So far as upright people are concerned, an advantage (2,3,4)
I believe the answer is:
to the good
'so far as upright people are concerned an' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'advantage' is the wordplay.
I cannot quite see how this works, but
'advantage' could be 'good' (good is a kind of advantage) and 'good' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for to the good that I've seen is " offering a benefit".)