We have seen that a certain sort of parallelism is involved in the attempt to state the experience of the individual in so far as it is peculiar to him as an individual. What is accessible only to that individual, what takes place only in the field of his own inner life, must be stated in its relationship to the situation within which it takes place. One individual has one experience and another has another experience, and both are stated in terms of their biographies; but there is in addition that which is common to the experience of all. And our scientific statement correlates that which the individual himself experiences, and which can ultimately be stated only in terms of his experience, with the experience which belongs to everyone. This is essential in order that we may interpret what is peculiar to the individual. We are always separating that which is peculiar to our own reaction, that which we can see that other persons cannot see, from that which is common to all. We are referring what belongs to the experience just of the individual to a common language, to a common world. And when we carry out this relationship, this correlation, into what takes place physically and physiologically, we get a parallelistic psychology.
The particular color or odor that any one of us experiences is a private affair. It differs from the experience of other individuals, and yet there is the common object to which it refers. It is the same light, the same rose, that is involved in these experiences. What we try to do is to follow these common stimuli in through the nervous system of each of these individuals. We aim to get the statement in universal terms which will answer to those particular conditions. We want to control them as far as we can, and it is that determination of the conditions under which the particular experience takes place that enables us to carry out that control.
If one says that his experience of an object is made up of different sensations and then undertakes to state the conditions under which those sensations take place, he may say that he is stating those conditions in terms of his own experience. But they are conditions which are common to all. He measures, he determines just what is taking place, but this apparatus with which he measures is, after all, made up of his sensuous experience. Things that are hot or cold, rough or smooth, the objects themselves, are stated in terms of sensations; but they are stated in terms of sensations which we can make universal, and we take these common characters of experience and find in terms of them those experiences which are peculiar to the different individuals.
Psychology is interested in this correlation, in finding out what the relationship is between what goes on in the physical world and what goes on in the organism when a person has a sensory experience. That program was carried out by Hermann Helmholtz. The world was there in terms which could be stated in the laws of science, i.e., the stimuli were stated in physical terms. What goes on in the nervous system could be stated more and more exactly, and this could be correlated with certain definite experiences which the individual found in his own life. And the psychologist is interested in getting the correlation between the conditions under which the experience takes place and that which is peculiar to the individual. He wishes to make these statements as universal as possible, and is scientific in that respect. He wants to state the experience of an individual just as closely as he can in terms of the field which he can control, those conditions under which it appears. He naturally tries to state the conduct of the individual in terms of his reflexes, and he carries back as far as he can the more complex reflexes of the individual to the simpler forms of action. He uses, as far as he is able to use, a behavioristic statement, because that can be formulated in terms of this same field over which he has control.
The motive back of modern psychology gets an expression in the field of mental testing, where one is getting correlations between certain situations and certain responses. It is characteristic of this psychology that not only is it as behavioristic as it can be (in that it states the experience of the individual as completely as it can in objective terms), but it also is interested in getting such statements and correlations so that it can control conduct as far as possible. We find modern psychology interested in practical problems, especially those of education. We have to lead the intelligences of infants and children into certain definite uses of media, and certain definite types of responses. How can we take the individual with his peculiarities and bring him over into a more nearly uniform type of response? He has to have the same language as others, and the same units of measurement; and he has to take over a certain definite culture as a background for his own experience. He has to fit himself into certain social structures and make them a part of himself. How is that to be accomplished? We are dealing with separate individuals and yet these individuals have to become a part of a common whole. We want to get the correlation between this world which is common and that which is peculiar to the individual. So we have psychology attacking the questions of learning, and the problems of the school, and trying to analyze different intelligences so that we can state them in terms which are as far as possible common; we want something which can correlate with the task which the child has to carry out. There are certain definite processes involved in speech. What is there that is uniform by means of which we are able to identify what the individual can do and what particular training he may have to take? Psychology also goes over into the field of business questions, of salesmanship, personnel questions; it goes over into the field of that which is abnormal and tries to get hold of that which is peculiar in the abnormal individual and to bring it into relation with the normal, and with the structures which get their expression in these abnormalities. It is interesting to see that psychology starts off with this problem of getting correlations between the experience of individuals and conditions under which it takes place, and undertakes to state this experience in terms of behavior; and that it at once endeavors to make a practical use of this correlation it finds for the purposes of training and control. It is becoming essentially a practical science, and has pushed to one side the psychological and philosophical problems which have been tied up with earlier dogma under associational psychology. Such are the influences which work in the behavioristic psychology.
This psychology is not, and should not be regarded as, a theory which is to be put over against an associational doctrine. What it is trying to do is to find out what the conditions are under which the experience of the individual arises. That experience is of the sort that takes us back to conduct in order that we may follow it. It is that which gives a distinctive mark to a psychological investigation. History and all the social sciences deal with human beings, but they are not primarily psychological. Psychology may be of great importance in dealing with, say, economics, the problem of value, of desire, the problems of political science, the relation of the individual to the state, personal relations which have to be considered in terms of individuals. All of the social sciences can be found to have a psychological phase. History is nothing but biography, a whole series of biographies; and yet all of these social sciences deal with individuals in their common characters; and where the individual stands out as different he is looked at from the point of view of that which he accomplishes in the whole society, or in terms of the destructive effect which he may have. But we are not primarily occupied as social scientists in studying his experience as such. Psychology does undertake to work out the technique which will enable it to deal with these experiences which any individual may have at any moment in his life, and which are peculiar to that individual. And the method of dealing with such an experience is in getting the conditions under which that experience of the individual takes place. We should undertake to state the experience of the individual just as far as we can in terms of the conditions under which it arises. It is essentially a control problem to which the psychologist is turning. It has, of course, its aspect of research for knowledge. We want to increase our knowledge, but there is back of that an attempt to get control through the knowledge which we obtain; and it is very interesting to see that our modern psychology is going farther and farther into those fields within which control can be so realized. It is successful in so far as it can work out correlations which can be tested. We want to get hold of those factors in the nature of the individual which can be recognized in the nature of all members of society but which can be identified in the particular individual. Those are problems which are forcing themselves more and more to the front.
There is another phase of recent psychology which I should refer to, namely, configuration or gestaltpsychology, which has been of interest in recent years. There we have the recognition of elements or phases of experience which are common to the experience of the individual and