This article offers a theoretical and doctrinal solution to a vexing question in public law: how to determine the justifiability of Charter rights-limiting administrative decisions. The jurisprudence suggests three approaches, or modes of reasoning: minimal impairment analysis, ‘interest balancing’, and ‘values-advancing reasoning’. Like Cerberus, the guard dog of Hades, Canadian public law has become three-headed. While scholars and courts argue about which mode of reasoning is categorically best, the culture of justification compels us to ask instead which provides the most compelling explanation for each rights-limiting decision. Just as cutting off one of Cerberus’s heads would diminish his effectiveness as a guard dog, rejecting either of the modes of reasoning would limit decision makers’ capacity to explain their decisions and undermine a culture of justification. The article makes a theoretical case for retaining all three modes of reasoning and sets out a doctrinal approach to determining when each is applicable.