In late August 2009, Caster Semenya, an astonishingly muscular South African runner, won the women's 800-meter race at the World Track and Field Championships held in Berlin. Yet before Semenya could celebrate, the general secretary of the International Association of Athletic Federations took the rostrum and announced that Semenya would undergo gender testing to determine whether she is female. If the tests ruled that Semenya was indeed a male, it was announced, she would be stripped of her medals.

Cases such as Semenya's, which push mainstream understandings of identity, are the subject of Georgia Warnke's book After Identity: Rethinking Race, Sex and Gender. In presenting similarly anomalous cases of gender ambiguity, Warnke directs us to ponder the nature of identity and the legitimizing sense of biological certainty we attach to some and not other forms of identity. In the first chapter, Warnke presents the case of a set of male twins, one of whom loses his penis to a botched circumcision. The child's distraught parents are told by a renowned surgeon that it is possible to raise the child as female given the biological impossibility of him being able to live as a male without a penis, and they are advised that they should pursue castration, hormone therapy, and raise him as female. The resulting experiment involves one of the twin boys being raised as Brenda instead of Bruce, as she was born. Despite aggressive acculturation as a female, the wearing of dresses, the buying of dolls, and the incessant promotion of all behaviors female, Brenda is notably a tomboy. When told at adolescence about the decision, she is furious, abandons all hormone therapy and remaining surgical regimens, gets a double mastectomy, and chooses to live as a man, David Reimer. She marries a woman and continues life as a man but then, following a divorce, commits suicide.

David Reimer's story is accompanied by numerous other accounts of both medical mistake and medical conditions that test the belief that there is some essential biological basis to gender that invests this form of identity with a more concrete foundation than other forms of identity. Warnke considers in turn a number of purportedly unarguable foundations for gender identity claims. One of these, chromosomal identity, is thrown into question when she discusses a condition called AIS or Androgen Insensitivity Syndrome. Individuals with AIS have XY chromosomes, yet are are unable to process testosterone, giving them the physical appearance of women with large breasts and extraordinarily beautiful skin. Does this make them men or women, asks Warnke? What happens in cases where biological females living as men in homosexual relationships choose to have babies with their partners?

While building her thesis, Warnke admits that such anomalies are compelling for their occurrence rather than their frequency. Her point is that their variation from the norm forces us to question those aspects of gender identity that were previously considered unassailable because of their assumed biological reality. In her chapter on race, Warnke attacks this very unassailability by harkening back to arguments that similarly treated race as a concept that was based on biology with little room for ambiguity. Most convincing in this regard is her discussion regarding the lengths to which authorities were willing and able to go to prevent miscegenation. Just as chromosomal identity is now being relied on as a basis of certainty to discern gender identity in courts around the country (with varying results), quantities of African American blood were similarly relied on to consider questions of inheritance in cases where the racial purity of one of the partners was questioned.

Racial identities, however, changed. When the Irish first arrived in the United States in the 1840s, Warnke notes, American Anglo-Saxons defined the new “race” of immigrants in terms of their “dark skin, big hands and feet, broad teeth and pug noses. The Irish were [considered] pot-bellied, bow legged and abortively featured especially remarkable for open, projecting mouths with prominent teeth and exposed gums, their advancing cheekbones and depressed noses bearing barbarism on the very front” (p. 79). Warnke notes the trajectory of how Irish identities changed, moving from racial to ethnic and finally to recreational identity, where ascription becomes optional and often limited to holidays celebrated or certain foods enjoyed. Attentive to historical and power dimensions, she is careful to note that the distinctive Irish trajectory is not a predictive path for all racial identities; indeed, racial identities such as African American and Asian American have not and possibly may not undergo a similar denouement.

The crux of Warnke's argument emerges in chapter 3, aptly titled “Race and Interpretation.” Here, Warnke brings together the descriptive accounts presented earlier to argue that racial identity has more in common with textual interpretation than has been heretofore acknowledged. Both textual hermeneutics and evaluations of multidimensional aspects of identity are ways of understanding “who and what we and others are” (p. 118). Giving examples from a variety of texts, Warnke argues that the complex interplay of individual and collective histories, contextual factors, and existing norms all combine to shape encounters with a text. As readers of texts, we do not deny the validity of one interpretation over another, but we are able to accept and even expect variety in our textual encounters. According to Warnke, the theoretical consequence is that we recognize “the limits of our understanding” (p. xx) and allow for the possibilities of new understandings and relations that we may not previously have considered.

This, then, is Warnke's project: to dislocate existing arguments that see some forms of identity as malleable and open to variety while treating others as concrete and static, and to focus on understanding individuals with the same nuance and complexity that we invest in texts. The most provocative portion of her theory is its application not simply to race—whose variegated terrain has been analyzed before—but to gender, which is often considered far from open to this interpretative approach. In doing so, Warnke is explicit in recognizing differences between forms of identity; the fact that as identities, both race and gender are amenable to textually inspired interpretation does not in turn mean that they are the same. Indeed, as she says, “individuals do not come to think they were born in the wrong racial or ethnic body” (p. 172).

The most exemplary theoretical work takes ordinary concepts and reimagines them in ways that expose both their possibilities and their limitations. In her explications on gender, sex, and race, Warnke is able to do just that. The final chapters of her book extend her interpretive analyses of anomalies of gender, sex, and race, and apply them to existing controversies. Current laws such as the military's “Don't Ask, Don't Tell”—which refuse to recognize the ambiguity of sex and gender—are thus likened to nineteenth-century miscegenation laws that were similarly limited by constricted conceptions of race. And in the same way that we now regard anti-miscegenation laws as fundamentally unjust, we ought to regard their twenty-first-century counterparts as equally unjust. Thus applied, Warnke's argument represents a valuable contribution to a growing genre of “non-ideal” political theory that engages with social facts and public controversies and normatively expands concepts to meet the demands of deliberation in the public sphere. By unearthing the ambiguities within concepts of race, sex, and gender, Warnke coaxes even the most reluctant readers to reconsider and revise their assumptions about both identity and the ways that identity ought to be processed by the laws, policies, and processes of a democratic society.