c. 1300, qualite, "temperament, character, disposition," from Old French calite, qualite "quality, nature, characteristic" (12c., Modern French qualité), from Latin qualitatem (nominative qualitas) "a quality, property; nature, state, condition" (said [Tucker, etc.] to have been coined by Cicero to translate Greek poiotēs), from qualis "what kind of a" (from PIE root *kwo-, stem of relative and interrogative pronouns).
In early use, and for long thereafter, with awareness of the word's use in Aristotelian philosophy. From late 14c. as "an inherent attribute," also "degree of goodness or excellence." Meaning "social rank, position" is c. 1400, hence "nobility, gentry." From 1580s as "a distinguished and characteristic excellence."
Noun phrase quality time "time spent giving undivided attention to another person to build a relationship" is recorded by 1977. Quality of life "degree to which a person is healthy and able to participate in or enjoy life events" is from 1943. Quality control "maintenance of desired quality in a manufactured product" is attested from 1935.
early 15c., "natural character, quality of being natural, normality," from French naturalité, from Late Latin naturalitatem (nominative naturalitas), from Latin naturalis (see natural (adj.)). Meaning "natural feeling or conduct" is from 1620s.