Harry’s following Voldemort to what seems to be his doom.
Suppose, said that last remaining part, suppose we try to condition on the fact that we win this, or at least get out of this alive. If someone told you as a fact that you had survived, or even won, somehow made everything turn out okay, what would you think had happened—
Not legitimate procedure, whispered Ravenclaw, the universe doesn’t work like that, we’re just going to die
I never understood why this was considered illegitimate. If we have a particular desired outcome, it makes sense to me to envisage it and work backwards from there. Remaining open to deviations of course.
I haven’t read HP:MoR, so don’t know exactly what is happening in the example, but might you not have doubt about whether the supposition is false or not? Envisaging a solution is a way of interrogating the structure of the problem, including whether it is solvable at all. Sure though, if you want to use the suppostion to prove something else, rather than work backwards from it, you want to be sure of the supposition in the first place.
I’m out of my depth with mathematical and logical proofs, but wouldn’t this be just rhetorical engagement with a hypothetical. In probability theory we can use conditionals, this feels like doing that.
I’m reminded of this part from HP:MoR when
Harry’s following Voldemort to what seems to be his doom.
I never understood why this was considered illegitimate. If we have a particular desired outcome, it makes sense to me to envisage it and work backwards from there. Remaining open to deviations of course.
If you use the “suppose …” feature in a proof, you need to make sure the supposition isn’t false in context of the proof
I haven’t read HP:MoR, so don’t know exactly what is happening in the example, but might you not have doubt about whether the supposition is false or not? Envisaging a solution is a way of interrogating the structure of the problem, including whether it is solvable at all. Sure though, if you want to use the suppostion to prove something else, rather than work backwards from it, you want to be sure of the supposition in the first place.
I’m out of my depth with mathematical and logical proofs, but wouldn’t this be just rhetorical engagement with a hypothetical. In probability theory we can use conditionals, this feels like doing that.