Dewey: Dad, what are you doing?
Hal: I am making a decision tree. It is a tool to help you make difficult decisions. First, I started out with two branches, one for pulling the plug, the other one for keeping him alive. Then I made branches from those branches for all the possible outcomes. I'm getting it all out of my head so I can see what I'm dealing with logically.
Dewey: "Pulling plug causes feeling of Godlike power. Forced to kill again"?
Hal: Well, I'm trying to cover everything. But now I have gone through all the possibilities, and I really think I am zeroing in on a decision.