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LOGIC OF THE MOBAL SCIENCES. 



CHAPTER XII. 



OF THE LOGIC OF PRACTICE, OR ART ; 

 INCLUDING MORALIXy AND POUOy. 



§ I. In the preceding chapters we 

 have endeavoured to characterise the 

 present state of those among the 

 branches of knowledge called Moral 

 which are sciences in the only proper 

 sense of the term, that is, inquiries 

 into the course of nature. It is custo- 

 mary, however, to include under the 

 term Moral Knowledge, and even 

 (though improperly) under that of 

 Moral Science, an inquiry the results 

 of which do not express themselves 

 in the indicative, but in the impera- 

 tive mood, or in periphrases equiva- 

 lent to it ; what is called the know- 

 ledge of duties, practical ethics, or 

 morality. 



Now, the imperative mood is the 

 characteristic of art, as distinguished 

 from science. Whatever speaks in 

 rules or precepts, not in assertions 

 respecting matters of fact, is art; and 

 ethics or morality is properly a por- 

 tion of the art corresponding to the 

 sciences of human nature and society.* 



The Method, therefore, of Ethics, 

 can be no other than that of Art, or 

 Practice, in general : and the portion 

 yet uncompleted, of the task which 

 we proposed to ourselves in the con- 

 cluding Book is to characterise the 

 general Method of Art, as distin- 

 guished from Science. 



§ 2. In all branches of practical 

 business, there are cases in which in- 

 dividuals are bound to conform their 

 practice to a pre-established rule, 

 while there are others in which it is 

 part of their task to find or construct 

 the rule by which they are to govern 

 their conduct. The first, for example, 

 is the case of a judge under a definite 



* It is almost superfluous to observe, that 

 there is another mt-aniiig of the word Art, 

 in which it may b* said to denote the poeti 

 cal depjirtment or aspect of things in gene- 

 ral, in contradistinction to the scientific. 

 In the text, the word is used in its older, 

 aud, I hope, not yet ob.solete sense. 



■\^Titten code. The judge is not called 

 upon to determine what course would 

 be intrinsically the most advisable in 

 the particular case in hand, but only 

 within what rule of law it falls ; what 

 the legislature has ordained to be done 

 in the kind of case, and must there- 

 fore be presumed to have intended 

 in the individual case. The method 

 must here be wholly and exclusively 

 one of ratiocination or syllogism ; and 

 the process is obviously what in our 

 analysis of the syllogism we showed 

 that all ratiocination is, namely, the 

 interpretation of a formula. 



In order that our illustration of the 

 opposite case may be taken from the 

 same class of subjects as the former, 

 we will suppose, in contrast with the 

 situation of the judge, the position 

 of the legislator. As the judge has 

 laws for his guidance, so the legis- 

 lator has rules and maxims of policy ; 

 but it would be a manifest error to 

 suppose that the legislator is bound 

 by these maxims in the same manner 

 as the judge is bound by the laws, 

 and that all he has to do is to argue 

 down from them to the particular 

 case, as the judge does from the laws. 

 The legislator is bound to take into 

 consideration the reasons or grounds 

 of the maxim ; the judge has nothing 

 to do with those of the law, except so 

 far as a consideration of them may 

 throw light upon the intention of the 

 lawmaker, where his words have left 

 it doubtful. To the jndge, the rule, 

 once positively ascertained, is final ; 

 but the legislator, or other practi- 

 tioner, who goes by rules rather than 

 by their reasons, like the old-fa- 

 shioned German tacticians who were 

 vanquished by Napoleon, or the phy- 

 sician who preferred that his patients 

 should die by rule rather than recover 

 contrary to it, is rightly judged to be 

 a mere pedant, and the slave of his 

 formulas. 



Now, the reasons of a maxim of 

 policy, or of any other rule of art, can 

 be no other than the theorems of the 

 corresponding science. 



The relation in which rules of art 



