Jan. lo, 1889] 



NATURE 



245 



the sense-organ, for their part, if not whole, funclion in 

 the perceptive act is mediatorial. 



Argument 2 : " The view that the memory of an im- 

 pression occupies a part of the brain distinct from the 

 perception is simpler and more consistent than super- 

 adding the function of memory to that of some of the 

 faculties. Thus, why should the instinct to acquire and 

 its special memory occupy different portions of the brain, 

 whilst the perception of a form and its memory occupy 

 the same portion ? " But who but our author alleges that 

 they do occupy different portions .' 



Most of the other arguments turn upon the implica- 

 tions of the faculty-hypothesis, and lose whatever force 

 they seem to possess by the abandonment of that mode 

 of conceiving mental phenomena. Thus, No. 5 : " The 

 absolute impossibility of understanding how an impres- 

 sion could be split up, so that each faculty might take its 

 share of an impression." Material separation of faculty- 

 areas apart, one does not readily see the point of this 

 difficulty. 



Our author says : " I will take for illustration the 

 faculty of colour, as being the very simplest possible ; but 

 by.no stress of imagination can I conceive how an im- 

 pression of colour can exist, apart from the impression 

 itself, to be of any definite use in remembrance." The 

 reader's imagination will very likely be as much taxed 

 as the writer's ; indeed, he will probably vainly try to 

 imagine what the author is exerting himself to imagine. 

 After much straining, I seem to myself to seize the 

 intended meaning in the following rendering. The mind 

 being regarded as an aggregate of distinct faculties, the 

 matter of any impression will be simultaneously appre- 

 hended by several. Now the energy of a faculty is a 

 function of the hemispheres. But that which is common 

 to several faculties cannot be the exclusive property of 

 any one. In remembering, the perceiving faculty is 

 dormant ; therefore, in remembering, some other region 

 of the brain must be excited. — But how if the initial 

 assumption be denied, and memory of the perception be 

 no other than the perception minus the outlook .'' Is this 

 not sufficiently proved by the fact that there can be no 

 memory' where there never was presentation ; and that 

 remembered presentation can, in certain circumstances, 

 attain the intensity of original presentation? 



But if mental revival be not the subjective concomitant 

 of renewed cerebral agitation of a definite kind, how 

 ought we to conceive the state of the case ? 



Thus : " all sensory impressions, whether elaborated 

 by the faculties of the mind situate in the cerebral hemi- 

 spheres or by the sensory nerves, are permanently stored 

 up in the optic thalami, and constitute the sensory 

 memory" — the equivalent of psychical retentiveness. 

 Then these stored-up impressions find a way out of their 

 hiding-places through one of two opportunities. Either 

 when some similar impression passes "through the 

 sensory memory centre on its way up to the mind " 

 (= remembrance) ; or " through the intervention of the 

 mind" ( = recollection). The writer shows no signsof having 

 thought out all that his descriptions imply. As for the 

 relegation of the function of memory to the basal ganglion, 

 nothing deserving the name of evidence is forthcoming. 



In his treatment of memory in the strictly subjective 

 aspect, Mr. Edridge-Green shows to more advantage. 



although a certain want of lucidity here as elsewhere 

 forms a serious defect. He instances three laws of 

 remembrance, which must be given in his own words : — 



First Law. — " All impressions tend to revive those of a 

 similar character previously received ; but an impression 

 in the sensory memory will not be brought before the 

 consciousness if its psychical intensity does not reach a 

 certain definite standard. This psychical intensity is 

 attained by the association of impressions representing 

 similar members of a psycho- physical series contiguously 

 combined in a similar manner." 



The law seems to amount to this : As the points of 

 similarity in two impressions, one old and one new, 

 increase, is the chance of recognition increased. So 

 interpreted, it is the equivalent of what is frequently 

 called by psychologists the law of Similarity. The law as 

 stated by our author involves, however, his third law, or 

 that familiarly known as the law of Contiguity. 



The similarity referred to in the first law detached from 

 contiguous association is made the subject of the second 

 law of remembrance, which runs — 



"When an impression is received similar to one 

 received previously, unless the previous impression be 

 revived at the same time, both impressions will remain 

 separate ; whereas if the previous impression be brought 

 before the consciousness and recognized as similar, an 

 association of the two impressions will take place." 



The implication of this law is that the similarity of im- 

 pressions alone does not suffice for revival. Over and 

 above the resemblance of the impressions themselves 

 there must be a perception of the resemblance. One 

 would have thought, indeed, that this went without saying. 

 Physical similarity or even identity is not conscious per- 

 ception of resemblance. The students who did not recog- 

 nize the leaf of a plane-tree, although they had been 

 staring at it every day of their lives, had never had in the 

 psychological sense an " impression " of the plane-leaf. 

 The image on the retina preceded no mental image ; and 

 when their attention was called to the plane-leaf, they 

 may be said to have then seen it for the first time. But 

 having cognized it once, they cognized it always, 

 according to a well-known dictum that cognition and 

 re-cognition are one and the same. 



This second law is no pure law of remembrance, then, 

 but a fundamental condition of knowing. 



Third Law. — "The revival of a component of an im- 

 pression tends to the revival of the remaining com- 

 ponents, and the revival of any impression tends to the 

 revival of other impressions received about the same 

 time ; but unless these reach the necessary standard of 

 psychical intensity, they will not be brought before the 

 consciousness." 



This is a not unhappy wording of the great law of 

 mental association, the "law of contiguity." 



As a statement of principles, whether physiological or 

 psychological, I cannot hold this book on the mysterious 

 subject of Memory to be a valuable contribution to 

 scientific literature. There is evidence throughout of 

 first-hand observation and of genuine effort to acquire an 

 original comprehension of both physical and psychical 

 phenomena, but the materials are ill-arranged, and the 

 theorizing crude or mistaken. It might be well if the 

 author, before pursuing his inquiries in this field, made 



