"The Conditioned is the mean between two extremes,--two inconditionates, exclusive of each other, _neither of which can be conceived as possible_,[K] but of which, on the principles of contradiction and excluded middle, _one must be admitted as necessary_. On this opinion, therefore, our faculties are shown to be weak, but not deceitful. The mind is not represented as conceiving two propositions, subversive of each other, as equally possible; but only as unable to understand as possible either of the two extremes; one of which, however, on the ground of their mutual repugnance, it is compelled to recognise as true. We are thus taught the salutary lesson, that the capacity of thought is not to be constituted into the measure of existence; and are warned from recognising the domain of our knowledge as necessarily co-extensive with the horizon of our faith. And by a wonderful revelation, we are thus, in the very consciousness of our inability to conceive aught above the relative and finite, inspired with a belief in the existence of something unconditioned beyond the sphere of all comprehensible reality."--_Discussions_, p. 15. [K] It must be remembered that, to conceive a thing as possible, we must conceive the manner in which it is possible, but that we may believe in the fact without being able to conceive the manner. Had Hamilton distinctly expressed this, he might have avoided some very groundless criticisms, with which he has been assailed for maintaining a distinction between the provinces of conception and belief. Against Materialism, and virtually against Positivism in general, he says:--