Closed Material Procedures are widely considered to be unjust. In his influential A Theory of Justice, Rawls sets out that trials must be fair and open, and that such precepts of natural justice ensure the impartiality of the legal order. I argue that whilst this commits Rawls to a rejection of the permissibility of CMPs, he is not right to do so, and his theory does not require him to do so. Firstly, the conception of natural justice upon which Rawls (...) bases his view of open justice is not so strict as to demand this so long as the legal system ensures a sufficient gist of the closed material is provided. Secondly, it is plausible that individuals in Rawls’ original position, would select CMPs due to the role security and stability play in a just state, the importance of which Rawls explicitly recognises. I conclude that CMPs are consistent with Rawls’ theory of justice, despite his assertions in A Theory of Justice. Given the importance and influence of Rawls’ theory, this is an important step in demonstrating the permissibility of such procedures, duly circumscribed. (shrink)