SCIENTIFIC STUDY OF HUMAN TESTIMONY. 55 



testimony of witnesses depends upon, firstly, their honesty ; secondly, 

 their ability ; thirdly, their number and the consistency of their testi- 

 mony; fourthly, the conformity of their testimony with experience; 

 and, fifthly, the coincidence of their testimony with collateral circum- 

 stances." Here we observe that honesty is placed before ability, while 

 under ability no distinction is drawn between general and special abil- 

 ity in other words, between the non-expert and the expert. In the 

 formulated statement of the principles of evidence from which this ex- 

 tract is taken, not only is there no distinction made between expert and 

 non-expert, but no recognition of the fact that the senses of honest and 

 unbiased witnesses may be, through a variety of causes, untrustworthy. 



The mistakes in the administration of justice are already numerous, 

 but they would have been more so if judges and juries had not in- 

 stinctively rejected the principles of evidence thus taught by the high- 

 est authorities in jurisprudence. 



All modern science is the product of exclusively expert evidence : 

 until an expert develops, there can indeed be no science ; and yet, one 

 may look in vain through all the authors on logic for a satisfactory 

 definition of an expert, or for any detailed arrangement of tests by 

 which expertness is to be estimated. 



The subject of human testimony has, in short, never been scientifi- 

 cally studied ; practical rules for the guidance of those who employ it 

 are all that either logic or law has yet given to the world. As some of 

 these practical rules are based on incorrect assumptions in regard to 

 the value of human testimony, they frequently lead to serious error, and, 

 as they fail to draw just distinctions between the good and bad in evi- 

 dence, or to give special suggestions for special cases, they are often- 

 times of no assistance whatever. This criticism is not made in the wav 

 of complaint, for only within the past few years has it been possible to 

 even begin the scientific study of human testimony, while nearly all of 

 our writers on this subject belong to the past generations, 1 and the few 

 later authors mostly copy the errors and imperfections of their prede- 

 cessors. 



Human testimony comes from the human brain : the scientific 

 study of human testimony is only possible through a knowledge of the 

 human brain in health and disease, and is therefore a department 

 of cerebro-physiology and pathology. Only recently have the laws of 

 cerebro-physiology and pathology been sufficiently understood, even by 



1 It may perhaps be objected to this statement that many so-called apologetic and 

 skeptical writings are of recent date; but writers of this class, on both sides, as well as 

 the controversialists on the spiritualism question, assume, without discussion, the princi- 

 ples of evidence as taught in logical and legal text-books. On every page of the writings 

 of the Tubingen school, as De Wette, Bauer, Paulus, Straus, as well as of their opponents 

 in Germany and in the Bampton Lectures, we find evidences of the imperative need of a 

 reconstruction of the principles of evidence. This need is fully admitted by the late Mr. 

 Mozley, in the preface to the third edition of his " Lectures on Miracles." 



