As the 1990s drew to a close it became just a question of time. For almost two decades, in sf, advertising, popular and academic journals, corporate portfolios, funding applications, etc., the virtual has been hyped at the expense of embodied existence. There have always been voices of dissent: William Gibson's Neuromancer (1984), which some might consider the root of it all, concludes with a rejection of the ``bodiless exultation of cyberspace'' in favor of dropping back into the ``meat'' of the body; and many - feminists, people of color, and other Others - have found inspiration in the radical revision of the cyborg outlined in Donna Haraway's 1985 manifesto, insisting on the realities of living in bodies, of being particular bodies, marked, positioned, scarred, distorted and deformed by the operations of gender, race, and class. But until now there has not been a comprehensive rebuttal.

Hayles is a professor of English who also holds degrees in chemistry. Her first book, The Cosmic Web: Scientific Field Models and Literary Strategies in the Twentieth Century (1984), complexly interrelated the concept of the field found in various scientific models ranging from quantum mechanics to Saussure's linguistics with fiction by Robert Pirsig, D. H. Lawrence, Vladimir Nabokov, Jorge Luis Borges and Thomas Pynchon. Interdisciplinary work of the highest order, it hinted at an ethical and political vision of holistic interconnection which her remarkable Chaos Bound: Orderly Disorder in Contemporary Literature and Science (1990) expanded upon. An astute introduction to non-linear dynamics, a provocative exploration of post-structuralist literary and cultural theory, and a thrilling exposition of texts by Henry Adams, Stanislaw Lem, and Doris Lessing, it uncovered the shared cultural matrix from which contemporary critical theory and chaos science emerge. The introduction to her edited collection Chaos and Order: Complex Dynamics in Literature and Science (1991) develops her critique of Western culture's order/disorder dichotomy, insisting upon the importance of the equivocal and the ambiguous in the face of the totalizing ambitions of scientific and mathematical language. Her new book takes this a stage further.

How We Became Posthuman is structured around three interwoven histories: how informa\-tion ``came to be conceptualized as an entity sepa\-rate from the material forms in which it is thought to be embedded''; how ``the cyborg was created as a technological artifact and cultural icon''; and ``how a historically specific construction called the human is giving way to a different construction called the posthuman'' (p. 2). Having mapped the seriated development of cybernetics - the dominant notion of homeostasis was transformed into a preoccupation with reflexivity, which in turn was superseded by virtuality - Hayles examines the work of prominent thinkers from each stage, recovering the contemporary debates from which they emerged. For example, she contrasts Claude Shannon's definition of information as a ``probability function with no dimensions, no materiality, and no necessary connection with meaning'' with Donald MacKay's alternative that ``linked information with change in a receiver's mindset and thus with meaning'': the transcripts of the Macy Conferences indicate that the selection of Shannon's definition ``was driven by the twin engines of reliable quantification and theoretical generality'' (p. 18). By revisiting this decision-making process, and charting its consequences, Hayles emphasizes the contingency of an historical juncture which has come to have seemed inevitable. As reflexivity replaced homeostasis and …