Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/413

RhPROP. XXII.———— is thus possible under other conditions than the contingent laws to which certain intelligences may be subject: in other words, there is no contradiction in affirming that an intelligent being may have knowledge of some kind or other, without having such senses as we have. This being understood, the demonstration is as follows: Whatever conditions of knowledge may be conceived (without a contradiction) to be changed, leaving knowledge still possible, these, according to the definition, are contingent laws. But our five senses may be conceived (without a contradiction) to be changed, leaving knowledge (knowledge, of course, of a different character from that which we now possess) still possible. Therefore our senses are contingent conditions of cognition; they are not binding on intelligence necessarily and universally.

1. This proposition takes us into a region quite different from that in which we have been hitherto expatiating. It takes us into the region of contingent truth—of truth, in regard to cognition, which might conceivably have been other than it is. Till now we have been dealing with necessary truth—of truth absolutely unalterable—of law binding universally. The twenty-one preceding propositions give expression to the necessary truths of reason,—