January 21, 1887 ] 



SGIEJ^CE. 



67 



By the processes I have described above, the 

 child reaches a large number of general or uni- 

 versal judgments. To these are added all the 

 general statements made to him by others in the 

 course of instruction. These he can now apply to 

 the explanation of particular or less general cases, 

 as has been already shown ; that is, he can 

 make use of deduction. The logical forms of this 

 kind of reasoning are: "All soldiers have to 

 fight ; John is a soldier, therefore John has to 

 fight;" or, "No mistakes deserve praise; this 

 is a mistake, therefore this does not deserve 

 praise." But though this is the logical, it is 

 seldom if ever the psychological order of in- 

 ference. As Mr. Sully points out, " in some 

 cases the conclusion first presents itself to the 

 mind, and the other judgments rise into distinct 

 consciousness later ; and in other cases the mind 

 does not at any stage distinctly represent more 

 than one of the two truths making up the prem- 

 ises." Again : besides starting with a general 

 truth and seeking to make applications of it, we 

 may also start with some particular statement or 

 fact, and then seek among the general truths al- 

 ready acquired for that under which it may be 

 brought. In our language work we may have an 

 instance of a noun in the genitive, and we seek to 

 find what rule for the genitive will explain our 

 instance. Or in our geometry work we may have 

 a theorem given us to prove: we assume it to be 

 true, and then seek to attach it to some known 

 and already proved theorem, and then, finally, 

 reverse our work to produce the proof required. 

 This last is the usual way in which children ex- 

 pl.ain things to themselves and others. " Why 

 am I blamed for having done this ? Because what 

 I did was called, or was, cruel, and acts called 

 cruel deserve blame," is the clear statement of the 

 reasoning which, more or less confusedly, will 

 pass through the mind of a child. In connection 

 with this, we should note the method by which 

 all our greatest discoveries concerning the laws of 

 nature have been made. The examination of a 

 certain number of particular cases suggests a 

 general principle (or more than one) under which 

 they may be brought. We assume the general 

 principle to be true, and deduce the results for 

 several particular instances. We then compare 

 these results with the results of actual observation 

 in the same cases. If the latter confirm the 

 former, we accept the general principle as true — 

 at any rate, for the time being ; if they do not, we 

 either modify our assumption or try another. It 

 was in this way that Newton and Faraday, and 

 numberless others, worked, and that all men of 

 science are now working. It was in this way 

 that the great theory of the conservation of energy 



was discovered, and which was verified so ad- 

 mirably by Mr. Joule's experiments. In this, as 

 in nearly all our complex reasoning, you will ob- 

 serve that induction and deduction are mixed ; 

 the former suggesting general truths, and the 

 latter deriving conclusions from them. Both 

 these two kinds of reasoning are liable, of course, 

 to error. Both depend on observation, reproduc- 

 tion, imagination ; both are processes based on 

 the detection of similarity. If these are faulty, 

 our conclusions will be fallacies. Especially in 

 the case of deduction is a mistaken idea of simi- 

 larity, or the want of discrimination, a fruitful 

 source of error ; the ambiguity, or want of clear- 

 ness, in the terms employed being also most fre- 

 quently a great cause of our going astray. 

 Attention as regards all that is employed in our 

 argument, and concentration as regards the 

 special object of our search, will also be necessary 

 parts of our outfit. 



As Mr. Sully has pointed out, the powers of 

 judging and reasoning show themselves later than 

 the power of conception. At quite an early age, 

 children will form rudimentary notions of things, 

 and will even go as far as the formation of im- 

 plicit judgments ; but they will not yet be able to 

 form explicit judgments. The order of develop- 

 ment appears to be as follows : I''. Implicit judg- 

 ments, — the results of observation and memory, 

 involving no inference ; 3*. Explicit judgments, 

 involving inference, about individual things, con- 

 sisting of statements about actual facts then 

 present ; 3°. Judgments concerning striking at- 

 tributes, later with reasons ; 4°. Judgments in- 

 volving consciousness of alternatives, introdu- 

 cing ' no ' and ' not : ' 5°. Judgments concerning 

 classes, the predicates becoming gradually more 

 general and more abstract; 6°. The curbing of 

 exaggerations and mis-statements, — less tendency 

 to treat fancies as realities, — criticism of the 

 statements of others, or increase of independence. 

 The development of reasoning follows very simi- 

 lar stages : 1". Reasoning from particulars to 

 particulars ; 2°. Then seeking for causes, with the 

 familiar ' why ; ' 8°. Deductive reasoning, consist- 

 ing of the application of simple rules to simple 

 particular cases, then to cases requiring a more 

 intimate understanding of the rule, then the ap- 

 plication of rules less simple ; 4°. Somewhat later 

 will come inductive reasoning, with ever-increas- 

 ing power of abstraction ; 5°. Lastly, complex 

 reasoning and chains of demonstration. 



For convenience, let me recapitulate the points 

 on which clear judgment and clear reasoning de- 

 pend. Clear judgments depend on clear concep- 

 tions and representations, and on the clear under- 

 standing of the connection stated and the terms 



