Ataraxia is a noun that refers to a state of serene calmness.
Our word of the day comes directly from Greek and has maintained the same definition for centuries. Ataraxy, ending with a Y instead of an I-A is a variation of the same word.
Russ seems to have found a state of ataraxia in his life. His sense of calmness and serenity is evident to anyone who crosses his path.