While Thomas Wiedemann (G&R 40.1 (1993) 48–57) demonstrated thirty years ago that Sallust's digressions have tight thematic links to the narratives of his monographs, Edwin Shaw has now gone further, claiming that those digressions are where Sallust's historiographical vision is most evident. According to S., Sallust uses the digressions, which reach beyond the chronological confines of his texts’ subjects, to develop his interpretation of Roman history on a grander scale. In so doing, Sallust expands the intellectual possibilities of historiography by engaging with other modes of inquiry. S.'s Sallust is a wide-ranging intellectual actively participating in cultural debates centering on Roman identity at a time of extreme political and social turmoil. Far from being the resentful senatorial reject who grinds his axe in literary form, this Sallust is a detached historian and an innovator in Roman historiography whose work bears closer resemblance to Cicero's philosophical works, Varro's De Lingua Latina and juristic writing than had previous Roman historiography. Indeed, Sallust's incorporation of geography, etymology and myth reveals a project of generic enrichment which even bears a resemblance to the early poetry of Vergil and Horace.

S. makes three major arguments across the book's introduction and five chapters. First, he asserts that digressions are ‘central loci of the historian's articulation of the ideas developed in his historiography’ (425). One reason for their significance, he argues, is that they clearly reflect the oratorical practice of dispositio, the speaker's purposeful ordering of material for a compelling speech. This useful emphasis on dispositio allows S. to work with the rhetorical nature of Sallust's historiography without conceding a primary focus on historical truth. Second, S. claims that the digressions are key to understanding Sallust's analysis of Roman history. They illustrate the supposed terminal decline which Sallust outlines on three levels, the highest of which is the theory of translatio imperii. S. sees the inexorable shift of power from the weaker to the stronger as the crucial insight of the archaeology in the Bellum Catilinae instead of the disappearance of metus hostilis –– which, he notes (as others have) is not explicitly articulated until the Bellum Iugurthinum. S. identifies the next level of Sallust's analysis of Rome's first-century b.c. crisis as the malum publicum of factional strife, based on a Thucydidean model (3.82–4) but with crucial variation. Unlike Corcyrean politics, which came apart under external threat, Roman politics maintained an uneasy equilibrium so long as there was pressure from outside; it was the absence of external threat that resulted in destabilising ambition, greed, and factional strife. The lowest level of Sallust's analysis of Rome's supposed decline is individual psychology. S. shows that Sallust's moralising about individual vice is the final manifestation of much larger processes of decline. The third argument of the book locates Sallust within the intellectual milieu of his time, and demonstrates the rich, creative period in literature when authors were sharing their work in artistic circles.

The introduction places Sallust in a context of intellectual experimentation as a historiographical innovator. The first chapter defines digressions and applies the concept of dispositio to them. Ch. 2 interprets the archaeology (Cat. 6–13) and the digression on Africa at Iug. 17–19. The third chapter looks at the political digressions that come at the low points of the monographs, Cat. 36.4–39.5 and Iug. 41–2. For S., Sallust's historical analysis is schematic and reflects his use of history to illustrate political philosophy. The fourth chapter examines Sallust's character sketches to demonstrate that those digressions produce individual examples of larger historical patterns. Contrary to most previous Roman historiography, S. shows that the charismatic individuals in Sallust are reflections of historical forces rather than the true causes of events. Ch. 5 provisionally interprets the geographical digressions in the fragmentary Historiae. The conclusion offers a summary of the book and a brief consideration of Sallust's impact on the later historiographical tradition.

S. offers comprehensive coverage of Sallust's historiography and provides many new interpretations of long-discussed passages. His bibliography is exhaustive and draws together strands of research that have not yet made a significant impact on Classicist-dominated historiographical scholarship, including, for example, recent work by political theorists like D. Kapust (2011) and D. Hammer (2014). He also takes into account recent monographs (both published in 2019) by A. Rosenblitt and J. Gerrish (A. Feldherr's was published too late for consideration), but it is above all the work of A. Wallace-Hadrill and C. Moatti on intellectual exploration of Roman identity in the first century b.c. that serves as his touchstone. S. generally does not find common cause with scholars who emphasise Sallustian uncertainty. He often seeks to resolve tensions and ambiguity, whereas others such as W. Batstone and D. Levene have seen those qualities to be the point. S. insists, for instance, that fortuna is paramount in the famous sentence at Cat. 10.1 where Sallust asserts that Roman history started its decline after Rome had conquered all its rivals, including Carthage (155–8). He is right to note, as others have, that Carthage is merely on the list in a subordinate clause while fortuna is the subject of the sentence. But just as it is overreading to import the concept of metus hostilis into the sentence, it is likewise underreading to suggest that the disappearance of any external threat is just a matter of fortuna. Likewise, S. (271–4) twists himself up in denying the significance of Sallust's application of superbia to Metellus in the Bellum Iugurthinum, since its meaning conflicts with his more expansive interpretation of the dynamics of class conflict in that part of the monograph. Though its readings of individual passages will naturally spark disagreement, with its coverage of the entire Sallustian corpus and a compelling thesis of Sallustian historical vision, this is an excellent book.