the psychological feature that arouses an organism to action toward a desired goal; the reason for the action; that which gives purpose and direction to behavior
Needs and interests are the motivations that induce society to develop. 需要和利益是社会发展的动因。
The motivations for grammaticalization are studied and an interpretation for its cognitive and pragmatic motivations is given. 从隐喻等认知因素和经济原则等语用因素入手，对语法化的动因进行阐释。
