47o POPULAR SCIENCE MONTHLY 



the two remaining ones have peculiarities which greatly restrict their 

 significance. Indeed, a moment's reflection would be sufficient to con- 

 vince one that things are not as bad as they look through the profes- 

 sional glasses of Professor Munsterberg. If our immediate perception 

 of the things around us, or even our judgment of times, distances, 

 velocities, etc., were as desperately deficient as the whole tenor of Pro- 

 fessor Miinsterberg's article implies, the world could not be carried on 

 as it is. Business transactions take place every day by the hundred 

 million' which turn on the unhesitating recognition of a rarely seen 

 face, and the number of cases of mistaken identity is infinitesimal in 

 comparison; we cross in front of trolley-cars and automobiles and 

 bicycles millions of times just near enough to escape being run over, 

 to once that we actually get run over. To translate that fine judgment 

 of time and distance which brings us safely across Broadway into terms 

 of feet and seconds is a task that most of us perform extremely ill; 

 but this is a particular matter affecting the value of testimony of a 

 special kind, and not touching the general reliability of human observa- 

 tion. This latter is itself undoubtedly highly impeachable; but Pro- 

 fessor Miinsterberg's tests add little, if anything, to the impeachment. 

 But there is another side to Professor Miinsterberg's article. It is 

 designed not only to show how frequently observation is untrustworthy, 

 but also to advocate a method of classification of witnesses by which the 

 trustworthy ones may be separated from the untrustworthy. " The 

 progress of experimental psychology," he says, " makes it an absurd 

 incongruity that the state should devote its fullest energy to the clear- 

 ing up of all the physical happenings, but should never ask the psy- 

 chological expert to determine the value of that factor which becomes 

 most influential — the mind of the witness." That an appeal to psy- 

 chological experts may in certain special cases be necessary or desirable 

 I do not at all wish to deny; but it seems very clear to me, from the 

 evidence of Professor Miinsterberg's own paper, that any attempt to 

 introduce psychological tests as a regular part of the machinery of 

 courts in their dealings with witnesses would be utterly futile. It is 

 conceivable that psychological experts who combined the highest scien- 

 tific attainments with the most consummate common sense, and the 

 greatest precision of reasoning with the utmost practical caution and 

 shrewdness, could, by subjecting a witness to a sufficiently compre- 

 hensive examination, arrive at an authoritative determination of the 

 weight that ought to be attached to his account of the facts which he 

 alleges to have come under his observation ; but nothing short of this 

 would suffice. The difficulties in the way are many and great; but 

 first and foremost among them comes the distinction between a labora- 

 tory experiment and the involuntary or unregulated experience of real 

 life. Certainly accuracy of observation, whatever other elements it 

 turns on, turns very largely on the question of attention or interest; 



