Asallpotenciesareeitherinnate，likethesenses，orcomeby
practice，likethepowerofplayingtheflute，orbylearning，like
artisticpower，thosewhichcomebypracticeorbyrationalformulawe
mustacquirebypreviousexercisebutthisisnotnecessarywiththose
whicharenotofthisnatureandwhichimplypassivity。