R (Evans) v Attorney General [2015] UKSC 21; [2015] 2 W.L.R. 813 is a case of real constitutional interest and importance. The division of opinion within the Supreme Court reflects divergent conceptions of fundamental principle. While all the Justices affirmed the principles of parliamentary sovereignty and the rule of law, they understood them differently, resulting in disagreement about their correct reconciliation on the facts of the case. The majority of Justices achieved a real integration of these basic principles in a manner that the dissentients’ superficially more straightforward approach did not.