THE LIFE AND DEATH OF SEXUAL DIFFERENCE Becoming Undone: Darwinian Reflections on Life, Politics, and Art by Elizabeth Grosz. Durham, NC: Duke University Press, 2011. Pp. 264. $84.95 cloth; $23.95 paper.In Becoming Undone, Elizabeth Grosz connects Charles account of biological evolution as an unpredictable and open-ended process of variation to the philosophies of Henri Bergson, Gilles Deleu ze, and Luce Irigaray in order to elaborate a more or less neomaterialist ontology of sexual difference as the engine of natural existence, the mechanism productive of the complexity and excesses of life as we may or may not know it. The book is set over and against what Grosz perceives as a postmodern feminism in which notions of nature and matter have been sidelined, and where, more precisely, ontological inquiries into the constitution of life have been subsumed under epistemological considerations of how bodies come to matter exclusively in terms of language, discourse, and culture. Grosz, in contrast, develops a Darwinian feminism and a postmodern Darwinism that attempts to rethink the materiality of sexual difference through the inhuman time of evolutionary becoming.Whereas feminist theorists have generally been reluctant to engage with Darwinian thought beyond the scope of epistemological critique, Grosz's work takes a different and more affirmative approach. The aim of Becoming Undone is not to address the androcentrism apparent in theory of evolution, nor to assess the essentialist approaches to sexual and racial differences within neo-Darwinian sociobiology or evolutionary psychology, but rather to take hold of what in work is useful for the elaboration of feminist thought beyond postmodern theories of power and difference, and past the limits of egalitarian politics of recognition. Against this background, Grosz advances a philosophy of life and matter as deeply attuned not only to each other but to the generative force of duration-the becoming and unbecoming- through which biological evolution proceeds as an open-ended process of differentiation, especially sexual differentiation.Starting from the basic Darwinian insight that the differences between humans and other animal species, as well as among human beings, are differences in degree and not in kind, Grosz uses the philosophies of Bergson and Deleuze to theorize evolutionary emergence not merely as a relation between different forms of life but as a dynamic entanglement between life and the inorganic forces of matter. Life and matter are conceptualized not as binary opposites but as divergent tendencies or trajectories, two different degrees of the same, ever-differing, force of duration: the temporal or evolutionary impulse that enables life to actualize the vital indeterminacy (34) of the material world from which it emerges, to unfold the dynamic unpredictability that is folded into matter as the potential to become different. This nonteleological reading of Darwin is directly opposed to the traditions of social Darwinism that tend to reduce all evolutionary mechanisms to the teleological principle of survival-a reduction that has on more than one occasion facilitated a classification of humanity as the pinnacle of creation that runs counter to own work. Indeed, Grosz posits a fundamental continuity between individuals and species of all kinds, not because they share a common genealogy, but because all of life is enjoined in the transformation of matter. Grosz's Darwinism, then, is a highly Deleuzian one in which evolution is construed as a transversal force of creative transformation, an impersonal cut across the boundaries between organic and inorganic vitality, an unpredictable and increasingly complex elaboration of life as the power to differ.If, as Deleuze has suggested, Darwin's great novelty was that of inaugurating the thought of individual difference,1 Grosz seizes upon idea that it is sexual difference, in the form of sexual selection, through which life first elaborates itself as a continuous process of variation and creative excess. …