Stefani Engelstein. Sibling Action: The Genealogical Structure of Modernity. New York: Columbia University Press, 2017. 360 pp. ISBN 9780231180405 S tefani Engelstein’s book documenting how sibling relationships were constitutive of many disciplines that emerged in the late eighteenth and early nineteenth centuries— including anthropology, economics, linguistics, comparative literature, and evolutionary biology—reveals the author’s own deep reflections on and detailed study of a number of seemingly disparate fields of knowledge. This fascinating volume demonstrates how a common method of genealogical organization, with increased emphasis on sibling as opposed to parent-child relationships, structured scientific, social scientific, and humanistic discourses during this period. Genealogical trees showing the descent of biological species, of languages, and of human beings from a common ancestor or set of ancestors often high- lighted what Engelstein calls “horizontal” relationships, those among multiple descendants of an ancestor or set of ancestors. For example, diagrams made by nineteenth-century lin- guists show modern language groups like Germanic, Celtic, and Slavic as “siblings” descended from a common Indo-European “ancestral” language. To be sure, the genea- logical model is an over-simplification that does not allow for later influences of “sibling” languages, species, races, or religions upon each other after they have separated from the common ancestor, and Engelstein does address the explanatory weaknesses as well as the strengths of the genealogical paradigm. Her argument about the prevalence of this model across various disciplines is convincing and well supported by evidence from a variety of fields. A point of departure for Engelstein is Sophocles’s Antigone, and its reception from the eighteenth century through the early twentieth century. Antigone is certainly a play that prioritizes sibling relationships, but also one that complicates the distinction between sib- ling and parent, since Oedipus is both father and brother to the heroine while Creon, her antagonist and uncle, is also a quasi-sibling or brother-in-law, as the brother of Jocasta, Antigone’s mother and Oedipus’s mother/wife. The play provides a heightened example of Engelstein’s theory that the relationship with a sibling, as not-quite-self but not-quite- other, is crucial to the notion of subjectivity that emerged in the late eighteenth century. The challenges that the play presents to the definition of the sibling fit with Engelstein’s idea that sibling relationships are dynamic and multiple, expanding the possibilities for personal and political alliances. Although the book’s title alludes to “siblings,” a generic term, Engelstein does dif- ferentiate among brother-sister, brother-brother, and sister-sister relationships. The second section of the book, on “Fraternity and Revolution” illustrates the cost of political “fraternit  e” from which the sister is excluded. In fact, Engelstein offers a nuanced argu- ment that the sister, while not recognized within the emerging political paradigm, nonethe- less serves a key function as “catalyst,” in that love between brother and sister provides an ideal model for the egalitarian relationships among (male) citizens that emerge from the French Revolution. At the same time, the sister reveals unspoken problems in the new pol- itical structure, including the problem of political and sexual consent, when she functions as the (often unacknowledged) erotic object underpinning men’s commitment to politics, a realm that invokes passion yet demands the exclusion of the explicitly erotic. Engelstein traces the ways in which eroticism both provides the foundation and is in theory excluded 258 THE GERMANIC REVIEW ♦ VOLUME 94, NUMBER 3 / 2019