A second phenomenon of practice is the simplification of the conscious processes preceding purposive action. Unless there are particular causes, as anticipatory ideas or an extraordinary special interest, that which has often occurred tends to remain unconscious, so that the response may be called automatic. The ticking of a clock, the noise of a street, the laughing of a mountain stream, soon cease to be attended to, although attention to them is always possible. Reading, writing, arithmetical work, when being learned, include a vast number of states of consciousness which no longer occur when these activities are performed by a grown person. After thousand-fold repetition great rapidity of execution results from the omission of a multitude of mental states without which the performance could not originally have been brought about. But the original effects of those lost mental states are not at all lost. The same movements are carried out with the same accuracy as if they were governed by those mental states. Each single letter, even each word, is not found in the consciousness of a person who reads rapidly, and yet he pronounces the word correctly. Each single note or printed chord is not in the consciousness of the pianist, and yet he plays the chord correctly. The same holds for all complex movements that are slowly learned and often repeated, as knitting, sewing, swimming, horseback riding, dancing, skating. They finally require a minimum of mental energy. They become comparable in this respect to the native, instinctive movements; but in order to distinguish them from the native movements independent of consciousness, we call them automatic movements. Practice, therefore, is a general term referring to the wonderful adaptation of mind to the external world for the purpose of self-preservation. By association and reproduction mind adapts itself to frequently recurring events and anticipates them. By practice it adapts itself to those events which recur with particular frequency and which are of particular importance. These events are through practice comprehended more delicately, more quickly, and more inclusively. They are responded to in a manner tested as the most fitting and most prompt, and yet requiring only a minimum of mental energy, of which more than a limited amount is at no time available. Without having to neglect the ordinary and as such important, mind has energy left to devote to that which is new, unusual, surprising. QUESTIONS 104. What are the effects of practice on sense perception? 105. Illustrate how practice simplifies thought. § 11. FATIGUE