Legal argument inside liberal practice is aware of two perils that might defeat rational resolution in law. The perils are conditions of disorder that exist beyond law. Language outside law is pervasively vague. Morality outside law is divided by disagreement. The peril for law is that disabling disorder seen to exist outside law may break out within law. Peril posited to exist by liberal law might conceivably be overcome. Two legal philosophers, H. L. A. Hart and Ronald Dworkin, show what it would mean to overcome peril. Each says that a mode of legal argument ‒ formal argument for Hart, ideal argument for Dworkin ‒ is able, for the most part, to avoid disorder and so succeed in achieving rational resolution. Each theorist thinks that the mode of argument affirmed by the other often fails ‒ but each thinks that one mode succeeds, and so law as a whole does. Critical scholars Roberto Unger and Duncan Kennedy put forward deeply skeptical ideas of disorder which, applied to law, would cause law to fail irremediably. But these deeply skeptical views about morality and language, unlike the two premises accepted by Hart and Dworkin, are not embraced in doing of law.