motive 
英 [ˈməʊtɪv]  美 [ˈmoʊtɪv] 
n. 动机，目的；主题

v. 促使，激起

adj. 发动的；成为动机的

例句：
Profit, he insisted, was never his motive. 

他坚称，他从来没想过从中获利。

the motives and objectives of British foreign policy 

英国外交政策的动机及目标

One might question the motives of some politicians. 

有人也许会质疑一些政客的动机。

I urge you to question his motives. 

我强烈要求你对他的动机提出质疑。

Police have ruled out robbery as a motive for the killing. 

警方已排除因抢劫而杀人的可能。