Only those experiences are valuable that in an appreciable degree modify future action. One way in which an experience or a series of experiences modifies future action is in the formation of habits. _Habit Formation_ Habit has a beneficial influence on future action in five particulars:-- <p 284> (_a_) Habit reduces the necessary time of action. Repeating the twenty-six letters of the alphabet has become so habitual that I can repeat them forward in two seconds. To repeat them in any other than an habitual order, _e.g_. backwards, requires sixty seconds. (_b_) Habit increases accuracy. I can repeat the alphabet forward without danger of error, but when I try to repeat it backward I am extremely likely to go astray. (_c_) Habit reduces the attendant exhaustion. Reading English is for me more habitual than reading French. Hence the latter is the more exhausting process. (_d_) Habit relieves the mind from the necessity of paying attention to the details of the successive steps of the act. When piano playing has been completely reduced to habit, the finger movement, the reading of the notes, etc., are all carried on successively with the minimum of thought. (_e_) Habit gives a permanency to experience. For many years in playing tennis I served the ball in a way that had become for me perfectly <p 283> habitual. For an interval of three years I played no tennis, but when I began again I found that I could serve as well as ever. If the manner of service had not been so perfectly reduced to habit, I would have found after an interval of three years that I was completely out of practice, _i.e_. that my previous experience did not have a permanent value. (The subject of habit formation will be more completely presented in Chapter XIII.) A second form of experience that is capitalized and so predetermines a man's capacity to act and to think is the formation of what is known as practical judgments. _Practical judgments_ By a practical judgment is meant the conscious recall of a concrete past experience and the determination of some action by means of this consciously recalled event. I find that it will be necessary for me to secure a new stenographer. I solve the problem by consciously recalling how I got one before. Upon the basis of that consciously recalled previous <p 286> experience I decide how to act now. This is a practical judgment. In strictness what is capitalized is not the practical judgment itself but the original concrete experience that is recalled at a later time, and upon the basis of which a practical judgment is formed.