658 THE POPULAR SCIENCE MONTHLY. 



From a distribution of over six hundred copies of a set of questions 

 upon this subject, I have received one hundred and two answers, 

 hirgely from professional men and women, and from the students of 

 the upper classes of our leading American colleges, each paper sub- 

 scribed with the name, age, and address of the sender. In obtaining 

 this mass of material, I have been placed under great obligations to 

 President jMcCosh ; to Professor George P. Fisher, of Yale College ; 

 Professor William James, of Harvard College ; President Robinson, of 

 Brown ; Professor Osborn, of Princeton ; Professor Stanley Hall, of 

 Johns Hopkins ; Dr. Nicholas Murray Butler, of Columbia ; and Pro- 

 fessor Torrey, of the University of Vermont. The healthy, normal side 

 of this subject is the only one I shall attempt to consider, leaving the 

 questions of morbid pathology to those who alone can weigh the evi- 

 dence it throws upon the subject. 



If, in our experience, we witness an effect, we know, by the inex- 

 orable logic of science, that its existence must be due to some efficient 

 cause. "Verily a tree is known by its fruit" is sound teaching and 

 sound sense — it is axiomatic. If a solution of a mathematical prob- 

 lem can really be revealed to us in consciousness, W'hile we are busied 

 about other things, it must inevitably have been performed by means 

 of the processes which regularly lead to such a result, even if we are 

 not conscious at the time of employing such processes. It could not 

 have come spontaneously, but only as the result. As a consequence, 

 in such a case we would be bound to predicate some exercise of intel- 

 lectual powers, actively working during unconsciousness. The circu- 

 lar before referred to comprised eleven questions ; those, the results 

 of which are specially used here, are as follow : 



Second Question. — "1. When you are unable to recall the name of some- 

 thing wanted, and you say, 'Never mind, it will occur to me,' are you conscious 

 of any effort at searching after it? 



"2. When you are, do you feel some trouble or weight in your effort? 



"3. When you are not, does the idea ever, when it occurs, seem to have 

 come back spontaneously, without being suggested by any perceived association 

 of ideas? " 



Third Question. — " During sleep, have you ever pursued a logical, connected 

 train of thought upon some topic or problem in which you have reached some 

 conclusion, and the steps and conclusions of which you have remembered on 

 awakening? " 



Sixth Question. — " 1. Can you wake precisely at a given hour, determined 

 upon before going to sleep, without waking up many times before the appointed 

 time? 



" 2. If you can, then {a) is this habitual, or do you often fail? (?>) Are you 

 conscious, before waking, of any feeling? (describe it), or (c) do you come di- 

 rectly from oblivion into consciousness?" 



Ninth Question. — "When perplexed at your progress in any work (mathe- 

 matical, professional, literary, chess, puzzles, etc.), have you ever left it unfin- 

 ished and turned your attention to other things, and, after some time, on volun- 

 tarily returning to it, have found yourself able at once to satisfactorily master it? " 



