we agree in opinion as to the merits of the Common- Sense Philosophy. Considered in its details and accessories, it certainly contains many good things; but, viewed as a whole and in essentialibus, it is about the greatest humbug that ever was palmed off upon an unwary world. As an instance among many which might be adduced, of the ambiguity of the word, and of the vacillation of the members of this school, it may be remarked that while Reid made the essence of common-sense to consist in this, that its judgments are not conclusions obtained by ratiocination (Works, Sir W. Hamilton's edition, p. 425), Stewart, on the contrary, holds that these judgments are "the result of a train of reasoning so rapid as to escape notice" (Elements, vol. ii. p. 103). Sir W.'s one hundred and six witnesses are a most conglomerate set, and a little cross-examination would try their mettle severely.'
The most important part of Ferrier's system was his working out of the 'Theory of Ignorance,' in which, indeed, he might congratulate himself in having in great measure broken open new ground. He says of it: 'Hurrah, εὕρηκα, I have discovered the Law of Ignorance—and if I had a hecatomb of kain hens at my command I would sacrifice them instanter to the propitious patron of metaphysics. Look you here. The Law of Knowledge is this, that, in order to know any one thing we must always know two things; hoc cum alio—object plus subject—thing + me. This is the unit of knowledge. Analogously, only inversely, in order to be ignorant of any one thing we must be ignorant of two things—hujus cum alio—object plus subject—thing + me. This is the unit of ignorance.' Apparently, in spite of full explanation of his newly-discovered view,
