Source : Webster's Revised Unabridged Dictionary (1913)

Disinterestedness \Dis*in"ter*est*ed*ness\, n.
   The state or quality of being disinterested; impartiality.

         That perfect disinterestedness and self-devotion of
         which man seems to be incapable, but which is sometimes
         found in woman.                          --Macaulay.

Source : WordNet®

disinterestedness
     n : freedom from bias or selfish motives