thumos, is by far the most prominent of all, appearing over 750 times in Homer and the Homeric Hymns... it functions as a vibrant source of activity within the person. It proves to be a source of energetic action.
Sullivan establishes thumos as the dominant psychic entity in Homeric literature, defining it above all as a source of energetic, behavior-determining action within the individual.
, Psychological and Ethical Ideas What Early Greeks Say, 1995thesis