A growing body of literature has emphasised the role of equity as a body of second order principles. These scholars argue that what makes equity distinct is that it assumes a particular outcome at common law, but then controls or disables one party's insistence on her legal entitlements. Where do equitable bars to relief fit within such accounts? This article argues that equitable bars to relief fit comfortably with the view that equity is second order law. This is for a simple reason: equity prevents the unjust exercise of legal entitlements. However, equitable rules are also amenable to being exercised unjustly. To prevent equitable rules being abused, equitable doctrines require some limited discretion to be built in. If this were not the case, then the general law would require a third set of rules to control equity and then a fourth set of rules to control those rules (ad infinitum).