From The Collaborative International Dictionary of English v.0.48 :
Rightfulness \Right"ful*ness\, n.
1. The quality or state of being rightful; accordance with
right and justice.
[1913 Webster]
2. Moral rectitude; righteousness. [Obs.] --Wyclif.
[1913 Webster]
We fail of perfect rightfulness. --Sir P.
Sidney.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
rightfulness
n 1: anything in accord with principles of justice; "he feels he
is in the right"; "the rightfulness of his claim" [syn:
right, rightfulness] [ant: wrong, wrongfulness]