Sophrosyne
Sophrosyne (Greek: σωφροσύνη) is an ancient Greek concept of an ideal of excellence of character and soundness of mind, which when combined in one well-balanced individual leads to other qualities, such as temperance, moderation, prudence, purity, decorum and self-control. In other languages there is no equivalent word.
I was introduced to this term today by the Calm meditation app and it resonated with me as it is how I have been trying to live my life. I don’t know if I always succeed but by working on my own mental health and soundness of mind, it has really improved other areas of my live.