Carl Jung on Hostile Brothers. Lexicon
An archetypal motif associated with the opposites constellated in a conflict situation. Examples of the hostile br0thers motif in mythology are the struggle between Gilgamesh and Enkidu in The Gilgamesh Epic, and the Biblical story of Cain and Abel. Psychologically, it is generally interpreted in terms of the tug of war between ego and shadow.
http://www.nyaap.org/jung-lexicon/h/
