SCIENTIFIC STUDY OF HUMAN TESTIMONY. 177 



Not only is it possible for a single individual to be deceived by mis- 

 taking subjective for objective impressions, but, as 1 have proved by re- 

 peated experiments, the details of which have already been published, it 

 is possible and easy to cause a large number of individuals, of intelli- 

 gence and in good health, to see simultaneously the same subjective 

 visions without any of them being able to detect the deception. Such 

 experiences of the simultaneous confounding of the subjective with the 

 objective are not exceptional to the degree that we might suppose ; 

 they are frequently occurring, and can be verified without difficulty by 

 those who are trained to the art of experimenting with living human 

 beings. All situations and experiences that excite the emotions of awe, 

 of wonder, or reverence, or fear, or expectation, either singly or in com- 

 bination, are liable to produce subjective visions that may appear at the 

 same time and in the same form to large numbers of people, not one of 

 whom shall be able, without external aid, to recognize the deception; 

 and when these various emotions, powerfully aroused, do not thus cause 

 impressions to be absolutely originated on the retina, they may, and 

 often do, so modify the impressions made by objects to which the eyes 

 and the attention are directed as to give rise to delusions that are both 

 absolute and absurd, and out of which the subjects, though perfectly 

 sane and sound, and, it may be, also scholarly, and accomplished, and 

 scientific, can never be reasoned. 



Delusions from this cause are in part, though not entirely, the origin 

 of the myths, the legends, and the traditions, of what is called history, 

 and are constant and oftentimes fatal elements of error in all historical 

 criticism. The science of history will never attain the precision of which 

 it is capable until the chaff of the subjective is winnowed from the wheat 

 of the objective ; until it is recognized as a physiological and pathologi- 

 cal fact that the seeing of any object by any number of honest and in- 

 telligent people is no necessary evidence of the existence of that object; 

 and, until it is understood that the claims of what is seen by individuals 

 or by multitudes, all concurring in their testimony, are to be determined, 

 if determined at all, only by reasoning deductively from the known cir- 

 cumstances under which the claims were made, and from general prin- 

 ciples of science previously established. 1 Yet further, it must be under- 



1 Gibbon's " History of the Decline and Fall of the Roman Empire," for example, con- 

 tains a vast number of statements and discussions which, scientifically, are of no value, and 

 iudeed by no manner of possibility could have any value. Details of expressions and 

 actions, which, when obtained directly from the authors, must have been largely untrue, 

 become, when filtered down the centuries through armies of non-experts, but the counter- 

 feit of human experience a satire on history. The historical writings of Prescott and of 

 Irving are especially open to this criticism, and should be commended to the young with 

 the suggestion, always, that they are to be considered as fiction ; indeed, the best novels 

 are better histories than much of professed history, since they do not attempt the impos- 

 sible burden of carrying exact details, but merely aim to teach general facts, principles, 

 and events, concerning which a certain degree of truth is sometimes attainable. 



A volume of historical criticism is suggested by the following admission of Carlyle in 

 VOL. xiii. 12 



