The fundamental fact in all ranges of life from the lowest to the highest is _activity_, _doing_. Every individual, either animal or man, is constantly meeting situations which demand response. In the lower forms of life, this response is very simple, while in the higher forms, and especially in man, it is very complex. The bird sees a nook favorable for a nest, and at once appropriates it; a man sees a house that strikes his fancy, and works and plans and saves for months to secure money with which to buy it. It is evident that the larger the possible number of responses, and the greater their diversity and complexity, the more difficult it will be to select and compel the right response to any given situation. Man therefore needs some special power of control over his acts--he requires a _will._ 1. THE NATURE OF THE WILL There has been much discussion and not a little controversy as to the true nature of the will. Just what _is_ the will, and what is the content of our mental stream when we are in the act of willing? Is there at such times a new and distinctly different content which we do not find in our processes of knowledge or emotion--such as perception, memory, judgment, interest, desire? Or do we find, when we are engaged in an act of the will, that the mental stream contains only the familiar old elements of attention, perception, judgment, desire, purpose, etc., _all organized or set for the purpose of accomplishing or preventing some act_? THE CONTENT OF THE WILL.--We shall not attempt here to settle the controversy suggested by the foregoing questions, nor, for immediately practical purposes, do we need to settle it. It is perhaps safe to say, however, that whenever we are willing the mental content consists of elements of cognition and feeling _plus a distinct sense of effort_, with which everyone is familiar. Whether this sense of effort is a new and different element, or only a complex of old and familiar mental processes, we need not now decide. THE FUNCTION OF THE WILL.--Concerning the function of the will there can be no haziness or doubt. _Volition concerns itself wholly with acts, responses._ The will always has to do with causing or inhibiting some action, either physical or mental. We need to go to the dentist, tell some friend we were in the wrong, hold our mind to a difficult or uninteresting task, or do some other disagreeable thing from which we shirk. It is at such points that we must call upon the will. Again, we must restrain our tongue from speaking the unkind word, keep from crying out when the dentist drills the tooth, check some unworthy line of thought. We must here also appeal to the will. We may conclude then that the will is needed whenever the physical or mental activity must be controlled _with effort_. Some writers have called the work of the will in compelling action its _positive_ function, and in inhibiting action its _negative_ function.