The Rachel Divide, a documentary about Rachel Dolezal and the controversy over her claims to racial identity, came out in April on Netflix. For readers who don't remember the story, Rachel Dolezal was the president of the Spokane chapter of the NAACP. She was forced to resign after her parents revealed that she was Caucasian. Her critics charged her with lying about having been the victim of hate crimes, with cultural and racial appropriation, with taking advantage of white privilege, with using her black sons, and with violating the rules of government ethics in her service on official bodies as a racial activist.

Dolezal defended herself as black, despite her biological parentage. For her, racial identity runs deep: it is how you feel, think, act, and live. As the documentary reveals, however, her view is not a simplistic form of subjectivism such as "what I think I am is what I am." Rather, it is that if one lives as black, physically, psychologically, socially, and in any other relevant respect, one is black. This she claims to have done and so on her view she was—and still is—black. She has reportedly changed her name legally to Nkechi Amare Diallo to reflect this identity.

But what if race just doesn't exist at all, or isn't related to identity in the way assumed in the Dolezal documentary? In a recent and excellent book, Rethinking Race, Michael O. Hardimon offers some help in thinking about the metaphysics of race. Hardimon distinguishes four concepts of "race": racialist race, minimalist race, populationist race, and socialrace. "Racialist race" is the pernicious idea that races can be distinguished by intrinsic biological essences, with associated characteristics such as intelligence that allows ranking as superior and inferior. "Minimalist race" is the stripped-down idea that races are distinguished by patterns of visible physical features such as skin color that correspond to differences in geographical ancestry. "Populationist race" is a scientific concept that characterizes races as groups of populations belonging to biological lines of descent that can be traced back geographically. Finally, "socialrace" (closed compound) is the critical concept of social groups that are taken to be racialist races and assigned to social positions specified by racist norms.

Hardimon argues for eliminativism with respect to racialist race. That is, he contends that there is no such thing as racialist race. At the core of his argument is the evidence from genetic science about variation that undermines claims to biological natural kinds. Eliminativists are mistaken, however, if they draw the conclusion that there is nothing to the concept of race at all and that we should simply stop using it. For racialist race is not the same as "race"; eliminativism about racialist race does not entail eliminativism about minimalist race, populationist race, or socialrace.

So what concepts of race figure in the Dolezal controversy? The most likely candidates are either racialist race or socialrace. In claiming to be "black," Dolezal was not claiming only to have biological features that correspond to ancestry differences, although she did assume the appearance of blackness. Nor was she claiming to have a place in a scientific account of population ancestry. Most likely, she was claiming a place in an oppressed social group—that is, claiming socialrace—in which case her critics would be right to point out that she had not grown up in such oppressed circumstances, at least with respect to race—although the evidence suggests that she grew up under conditions of oppression stemming from abuse. (The importance of Dolezal's status as abuse victim is underexplored in the documentary). On the other hand, her statements in the documentary seem to say that in virtue of living as black for a number of years, she had become racially oppressed. Nevertheless, critics in the documentary who saw her as asserting race privilege averred that she could always go back to living white, a change she would see as impossible in light of her lived identity.

But on Hardimon's view, racialist race lurks within socialrace. Indeed, racialist race seems to surface at some points in The Rachel Divide. Here's how. Racialist race justifies the social positions assigned to certain social groups. Since racialist race does not exist, however, the justification is illusory. This does not mean that socialrace is illusory but that it is a social phenomenon rooted in a view of something that does not exist, racialist race. Some of Dolezal's critics in the movie seem committed at least to the essentialist view that she has tried to take on characteristics of the wrong kind for her. Conversely, she at times flirts with essentialism, suggesting that she is a kind of being, a being that is of a disfavored race, in a sense beyond being oppressed by others who adopt the racialist concept of race and apply the label "black" to her.

Much of the movie consists of interviews with Dolezal and her critics. The portrait of her that it presents is mixed and invites viewers either to side with her or against her, as its multiple critics have done. The movie would have benefited, however, from some philosophical consideration of what race is—or is not—and what claims to racial identity assert.