Full Idea
'Right' does not mean the same as 'morally good'; we cannot substitute 'he is a right man' for 'he is a morally good man'; this is not just an English idiom, as it is clear that a 'right act' is the act which ought to be done.
Gist of Idea
'Right' and 'good' differ in meaning, as in a 'right action' and a 'good man'
Source
W. David Ross (The Right and the Good [1930], §I)
Book Reference
Ross,W.David: 'The Right and the Good' [OUP 1930], p.3
A Reaction
This is nowadays accepted as a basic distinction in ethical discussions. Shooting a prisoner might be the right thing to do, but it is unlikely to be good. We may talk of 'good deeds', but never of 'right' people.