The Collaborative International Dictionary of English v.0.48:

Judiciousness \Ju*di"cious*ness\, n.
   The quality or state of being judicious; sagacity; sound
   judgment.
   [1913 Webster]

WordNet (r) 3.0 (2006):

judiciousness
    n 1: good judgment [ant: indiscreetness, injudiciousness]
    2: the trait of forming opinions by distinguishing and
       evaluating [syn: judiciousness, sagacity,
       sagaciousness]

Moby Thesaurus II by Grady Ward, 1.0:

125 Moby Thesaurus words for "judiciousness":
   abnegation, abstinence, appreciation, appreciation of differences,
   appreciativeness, artistic judgment, calculation, calm, calmness,
   canniness, care, careful consideration, carefulness, caution,
   cautiousness, circumspection, circumspectness, connoisseurship,
   conservatism, consideration, constraint, continence, control, cool,
   cool judgment, critical niceness, criticalness, deliberate stages,
   deliberateness, deliberation, delicacy, discreetness, discretion,
   discriminating taste, discriminatingness, discrimination,
   discriminativeness, dispassion, evenness, fastidiousness, feel,
   feeling, fine palate, finesse, gentleness, gingerliness,
   golden mean, good judgment, guardedness, happy medium, hedge,
   hedging, heed, heedfulness, hesitation, impartiality, judgment,
   juste-milieu, lenity, making distinctions, meden agan, middle way,
   mildness, mindfulness, moderateness, moderation, moderationism,
   neutrality, niceness of distinction, nicety, nonviolence,
   nothing in excess, pacifism, palate, pawkiness, policy, polity,
   prior consultation, providence, prudence, prudentialism,
   prudentialness, refined discrimination, refined palate, refinement,
   reflection, reflectiveness, regardfulness, repose, restraint,
   safeness, safety first, selectiveness, self-abnegation,
   self-control, self-denial, self-restraint, sense, sensibility,
   sensitivity, serenity, slowness to act, sobriety, solicitude,
   sound judgment, soundness of judgment, stability, steadiness,
   subtlety, tact, tactfulness, taste, temperance, temperateness,
   tentativeness, thoroughness, thoughtfulness, tranquillity,
   uncommunicativeness, unexcessiveness, unextravagance,
   unextremeness, unprecipitateness, via media, weighing