to another thing, which itself does not possess the quality, if you try to take it by itself. And, further, the objection from dream and delusion holds again. That objection urges that error points to a necessary relation of the object to our knowledge, even where error is not admitted. But such a relation would reduce every quality to appearance. We might, indeed, attempt once more here to hold the former line of defence. We might reply that the extended thing is a fact real by itself, and that only its relation to our percipience is variable. But the inevitable conclusion is not so to be averted. If a thing is known to have a quality only under a certain condition, there is no process of reasoning from this which will justify the conclusion that the thing, if unconditioned, is yet the same. This seems quite certain; and, to go further, if we have no other source of information, if the quality in question is non-existent for us except in one relation, then for us to assert its reality away from that relation is more than unwarranted. It is, to speak plainly, an attempt in the end without meaning. And it would seem that, if materialism is to stand, it must somehow get to the existence of primary qualities in a way which avoids their relation to an organ. But since, as we shall hereafter see (Chapter iv.), their very essence is relative, even this refuge is closed.
(d) But there is a more obvious argument against the sole reality of spatial qualities; and, if I were writing for the people an attack upon materialism, I should rest great weight on this point. Without secondary quality extension is not conceivable, and no one can bring it, as existing, before his mind if he keeps it quite pure. In short, it is the violent abstraction of one aspect from the rest, and the mere confinement of our attention to a single side of things, a fiction which, forgetting itself, takes a ghost for solid reality. And I will say a few words on this obvious answer to materialism.
