REASONING. 331 



First, sagacity,* or the ability to discover what part, M, 

 lies embedded in the whole S which is before him ; 



Second, learning, or the ability to recall promptly M's 

 consequences, concomitants, or implications. f 



If we glance at the ordinary syllogism — 



M is P ; 



S is M; 



. • . S is P 



* J. Locke. Essay cone. Hum. Understanding, bk. iv. chap. ii. § 3. 



f To be sagacious is to be a good observer. J. S. Mill has a passage 

 which is so much in the spirit of the text that 1 cannot forbear to quote it. 

 "The observer is not he who merely sees the thing which is before his 

 eyes, but he who sees what parts that thing is composed of. To do this 

 well is a rare talent. One person, from inattention, or attending only ia 

 the wrong place, overlooks half of what he sees ; another sets down much 

 more than he sees, confounding it with what he imagines, or with what 

 he infers ; another takes note of the kiiid of all the circumstances, but 

 being inexpert in estimating their degree, leaves the quantity of each 

 vague and uncertain ; another sees indeed the whole, but makes such 

 an awkward division of it into parts, throwing things into one mass 

 which require to be separated, and separating others which might more 

 conveniently be considered as one, that the result is much the same, 

 sometimes even worse, than if no analysis had been attempted at all. It 

 would be possible to point out what qualities of mind, and modes of 

 mental culture, fit a person for being a good observer : that, however, is 

 a question not of Logic, but of the Theory of Education, in the most en- 

 larged sense of the term. There is not properly an Art of Observing. 

 There may be rules for observing. But these, like rules for inventing, are 

 properly instructions for the preparation of one's own mind ; for putting 

 it into the state in which it will be most fitted to observe, or most likely to 

 invent. They are, therefore, essentially rules of self-education, which is 

 a different thing from Logic. They do not teach how to do the thing, 

 but how to make ourselves capable of doing it. They are an art of 

 strengthening the limbs, not an art of using them. The extent and minute- 

 ness of observation which may be requisite, and the degree of decomposi- 

 tion to which it may be necessary to carry the mental analysis, depend on 

 the particular purpose in view. To ascertain the state of the whole uni- 

 verse at any particular moment is impossible, but would also be useless. 

 In making chemical experiments, we do not think it necessary to note the 

 position of the planets ; because experience has shown, as a very superficial 

 experience is sutficient to show, that in such cases that circumstance is not 

 material to the result : and accordingly, in the ages when man believed in 

 the occult influences of the heavenly bodies, it might have been unphilo- 

 sophical to omit ascertaining the precise condition of those bodies at the 

 moment of the experiment." (Logic, bk. iii. chap. vii. § 1. Cf. also bk. 

 IV. chap. II.) 



