Lyric discussion by Fantasticfolk 

Cover art for Baby In Two lyrics by Pernice Brothers

I think this song is about being in a long term relationship with someone who is also in love with someone else.
He wishes he didn't know, but he does know subconsciously, and he wishes he could let this person go, but he can't because of love.

He knows that he is holding onto nothing, and that the relationship will end soon (e.g., sometimes this sweet life feels like it's never been as bad as it is tomorrow), but he feels that this person must be the one to decide to end it because he can't.

He wishes he could find a sure and simple way to reach this person, to force them to make a decision between him and the other person they are in love with, or simply to make a decision to let him go (i.e., like the Biblical reference Enid mentioned, where like King Solomon suggested cutting a baby in two when two women came fighting over who's baby it really was, forcing the true mother to reveal her identity by thinking of the best interest of the baby and letting the baby go).