Summing up our outcome so far, we find that general psychology has reached three great principles in its investigation of knowledge. First, we have the combining tendency of the mind, the grouping together and relating of mental states and of things, called _Apperception_. Then, second, there are the particular relations established among the various states, etc., which are combined; these are called _Associations_ of Ideas. And, third, there is the tendency of the mind to use its old experiences and habits as general patterns or nets for the sorting out and distributing of all the new details of daily life; this is called _Assimilation_. II. Let us now turn to the second great aspect of the mind, as general or introspective psychology considers it, the aspect which presents itself in Action or conduct. The fact that we act is of course as important as the fact that we think or the fact that we feel; and the distinction which separates thought and action should not be made too sharp. Yet there is a distinction. To understand action we must again go to introspection. This comes out as soon as we ask how we reach our knowledge of the actions of others. Of course, we say at once that we see them. And that is true; we do see them, while as to their thoughts we only infer them from what we see of their action. But, on the other hand, we may ask: How do we come to infer this or that thought from this or that action of another? The only reply is: Because when we act in the same way this is the way we feel. So we get back in any case to our own consciousness and must ask how is this action related to this thought in our own mind. To this question psychology has now a general answer: Our action is always the result of our thought, of the elements of knowledge which are at the time present in the mind. Of course, there are actions which we do from purely nervous reasons. These are the Instincts, which come up again when we consider the animals. But these we may neglect so long as we are investigating actions which we consider our own. Apart from the Instincts, the principle holds that behind every action which our conduct shows there must be something thought of, some sensation or knowledge then in mind, some feeling swelling within our breast, which prompts to the action.