Clough is perhaps best known now for his short poems "Say Not the Struggle Naught Availeth", a rousing call invoking military metaphors to keep up the good fight (which fight is unspecified, but it was written in the wake of the defeat of Chartism in 1848), "Through a Glass Darkly", an exploration of religious faith and doubt, and "The Latest Decalogue", a satirical take on the Ten Commandments. "The Latest Decalogue's" couplet on murder, "Thou shalt not kill; but needst not strive officiously to keep alive:" is often quoted – usually out of context – in debates on medical ethics in the sense that it is not right to struggle to keep terminally ill people alive, especially if they are suffering. Further, this couplet influenced Isaac Asimov's Three Laws of Robotics (in particular, the First Law's "or through inaction" clause).