One plank, two drowning sailors — Carneades asked who may live
Two shipwrecked men reach the same plank, but it holds only one. Carneades argued that the one who pushes the other off to save himself may be blameless — not because it's just, but because self-preservation can override justice when everything is at stake. Cicero preserved the case as the sharpest ancient test of where morality actually gives way.