ABSTRACT
It is often asserted that every science should be built up on a foundation of clear and sharply-defined basic concepts. Psychologists then go on to group, classify, and correlate what they have described. Even at the initial stage when psychologists are describing their material, it is impossible to avoid applying to it certain abstract ideas. When at last they have done all this it may be time to crystallize them in definitions. In psychology a conventional and indispensable, but still rather obscure, basic concept is that of instinct. This chapter explores what this concept covers by approaching it from different angles. It soon begins to make a first discrimination and a first orientation. The aim of every instinct is to obtain satisfaction. This can only be done by ending the state of stimulation in the source of the instinct. The aim of the first is to bind together, and the second is to undo connections and so to destroy.
