seen that privation and failure imply always an outlying field of reality; and such an outlying field is here unmeaning. To say “you might find it” sounds modest, but it assumes positively a sphere in which the thing might be found. And here the assumption contradicts itself, and with that contradiction the doubt bodily disappears.
The criterion of truth may be called inconceivability of the opposite, but it is essential to know what we mean by such inability. Is this absolute or relative, and to what extent is it due to privation and mere failure? We have in fact, once more here, to clear our ideas as to the meaning of impossibility (Chapters xxiv. and xxvi.). Now the impossible may either be absolute or relative, but it can never be directly based on our impotence. For a thing is impossible always because it contradicts positive knowledge. Where the knowledge is relative, that knowledge is certainly more or less conditioned by our impotence. And hence, through that impotence, the impossibility may be more or less weakened and made conditional. But it never is created by or rests upon simple failure. In the end one has to say “I must not,” not because I am unable, but because I am prevented.
The impossible absolutely is what contradicts the known nature of Reality. And the impossible, in this sense, is self-contradictory. It is indeed an attempt to deny which, in the very act, unwittingly affirms. Since here our positive knowledge is all-embracing, it can rest on nothing external. Outside this knowledge there is not so much as an empty space in which our impotence could fall. And every inability and failure already presupposes and belongs to our known world.
The impossible relatively is what contradicts any subordinate piece of knowledge. It cannot be, unless something which we hold for true is, as such, given up. The impossibility here will vary in degree,
