The Collaborative International Dictionary of English v.0.48:

Impartiality \Im*par`ti*al"i*ty\, n. [Cf. F. impartialit['e].]
   The quality of being impartial; freedom from bias or
   favoritism; disinterestedness; equitableness; fairness; as,
   impartiality of judgment, of treatment, etc.
   [1913 Webster]

         Impartiality strips the mind of prejudice and passion.
                                                  --South.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impartiality
    n 1: an inclination to weigh both views or opinions equally
         [syn: impartiality, nonpartisanship] [ant:
         partiality, partisanship]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "impartiality":
   Olympian detachment, abnegation, abstention, abstinence,
   anythingarianism, calm, calmness, conservatism, constraint,
   continence, control, cool, cop-out, detachment, disinterest,
   disinterestedness, dispassion, dispassionateness, equitability,
   evasion, evenhandedness, evenness, fairness, fence-sitting,
   gentleness, golden mean, happy medium, independence, indifference,
   judiciousness, juste-milieu, justness, lenity, loftiness,
   meden agan, middle way, mildness, moderateness, moderation,
   moderationism, mugwumpery, mugwumpism, neutralism, neutrality,
   nonalignment, noncommitment, noninvolvement, nonpartisanism,
   nonviolence, nothing in excess, nothingarianism, objectivity,
   pacifism, prudence, repose, restraint, self-abnegation,
   self-control, self-denial, self-restraint, selflessness, serenity,
   sobriety, stability, steadiness, strict neutrality, temperance,
   temperateness, tranquillity, unbias, unbiasedness, unexcessiveness,
   unextravagance, unextremeness, unopinionatedness, unprejudicedness,
   unselfishness, via media