Should one object, finally, that, if a given line in consciousness be composed of a limited number of indivisible elements of sensation, consciousness ought to distinguish these single elements and testify as to their number; I answer that what is in consciousness is not necessarily in a clear analytical consciousness, nor well distinguished from other elements. For example, I am at present conscious of a stream of sensations which I connect with the hand that holds my pen. The single elements in this complex I cannot distinguish from each other, nor can I give their number. It does not follow that I am to assume the number to be infinite. Much less should I be impelled to make this assumption, if it necessitated my accepting as true what I see to be flatly contradictory, as in the case under discussion. It was because of this vagueness and lack of discrimination in the testimony of consciousness that I said, some distance back, that consciousness _seems_ to testify that any finite line in it is composed of simple parts. If the testimony were quite clear, the matter would be settled at once. As it is not quite clear, the matter has to be settled on a deductive basis. The most reasonable solution appears to be the Berkeleyan. So much for the line immediately perceived, the line in consciousness. What shall we say to one who is willing to admit that this line is not infinitely divisible, but is composed of simple sense-elements; and yet who maintains that there exists an "external" line corresponding to it, which is not immediately perceived, and is infinitely divisible? We may begin by suggesting to him that an "external" point moving over this "external" line must perform the wholly impossible feat to which Clifford condemns a point moving over a line; and we may farther suggest that, if the "external" world be an intelligible world at all, a contradiction may be as much out of place in it as anywhere else. And if the existence of this world be problematic, a thing not self-evident, it seems quite reasonable to demand very good proof indeed of the existence, of that which contains in its very conception such excellent reasons for believing in its non-existence. This proof, the student of the history of speculation will testify, has not as yet been forthcoming.