188 ■ SECTIONAL ADDRESSES. 



(d) to prohibit the observer from being doubtful. 



Now all these devices ignore the very points which are psychologically 

 the most interesting and important. First they tend to treat each 

 judgment in the series as equally and independently significant, the 

 function of the immediate stimulus. This is certainly wrong. For 

 example, Wundt demonstrated long ago that a given judgment may 

 express, not the immediate effect of its stimulus, but the cumulative 

 result of a series of preceding stimuli and situations no one of which at 

 once issues in a characteristic overt response. Again and again the status 

 of a pronouncement in a series has been shown to depend on its order of 

 presentation within that series. Secondly, no judgment of this type is the 

 expression of a simple stimulus-response situation, but of a stimulus- 

 attitude-response situation. To demand guesses and to prohibit doubt 

 both alike determine an attitude of observation which spreads over the 

 whole experimental situation, affecting judgments which are assigned 

 certainty just as much as the others. During a few years preceding the war 

 a number of extremely interesting experiments were carried out, par- 

 ticularly by Dr. Fernberger, upon the effect of ' attitude ' in determining 

 judgments obtained by psychophysical methods. For some reason these 

 have never been adequately followed up, but they represent what I take 

 to be a genuine problem of the experimentalist in psychology. In this 

 case the question is : How are the judgments obtained in the various 

 psychophysical methods determined ? It is not enough to correlate 

 immediate stimulus variations with immediate characters of response, or 

 simply to describe the immediate response mechanism that is brought into 

 play. When an observer enters into an experimental situation he brings 

 with him propensities, tendencies, preformed organised systematic modes 

 of response, the preformed cumulative organised effect of a mass of past 

 discriminations. The stimulus, the situation that is presented, hits off 

 some of these. They appear in him as an ' attitude,' and it is imder the 

 active control of this that he makes his responses. Only when we know 

 more about how this is set up and about its precise effect upon the responses 

 made, can we safely give to the latter the necessary weighting which 

 makes their statistical treatment genuinely significant. I think that the 

 psychophysical methods, studied from this point of view, will yet yield 

 some enormously important results. 



If the physicist in his approach to the stimulus-reaction type of problem 

 tends to treat the stimulus regarded objectively as the main point of interest, 

 the physiological method of approach is equally bound to concentrate its 

 attack upon the immediate functional mechanism. It is of course foolish 

 to argue, as is often done, that the physiologist is absolutely confined to a 

 study of local response mechanisms, treating it as a matter of indifference 

 whether they are in or out of their wider organic setting. But he does 

 rightly lay the chief emphasis upon these, and for obvious and just reasons 

 shrinks from speculation about central processes until he knows as much as 

 can be learned about the peripheral functions and their mode of operation. 

 From the earliest days up to the present a great part, perhaps the greatest 

 part, of experimental psychology has been concerned with special sense 

 reactions. Yet the psychologist has never staked out clearly any mode of 

 investigation or characteristic problems which are specially his own in this 



i 



