Note z — Chapter III

Neither can it be too often repeated that practical truth involves an enormous amount of speculative difficulty, and is received as the daily basis of human action in the face of doubts, which speculatively considered are absolutely insoluble. There is (as will appear in Chapter IV.) reason to extend this remark beyond what is commonly called practical truth far into the realm of speculative knowledge, or to speak more exactly, of all knowledge whatsoever. Suppose, for instance, the continuity of our inward power of receiving sense-impressions, of knowing, and reasoning; (our personal Identity) is a groundless belief;—Suppose too that our sense-impressions are reflections from self-created shadows and not from objective realities;—where can any knowledge be truly subsistent save in that place of exile now generally termed "the Unknowable"? Compare Additional Notes A and B appended to this present Chapter.