In the last chapter we discussed only two of the several types of action into which, for convenience, we had classified our general behaviour. We spoke of reflex action and the instinctive actions of animals together because they had one outstanding feature in common, namely, that the organism is somehow equipped with them in a more or less perfect form at birth, that they do not need to be learned. But if we think over our own total behaviour, or, from the standpoint taken in these chapters, that of many animals as well, it becomes evident that such actions in and of themselves constitute a very small part of our active lives. For we must admit that most of the things we do, we have first to learn before they are part of our repertoire. True, we may have built on certain innate capacities, but in the main our intelligent and relevant ways of acting are not ready-made, but are the result of continual modification through trial, error, insight and experience. The study of this achieving, modifying and changing of behaviour, in view of the situation with which we are confronted, is the next general topic on which we must embark in order to give a more complete picture of the psychologist at work.