Ix Appe^idix. 



writer of the preliminary treatise, applies the term Science to all the bmnches 

 of knowledge that now receive this appellation, so far as they were then 

 developed, and to none others. The phraseology, in this respect, of subsequent 

 wi'iters has been almost uniform. The older sciences have retained the 

 appellation ; and new accessions of knowledge have received it, accordingly as 

 they have become assimilated in character to those which had been previously 

 formulated. 



By all authorities whatsoever the Pure Mathematics are denominated 

 sciences. In the case of Logic, and some other portions of mental philosophy, 

 a similar uniformity of usage has been exhibited throughout, with one signal 

 exception, that of Comte. In his classification of the sciences, that eminent, 

 but fanciful, thinker omits what is called Mental Science. This omission, 

 however, has been subsequently disapproved of by all authorities alike, 

 whether friends or foes of Positivism, whether disciples or dissentients. The 

 exclusion of Logic from the reputed domain of Science would not affect the 

 definition of Science which I propose j but it is worth while to notice, in 

 passing, that such an exclusion is alike unsupported by the weight of 

 authority, and would be in itself unreasonable. Whatever the human mind 

 may be, whether merely nerve and blood, or comprising elements transcending 

 our cognizance ; whether an act of thought is simply a scintillating snapping 

 of cerebration, or something else in addition to cerebral expenditure, and of 

 a nature yet more recondite j at all events, thought is a positive fact j the 

 results of thought take their place, and not the least important place, among 

 the phenomena of the universe j and the analysis and classification of thoughts 

 are manifestly not to be obtained from the appliances of Mechanics and 

 Chemistry. Thought is impalpable and imponderable ; but so ai'e several of 

 the powerful agents of nature, whose effects are analyzed, measured, and 

 gauged by methods which the positive philosophy does not fail to recognize. 

 Thought is invisible j but so are heat, air, and other agents ; nay, we do not, 

 strictly speaking, see even the light itself, but only the bodies from which it 

 emanates or is reflected. A moonless sl\y is traversed by the rays of the Sun, 

 although we cannot perceive them. We may, in fact, so far as the scientific 

 position of Logic and Psychology are concerned, adopt the dictum of that 

 great authority, Mr. Punch, who has uttered the following deliverance : — 



" What is Matter ? Never mind. 

 ^Vhat is Mind ? No matter." 



This may be interpreted as a facetious way of putting a common-sense truth, 

 that however inscrutable the nature in itself of matter or of mind may be, 

 still the operations of both the one and the other are cognizable in their 

 effects, and the two classes of phenomena thus designated are, as to our 

 perceptions, distinct. The actions of the mind are a portion of the phenomena 



