What do J. Robert Oppenheimer, Rachel Carson and Al Gore have in common with the priestesses at the Temple of Apollo or the prophets in the Old Testament? In this book, Lynda Walsh argues that the rhetoric of contemporary science in the public sphere preserves certain memes of prophetic ethos that can be traced back to ancient cultures. Far from living in a supposedly politically disenchanted world run by technocrats, Walsh's analysis of the way Americans treat science advisers shows many analogies with the management of political uncertainty by the Oracle at Delphi and other prophetic settings. The role of the science adviser, just like the role of the old prophets, is not so much to give a clear, straightforward answer to pressing problems, but to start an evaluative dialogue in which crises are collectively resolved. Walsh's goal is to trace those ‘persistent, recognizable cluster[s] of rhetorical strategies that [are] performed in tandem with a recurring kairos and [are] transmitted via imitation’ (p. 9, original italics), and, with it, to write a rhetorical genealogy of the prophetic ethos of contemporary science.

In Chapter 2 we are taken to Delphi to analyse the rhetorical strategies that gave this place the authority and prominence it had in Athenian political life. Walsh provides us with five traits that characterize the old prophetic consultations, traits that in later chapters she will apply to recent scientific disputes: (i) ascertainment, by which the Pythia brought about a change in the terms of the consultation, from the quest for certainty to the acknowledgement of political uncertainty and a conscious re-evaluation of the values of the petitioners; (ii) authorization, which was possible due to the oracle's ambiguity and also to the fact that the oracle was an outsider in the political debate, both geographically and in terms of expertise, and thus regarded as neutral among the contestants; (iii) confirmation of the prophet's privileged access to knowledge, which was possible only if the prophet maintained a balance between originality and predictability of her insights and signs; (iv) divination, by which petitioners and prophets were not simple receivers of divine commands but co-authors of the will of the gods by, for instance, building the possibilities among which the prophet could choose; and (v) prophecy, characterized by the answers the prophet gave in the form of riddles and puzzles, thus triggering a dialogue between oracle and petitioners and, later, forcing all actors to decide and create political settlement.

Chapters 3 and 4 take us to the seventeenth century and the rhetoric of Francis Bacon and the early Royal Society. Francis Bacon is portrayed as an ‘ethical alchemist’ who managed to alloy the tradition of the prophet with that of the early modern magician, thus shaping the characteristics of the new natural philosopher as a servant of nature, English patriot and good Christian. According to Walsh, Bacon embodies the five traits of the prophetic ethos in the following way: ascertainment is found in the progressive stages of certainty brought about by systematic actions over nature rather than passive contemplation; authorization was the basic role of the House of Solomon, later to be materialized in the Royal Society; confirmation is related to all the personal virtues of the natural philosopher as prophet and gentleman (patience, self-sacrifice, constancy etc.); divination is identified with the inductive method; and prophecy appears in the supposedly plain style of reporting which included genres such as fables and aphorisms for the outsider in order to generate more debate. In Chapter 4 the book delves into the analogy between the prophetic temples as loci outside the polis and the Royal Society as a supposedly neutral environment in the political unrest of seventeenth-century England.

After an interlude in which the author establishes an important distinction between the expert (who offers knowledge as if attainable by the majority) and the prophet (who presents knowledge as beyond the reach of the general public), the second part of the book takes us to America in the second half of the twentieth century. J. Robert Oppenheimer's self-portrayal before, during and after his trial and Rachel Carson's use of mass media are the two main examples Walsh presents of modern individual prophets: the former as a cultic prophet, an apostle for peace and a victim of political fear; the latter as an average housewife on the peripheries of academic science and political decisions creating a kairos for public debate on pesticides. More difficult to follow is the argument of Chapter 9 on the rhetorical technologies of climate change, where advocates and deniers of the importance of climate change seem to replicate prophetic patterns such as the accusation of bias in the opponents' reports or the mixture of present description and future predictions. Furthermore, since debates on climate change are still under way, this case epitomizes one of the main roles of the prophetic ethos: negotiations with uncertainty.

This book is interesting, nuanced and stimulating. At times it is difficult to see how it all works towards a consistent argument. Chapter 8, for instance, builds on the work of Karl Giberson and Mariano Artigas in their The Oracles of Science (2007) and analyses the rhetorical devices of celebrity scientists; but by so doing Walsh moves away from the main argument of the book, which is, as far as I understand, the role of scientists as prophets in the political debate and not so much as media stars. The non-American reader may at times find it difficult to relate to the dynamics of public debates presumed in this book.