无动机的
Motiveless \Mo"tive*less\, a. Destitute of a motive; not incited by a motive. -- {Mo"tive*less*ness}, n. --G. Eliot.
motiveless adj : occurring without motivation or provocation; "motiveless malignity"; "unprovoked and dastardly attack"- F.D.Roosevelt [syn: {unprovoked}, {wanton}]