Lyric discussion by griffer 

Cover art for Half Jack lyrics by Dresden Dolls, The

Too much literalism in these commentaries.

I think 'Half Jack' works at several levels- the archtypal rejection of the father as metaphor for rejection of the elements of your persona that you are ashamed. Personifying and assigning a sexual role to negative aspects of personality- anger, aggression- is a very old and powerful image. It is the image of demon posession- the evil from without becomes within. It is the sins of the father visited on the son.

Consider, if the mother figure is nurturing and loving than what is the opporite, and if male is the opposite of female....

The act of rejection and abandonment- behaviors of the 'deadbeat dad' because men can leave, mothers can't, or can they? How would an abondoned child raised by an imperfect mother look on their own misdeeds- their own dark side? From the extreme to the mundane- from betraying a lover to aborting a child, any act that the person finds unseemly, despicable, could be blamed on 'bad blood'. But what a psychosis to create the poisoned, tainted entitiy inside yourself! Who wouldn't want to excise that both literally and figuratively. A full house indeed.

Excuse the spelling goofs, typing very fast, too lazy to spell check.