WordNet sense 1 (an efficient incentive):

moral force

WordNet sense 2 (having the power of driving or impelling):

driving

WordNet sense 3 (marked by continuous change or effective action):

changing

WordNet sense 4 (characterized by action or forcefulness or force of personality):

dynamical

WordNet sense 5 (expressing action rather than a state of being; used of verbs (e.g. `to run') and participial adjectives (e.g. `running' in `running water')):

active