aesthetic / ascetic
Concerned with beauty versus marked by self-denial.
Aesthetic (also spelled esthetic) refers to beauty, taste, or the look of a thing: an aesthetic choice, aesthetic value. Ascetic refers to severe self-discipline, often religious: an ascetic life. A spare room can be an aesthetic decision. A spare life, chosen as discipline, is ascetic.
Examples
UseThey argued over an aesthetic point, not a moral one.
UseThe monks lived an ascetic routine.
AvoidThey argued over an ascetic point, not a moral one.