This paper attempts to identify a principle of equal treatment that gives specific structure to our widely shared judgments about the circumstances in which we have moral reason to object to the differential adverse treatment of others. I formulate what I call a “substantive” principle of equal treatment (to be distinguished from principles of formal equality) that describes a moral constraint on the reasons we can have for picking out individuals for differentially adverse action. I argue that this constraint is violated when an action, in view of its rationale, expresses lesser respect for the moral status of an individual under some differentiating description, compared to the respect reserved to another class of individuals who are not picked out by that description. I show that this substantive demand of equal treatment is not morally otiose and reveal the fallacy underlying accounts that have concluded otherwise.
15 LEGAL THEORY 149 (2009)