In a guest post at Superman blog Say It Backwards, my thoughts on which ego is really alter:
Superman disguises himself as Clark Kent. Right? It says it right there in the opening of the George Reeves TV series. "Disguised as Clark Kent, mild-mannered reporter for a great Metropolitan newspaper." Kent is the mask, and Superman is the identity.
Or is he?
Read the full post, which delves a bit into Batman, Alan Moore, and Jesus, here.