[toasterlovin]

I don't think you understand what I'm saying. We don't excuse murder by saying that as soon as the murderer decides to kill the victim the "fork becomes a straight line". Murder is a crime because other possible outcomes exist (the other possible outcome being that the murderer decides not to kill the victim).

And the nature of those other possible outcomes changes whether or not we consider one person killing another to be murder. Imagine that somebody puts a gun to your head and threatens to kill you unless you kill somebody else. If you decide to kill that other person, it is not considered murder because of the other possible outcome (the person putting the gun to your head kills you).

So what I am saying is that it is perfectly valid to consider forks in the road (or alternate outcomes or whatever you want to call them) when making moral arguments. We do it all the time.

(I am not saying, btw, that choosing not to have children is equivalent to murder. Murder is just a useful example for thinking through the validity of considering alternate outcomes.)