(n.) The quality or state of being sound; as, the soundness of timber, of fruit, of the teeth, etc.; the soundness of reasoning or argument; soundness of faith.

admissibility advantageousness agreeableness aplomb auspiciousness authenticity authoritativeness authority balance balanced personality beneficialness benevolence benignity body calculability canonicalness canonicity class cogency common sense completeness concreteness constancy contact with reality cool cool head coolheadedness coolness credit standing density dependability desert due sense of durability entireness equilibrium eupepsia excellence expedience fairness faithworthiness fastness favorableness fine fettle fine shape fine whack fineness firmness first-rateness force fullness glowing health good condition good constitution good digestion good health good sense good shape good trim goodliness goodness gospel truth grace haleness hardness healthfulness healthiness healthy body healthy constitution healthy mind helpfulness high feather homeostasis horse sense imperturbability intactness integrity invariability invincibility justifiability justness kindness level head level-headedness levelheadedness logic logicality logicalness lucid interval lucidity marbles mass materiality mental balance mental equilibrium mental health mental hygiene mental poise merit mind mint condition nerve niceness normalcy normality normalness orthodoxicalness orthodoxism orthodoxness orthodoxy palpability picture of health plain sense plausibility pleasantness plenitude ponderability practical mind practical wisdom practicality predictability profitableness quality rationality reason reasonability reasonableness reliability religious truth rewardingness right belief right mind rightness robust health rootedness rude health rugged health sanemindedness saneness sang-froid sanity secureness security sense senses sensibleness skillfulness sober senses sober-mindedness soberness sobriety solidity solvency sound mind sound sense soundness of mind stability stable equilibrium stable state stableness staunchness steadfastness steadiness steady nerves steady state stoutness strength sturdiness substance substantiality substantialness superiority sweet reason tangibility temper the truth top shape toughness traditionalism trustworthiness undeflectability unerringness uniformity unindebtedness unshakable nerves unshakableness usefulness validity value virtue virtuousness weight wholeness wholesomeness wit worth