THE LAW OF HABIT. 47 



science ; and there is profound truth in the saying of Prof. Huxley : 

 '* On whatever ground we term physiology science, psychology is 

 entitled to the same appellation ; and the method of investigation 

 which elucidates the true relations of the one set of phenomena will 

 discover those of the other." As facts given ns for study, psychical 

 facts are to be ti'eated under the same rules of observation and analy- 

 sis as those^of physics ; instances are to be brought in to estaV)lish con- 

 clusions, and must be ascertained by similar laws of evidence and with 

 equal precision. But it should never be forgotten that in the region 

 of mind, and when the laws and purposes of mental phenomena are 

 in question, we are working in a region tliat in many ways transcends 

 the physical, transcends it in the complexity of processes concerned, 

 in the obscurity of many of its conditions, and the difficulty of avail- 

 able means of inquiry ; and, at least in a certain stage of our advance- 

 ment to truth, omitting hei'e the question whether it must not always 

 be the case, a higher mode of explanation than the merely physical 

 is that which"'alone satisfies. It is only while psychical facts remain, 

 as it were, upon the dissecting table, or are subjected to reagents in 

 the laboi'atory, and only while thus they stand before us on the same 

 footing with the facts of physiology or of chemistry, and we have, or 

 may have, a thorough knowledge of the conditions affecting any par- 

 ticular experiment, that these facts are at all amenable to the methods 

 that for scientific purposes prove sufficient within the spheres of 

 sjjeculation referred to. When they rise into the realm of rational 

 life, and we attempt to philosophize upon them, and seek to discover 

 the presuppositions they involve and to lay bare their governing pur- 

 poses, the mind rests only when answer and illustration are given in 

 the ends toward which they point. 



Even the explanations offered by physical science shed no light upon 

 the inner working of nature. What is called explanation is, as Mi*. 

 Mill admits, " but substituting one mystery for another, and does 

 nothing to render the general coui'se of nature other than mysterious ; 

 we can no more assign a wliy for the more extensive laws than for 

 the partial ones." It might even be contended that until scientific 

 methods take cognizance of final causes, they are not true to that 

 principle of causality upon which they all alike i-est ; for until they 

 do so the phenomenon of repeated co-incidence and co-ordinated action 

 of causes remains unexplained. Even then within the range of 

 inductive science want is felt of some higher explanation. The realm 



