Note AC — PREFACE

The assumption that these two expressions are or ought to be synonymous is tacitly made by Mr. Mill at the opening of this chapter. He opens it with a passage from the Discussions, in which Hamilton says that the existence of things in themselves is only indirectly revealed to us “through certain qualities related to our faculties of knowledge;” and then proceeds to show that the author did not hold the doctrine which these phrases “seem to convey in the only substantial meaning capable of being attached to them;” namely, “that we know nothing of objects except their existence, and the impressions produced by them upon the human mind.” Having thus quietly assumed that “things in themselves” are identical with “objects,” and “relations” with “impressions on the human mind,” Mr. Mill bases his whole criticism on this tacit petitio principii. He is not aware that though Reid sometimes uses the term relative in this inaccurate sense, Hamilton expressly points out the inaccuracy and explains the proper sense.—(See Reid’s Works, pp. 313, 322.)