impulsion
/ɪmˈpʌlʃən/noun
1- a strong urge to do something冲动：
the impulsion of the singers to govern the pace.
歌手们想控制节奏的冲动。
1.1
- mass noun the force or motive behind an action or process动力, 动机：
attitudes changed under the impulsion of humanitarian considerations.
出于人道主义考虑, 态度发生了改变。
词源
late Middle English （in the sense 'the act or an instance of impelling'）： via Old French from Latin impulsio （n-）， from the verb impellere （see IMPEL）.