity is independent of experience. (_b_) That to which the term _a priori_ should be applied is not the apprehension of empty space, which is individual, but the apprehension of the nature of space in general, which is universal. (_c_) We do not apprehend empty space before we apprehend individual spatial relations of individual bodies or, indeed, at any time. (_d_) Though we come to apprehend _a priori_ the nature of space in general, the apprehension is not prior but posterior in time to the apprehension of individual spatial relations. (_e_) It does not follow from the temporal priority of our apprehension of individual spatial relations that our apprehension of the nature of space in general is 'borrowed from experience', and is therefore not _a priori_. 2. "We can never represent to ourselves that there is no space, though we can quite well think that no objects are found in it. It must, therefore, be considered as the condition of the possibility of phenomena, and not as a determination dependent upon them, and it is an _a priori_ representation, which necessarily underlies external phenomena."[17] [17] B. 38, M. 24. Here the premise is simply false. If 'represent' or 'think' means 'believe', we can no more represent or think that there are no objects in space than that there is no space. If, on the other hand, 'represent' or 'think' means 'make a mental picture of', the assertion is equally false. Kant is thinking of empty space as a kind of receptacle for objects, and the _a priori_ character of our apprehension of space lies, as before, in the supposed fact that in order to apprehend objects in space we must begin with the apprehension of empty space. The examination of Kant's arguments for the _perceptive_ character of our apprehension of space is a more complicated matter. By way of preliminary it should be noticed that they presuppose the possibility in general of distinguishing features of objects which belong to the perception of them from others which belong to the conception of them. In particular, Kant holds that our apprehension of a body as a substance, as exercising force and as divisible, is due to our understanding as conceiving it, while our apprehension of it as extended and as having a shape is due to our sensibility as perceiving it.[18] The distinction, however, will be found untenable in principle; and if this be granted, Kant's attempt to distinguish in this way the extension and shape of an object from its other features can be ruled out on general grounds. In any case, it must be conceded that the arguments fail by which he seeks to show that space in particular belongs to perception.