Probably it has already been remarked that this Unknowable has brought us around again to that amusing “telephone exchange” discussed in the third chapter.  But if the reader feels within himself the least weakness for the Unknowable, I beg him to consider carefully, before he pins his faith to it, the following:—­

(1) If we do perceive external bodies, our own bodies and others, then it is conceivable that we may have evidence from observation to the effect that other bodies affecting our bodies may give rise to sensations.  In this case we cannot say that we know nothing but sensations; we know real bodies as well as sensations, and we may refer the sensations to the real bodies.

(2) If we do not perceive that we have bodies, and that our bodies are acted upon by others, we have no evidence that what we call our sensations are due to messages which come from “external things” and are conducted along the nerves.  It is then, absurd to talk of such “external things” as though they existed, and to call them the reality to which sensations, as appearances, must be referred,

(3) In other words, if there is perceived to be a telephone exchange with its wires and subscribers, we may refer the messages received to the subscribers, and call this, if we choose, a reference of appearance to reality.

But if there is perceived no telephone exchange, and if it is concluded that any wires or subscribers of which it means anything to speak must be composed of what we have heretofore called “messages,” then it is palpably absurd to refer the “messages” as a whole to subscribers not supposed to be composed of “messages”; and it is a blunder to go on calling the things that we know “messages,” as though we had evidence that they came from, and must be referred to, something beyond themselves.

We must recognize that, with the general demolition of the exchange, we lose not only known subscribers, but the very notion of a subscriber.  It will not do to try to save from this wreck some “unknowable” subscriber, and still pin our faith to him.

(4) We have seen that the relation of appearance to reality is that of certain experiences to certain other experiences.  When we take the liberty of calling the Unknowable a reality, we blunder in our use of the word.  The Unknowable cannot be an experience either actual, possible, or conceived as possible, and it cannot possibly hold the relation to any of our experiences that a real thing of any kind holds to the appearances that stand as its signs.

(5) Finally, no man has ever made an assumption more perfectly useless and purposeless than the assumption of the Unknowable.  We have seen that the distinction between appearance and reality is a serviceable one, and it has been pointed out that it would be of no service whatever if it were not possible to refer particular appearances to their own appropriate realities.  The realities to which we actually refer appearances