568 



LOGIC OF THE MORAL SCIENCES. 



something will always or certainly 

 happen, but only that such and such 

 will be the effect of a given cause, 

 so fg-r as it operates uncounteracted. 

 It is a scientific proposition that 

 bodily strength tends to make men 

 courageous ; not that it always makes 

 them so : that an interest on one side 

 of a question tends to bias the judg- 

 ment ; not that it invariably does so : 

 that experience tends to give wisdom; 

 not that such is always its effect. 

 These propositions, being assertive 

 only of tendencies, are not the less 

 universally true because the tenden- 

 cies may be frustrated. 



§ 5. While, on the one hand. Psy- 

 chology is altogether, or principally, 

 a science of observation and experi- 

 ment, Ethology, as I have conceived 

 it, is, as I have already remarked, 

 altogether deductive. The one ascer- 

 tains the simple laws of Mind in 

 general, the other traces their opera- 

 tion in complex combinations of cir- 

 cumstances. Ethology stands to Psy- 

 chology in a relation very similar to 

 that in which the various branches of 

 natural philosophy stand to mechanics. 

 The principles of Ethology are properly 

 the middle principles, the axiomata 

 media (as Bacon would have said) of 

 the science of mind : as distinguished, 

 on the one hand, from the empirical 

 laws resulting from simple observa- 

 tion, and on the other from the highest 

 generalisations. 



And this seems a suitable place for 

 a logical remark, which, though of 

 general application, is of peculiar im- 

 portance in reference to the present 

 subject. Bacon has judiciously ob- 

 served that the axiomata media of 

 every science principally constitute 

 its value. The lowest generalisations, 

 until explained by and resolved into 

 the middle principles of which they 

 are the consequences, have only the 

 imperfect accuracy of empirical laws ; 

 while the most general laws are too 

 general, and include too few circum- 

 etances, to give sufficient indication 

 of what happens in individual cases 



where the circumstances are almost 

 always immensely numerous. In the 

 importance, therefore, which Bacon 

 assigns in every science to the middle 

 principles, it is impossible not to 

 agree with him. But I conceive him 

 to have been radically wrong in his 

 doctrine respecting the mode in which 

 these axiomata media should be ar- 

 rived at ; though there is no one pro- 

 position laid down in his works for 

 which he has been more extravagantly 

 eulogised. He enunciates as an uni- 

 versal rule that induction should pro- 

 ceed from the lowest to the middle 

 principles, and from those to the 

 highest, never reversing that order, 

 and consequently, leaving no room 

 for the discovery of new principles by 

 way of deduction at all. It is not 

 to be conceived that a man of his 

 sagacity could have fallen into this 

 mistake if there had existed in his 

 time, among the sciences which treat 

 of successive phenomena, one single in- 

 stance of a deductive science, such as 

 mechanics, astronomy, optics acous- 

 tics, &c., now are. In those sciences 

 it is evident that the higher and 

 middle principles are by no means 

 derived from the lowest, but the re- 

 verse. In some of them the very 

 highest generalisations were those 

 earliest ascertained with any scien- 

 tific exactness ; as, for example, (in 

 mechanics, ) the laws of motion . Those 

 general laws had not indeed at first 

 the acknowledged universality which 

 they acquired after having been suc- 

 cessfully employed to explain many 

 classes of phenomena to which they 

 were not originally seen to be appli- 

 cable ; as when the laws of motion 

 were employed, in conjunction with 

 other laws, to explain deductively the 

 celestial phenomena. Still the fact 

 remains that the propositions which j| 

 were afterwards recognised as the 

 most general truths of the science 

 were, of all its accurate generalisa- 

 tions, those earliest arrived at. Ba- 

 con's greatest merit cannot therefore 

 consist, as we are so often told that it 

 did, in exploding the vicious method 



