From the previous lectures in this course you have heard in considerable detail something of the more important respects in which psycho-analysis has contributed to our knowledge of social-psychological problems. From this final lecture, which is intended to some extent as a summary of the others, you may well wish to gather some hints of a practical nature about what it is desirable to do in the way of dealing with these problems. Science, however, has a tantalizing way of refusing to answer questions of this sort, rightly regarding them as outside its sphere when cast in such a form, and confining itself to stating—whenever it can—what measures have to be adopted to achieve such and such an effect, granted that someone desires to achieve that particular effect. Psychological science goes even further on this annoying path and, turning on the questions themselves, converts them into an object of study for its own purposes. Instead of answering the question, it proceeds to take an interest in the reasons for asking it and the motives behind the wish to answer it.