ETHOLOGY. 603 



ways its effect. These propositions, being assertive only of tendencies, are 

 not the less universally true because the tendencies may be frustrated. 



§ 5. While, on the one hand, Psychology is altogether, or principally, a 

 si;ionce of observation and experiment. Ethology, as I have conceived it, is, 

 as I have already remarked, altogether deductive. The one ascertains the 

 simple laws of Mind in general, the other traces their operation in complex 

 combinations of circumstances. Ethology stands to Psychology in a rela- 

 tion very similar to that in which the various branches of natural philoso- 

 phy stand to mechanics. The principles of Ethology are properly the mid- 

 dle principles, the axiotnata media (as Bacon would have said) of the sci- 

 ence of mind : as distinguished, on the one hand, from the empirical laws 

 resulting from simple observation, and, on the other, from the highest gen- 

 eralizations. 



And this seems a suitable place for a logical remark, which, though of 

 general application, is of peculiar importance in reference to the present 

 subject. Bacon has judiciously observed that the axiomata media of ev- 

 ery science principally constitute its value. The lowest generalizations, un- 

 til 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- 

 stances, 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 tlie 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 arrived at ; though there is no one propo- 

 sition laid down in his works for which he has been more extravagantly 

 eulogized. He enunciates as a universal rule that induction should pro- 

 ceed from the lowest to the middle principles, and from those to the high- 

 est, never reversing that ordei*, 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 instance of a deductive science, such as mechanics, 

 astronomy, optics, acoustics, etc., now are. In those sciences it is evident 

 that the higher and middle principles are by no means derived from the 

 lowest, but the reverse. In some of them the very highest generalizations 

 were those earliest ascertained with any scientific exactness ; as, for exam- 

 ple (in mechanics), the laws of motion. Those general laws had not, in- 

 deed, at first tlie acknoAvledged universality which they acquired after having 

 been successfully employed to explain many classes of phenomena to which 

 they were not originally seen to be applicable ; 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 

 were afterward recognized as the most general truths of the science were, 

 of all its accurate generalizations, those earliest arrived at. Bacon's great- 

 est merit can not therefore consist, as we are so often told that it did, in ex- 

 ploding the vicious method pursued by the ancients of flying to the high- 

 est generalizations first, and deducing the middle principles from them ; 

 since this is neither a vicious nor an exploded, but the universally accredited 

 method of modern science, and that to which it owes its greatest triumphs. 

 The error of ancient speculation did not consist in making the largest gen- 



