Sentence:  One of the wisest of uninspired men has not hesitated to declare the dog a great mystery, on account of this dawning of a "moral" nature unaccompanied by any the least evidence of "reason", in whichever of the two senses we interpret the word—whether as the "practical" reason, that is, the power of proposing an "ultimate" end, the determinability of the Will by ideas; or as the <WSD>"sciential</WSD>" reason, that is, the faculty of concluding universal and necessary truths from particular and contingent appearances. 
Meaning of the word marked with <WSD> tags:  Of or pertaining to science or to knowledge.