remarked, earlier in this lecture, that Wundt has made significant use, in his theory of emotion, of the temporal aspect of mental processes; and I think that the future experimenter will do well to take the hint. But we cannot analyze emotion and sentiment, with any prospect of final success, until we are agreed upon the nature and number of the affective qualities.
It is a relief to turn from these topics, of imagination and emotion, to the problem (9) of thought. We have found various things that may with some truth be called 'characteristic' of the experimental psychology of the last ten years: the revival and extension of psychophysics, the focalizing of the affective problem, the emergence of a tangible psychology of attention, the establishment of the laws of memory. Nevertheless, if I were asked to name a single line of investigation that, more than any other, has characterized the decennium, I should not hesitate to select the experimental studies of the thought-processes, most of which we owe to the Würzburg laboratory. Not that these researches have been confined to Germany: on the contrary, Binet in France, Woodworth in the United States, Bovet in Switzerland, as well as Marbe and his successors at Würzburg, have all attacked the same problem; though it is true that the German work has been the most thorough and the most persistent. Here is a new departure in experimental psychology; concept and judgment and inference, the last refuge of the rational psychologist, have been ranged alongside of sensation and association, introspectively analyzed and made subject to the chronoscope. I shall endeavor, in my next Lecture, to give you some idea of methods and results, and to point out the most promising paths of future enquiry.
So I finish the principal part of my review. If I have omitted anything of consequence, or if I have seemed to do injustice to any department of work, I must ask for pardon and correction; I have spoken with the utmost possible brevity. It remains, now, to say something of the extensions of the experimental method beyond the limits within which the present discussion has moved. What of individual psychology; of the psychology of the minor abnormalities—sleep, dreaming, hypnosis; of experimental æsthetics? What, last but not least, of comparative psychology?
I have time only for a word or two. Individual psychology, which was first systematized by Stern in 1900, is, in its modern form, one of the chief witnesses to the value of experiment. It furnishes the key to many, otherwise inexplicable differences of result, and it promises to allay many of the standing controversies of the text-books; there can be no
