Which preposition to use with unrighteous

in Occurrences 3%

Of all the cruelties inflicted by society, there is none so unrighteous in its nature as the stigma it entails in the succession of crime or misfortune: of all its favors, none can find so little justification, in right and reason, as the privileges accorded to the accident of descent.

from Occurrences 1%

I will not now dissect my motive, but it was vaguely connected with my mission, and not unrighteous from that standpoint.

Which preposition to use with  unrighteous