rational motive - a motive that can be defended by reasoning or logical argument

dynamic, moral force - an efficient incentive; "they hoped it would act as a spiritual dynamic on all churches"

causation, causing - the act of causing something to happen

corruption - inducement (as of a public official) by improper means (as bribery) to violate duty (as by commiting a felony); "he was held on charges of corruption and racketeering"