 Pure jurisprudence guides ethics in constructing a theory of humanity by overcoming a problem that, Cohen thinks, any theory of humanity faces. He claims the concept of humanity has a tension contained in it: a human being is at once an individual and a member of various pluralities, such as religious communities or economic collectives (Cohen 1902, 3ff). Further, the wills of pluralities of individuals do not necessarily cohere: individuals do not necessarily will things that are consistent with what other individuals will, or with what the community as a whole wills. But, Cohen suggests, without an account of what an individual may will consistently with the wills of others, we have no coherent account of the moral agent as both an individual and a member of a plurality. Thus any theory of humanity requires an account of how to reconcile individuals’ wills within a plurality. As Cohen puts it, individuals’ wills must be unified into a totality. Or, in somewhat less opaque language, we must understand how the universal laws of an ideal state can reconcile the wills of individuals and pluralities (Wiedebach 1997, Pt. 3). Further, according to Cohen, if we want to think systematically about what those universal laws are, we must start by reflecting on the evolving body of legal doctrine provided by pure jurisprudence—the science of universal laws. For Cohen, the doctrines of pure jurisprudence to do evolve arbitrarily: they evolve in an unending process of demanding and giving reasons. Paul Nahme thus claims that “[w]e can therefore describe Cohen’s account of the ethical will as a logic of public reasoning...”(Nahme 2019, 268).