682 EXPERIMENTAL PSYCHOLOGY 



Let us realize that we may attempt here any one of three distinct 

 problems. We may aim at a psychology of memory and association; 

 i. e., we may seek to record our experience, to trace the introspect- 

 ive patterning of the memory-consciousness. We may aim at a 

 psycho-physics of memory; i. e., we may try to establish formulae 

 akin to the well-known formula of Ebbinghaus's Geddchtnis, which 

 represents retention as a function of time elapsed. Or we may aim 

 at an applied psychology of memory; we may work out, experi- 

 mentally, an art of acquisition. I do not say that an investigation 

 into one of these three topics will throw no light on the other two; 

 on the contrary, I have already insisted on the value of indirect 

 results in psychological inquiries. But in our thought, at any rate, 

 the three problems should remain separate and distinct. They offer, 

 without doubt, a wide field for future research. I would suggest, 

 though with all reserve, that the psychological study of memory 

 and association may, in the long run, help us to clear up the much- 

 disputed question of the subconscious. There are, as you know, 

 experimental psychologists who work simply in terms of introspec- 

 tion and of physiological process; there are others who interpolate 

 between these terms an unconscious or subconscious mentality. I 

 cannot go into detail; but it seems to me that, if these differences 

 of opinion can in any connection be brought into the laboratory 

 for adjustment, it is here, in the investigation of memory and 

 association, that we may hope to introduce them. 



I come next (6) to action. You will remember that, in its early 

 years, experimental psychology was much concerned with the psycho- 

 physics of action; indeed, the problem of the " personal equation" 

 is a good deal older than our laboratories. This interest has never 

 nagged. If we have not heard so much of late about reaction ex- 

 periments, we have heard a great deal about the psycho-physiology 

 and psycho-physics of voluntary movement. And I think that we 

 can leave these things to take care of themselves; we may, without 

 any question, look to the next few years for improvements of tech- 

 nique, for revision of numerical determinations, for recasting of 

 theories. That work is under way. What I should like now to em- 

 phasize is the need for investigation of the more strictly psycho- 

 logical kind. Our knowledge of the action-consciousness is still very 

 schematic, very rough, in part very hypothetical. It has been re- 

 cognized for some years that the reaction experiment may be turned 

 to qualitative, i. e., to analytical account; but so far more use has 

 been made of this idea in laboratory practice than in research. We 

 must start all over again, and take the action-consciousness seriously. 

 I once made a sort of reaction experiment of the setting-up and 

 taking-down of an inductorium; the student made the manipula- 

 tions continuously, under time-control, and gave his introspective 



