Fuller writes of Austin: ‘Over and over again he teeters on the edge of an abandonment of the command theory… Yet he never takes the plunge. He does not take it because he had a sure insight that it would forfeit the black-and-white distinction between law and morality that was the whole object of his Lectures…’ (Lon L. Fuller, “Positivism and Fidelity to Law – A Reply to Professor Hart” (1958) 71 Harv. L. Rev. 630, p 640). Does this comment identify a weakness in legal positivism generally?