SCIENTIFIC STUDY OF HUMAN TESTIMONY. 57 



solve, as well as from the narrow strip of territory it has subjected to 

 science the human brain is an organ of very limited capacity. 



If some superior being endowed with superhuman, though not neces- 

 sarily divine powers, should attempt to analyze the mind of man to 

 assign its relative position in creation, and to place it, properly ticketed 

 and labeled, in some supra-terrestrial museum it would be found to be 

 a far less imposing object than man's own imagination has pictured it. 

 If it be claimed, as it may be by some, that although this brain has thus 

 far achieved but little, although, whether considered in the aggregate, the 

 average capacity in many nations and through many generations, or, 

 concretely in cases of individual and exceptional genius as Socrates, 

 Napoleon, Goethe, Newton, Shakespeare it has fallen so far short of its 

 desires and aims and apparent needs as not to merit the encomiums that 

 poets and philosophers have lavished upon it, yet it has before it in this 

 world, and in our present mode of being, a future of possibly infinite 

 development, I may reply that the study of human testimony is in 

 no way affected by such possibility, since it has to do only with the 

 brain in the past, the present, or the near future. 



The whole subject of the limitations of the human brain ' is of 

 high import, is very wide in extent, and suggestive practically as well 

 scientifically and in ways almost innumerable, some of which I hope to 

 point out at a future time ; but, for the present purpose, the recon- 

 struction of the principles of evidence, it is necessary to refer only to 

 the following illustrations : 



1 The number of distinct thoughts of which the mind is capable in a given time is very 

 limited, and can be estimated by experiment with considerable precision. Says Sir Henry 

 Holland : 



" Within a minute I have been able to coerce mind, so to speak, into more than a 

 dozen acts or states of thought so incongruous that no natural association could possibly 

 bring them into succession. In illustration I note here certain objects which, with a watch 

 before me, I have just succeeded in compressing, distinctly and successively, within thirty 

 seconds of time the Pyramids of Gizeh, the ornithorhynchus, Julius Caesar, the Ottawa 

 Falls, the rings of Saturn, the Apollo Belvedere. This is an experiment I have often made 

 on myself, and with the same general result. It would be hard to name or describe the 

 operation of mind by which these successive objects have been thus suddenly evoked and 

 dismissed. There is the volition to change ; but how must we define that effort by which 

 the mind, without any principle of selection or association, can grasp so rapidly a succes- 

 sion of images thus incongruous, drawn seemingly at random from past thought and mem- 

 ories ? I call it an effort because it is felt as such, and cannot be long continued without 

 fatigue. 



" In commenting upon this a writer in Nature says : ' This is a curious subject which 

 easily admits of experiment, but it will be found that the velocity with which thoughts 

 can be made to succeed each other depends entirely upon the degree of similarity or con- 

 nection between them. Judging from my own experience and that of three students well 

 qualified to test the matter, I find that, where the objects thought of are as incongruous as 

 possible, the number which the mind can suggest to itself in a minute varies from twelve, 

 the result of Sir Henry Holland, up to about twenty. Any one who tries the experiment, 

 however, will find that there is an almost insuperable temptation to go off on lines of 

 association. To avoid these, and yet to think rapidly, requires a very disagreeable effort, 

 becoming more and more painful by repetition. When the thoughts are restricted with- 



