Full Idea
The motive has nothing to do with the morality of the action, though much with the worth of the agent.
Gist of Idea
Motive shows the worth of the agent, but not of the action
Source
John Stuart Mill (Utilitarianism [1861], Ch.2)
Book Reference
Mill,John Stuart: 'Utilitarianism (including On Liberty etc)', ed/tr. Warnock,Mary [Fontana 1962], p.270