Newton's Flaming Limp Laser Sword

A philosophical postulate that states, "That which cannot be proven or disproven should probably not be argued about, but let's do it anyway to get some needed blood pumping."

Jenny: So if you could travel back in time, would you kill your grandfather?
Keenan: I invoke Newton's Flaming Limp Laser Sword!
Jenny: So? I totally would.
Keenan: Hell no!