The allusions in the title to “rift” and “divide” may throw the reader's imagination back to the early days of the abiding controversy over the relations between science and religion. While the historical reality and nature of an allegedly contentious “religion-science divide” remain unclear, the origins of the historiographical debate are traceable to the late nineteenth century: to John William Draper's History of the Conflict between Religion and Science (1874) and Andrew Dickson White's History of the Warfare of Science with Theology in Christendom (1896). These seminal works mark the locus classicus of the “conflict thesis,” whose core claim is that Western science and religion have historically been and still are at intellectual and political odds. This thesis has since been extensively challenged and revised. John Hedley Brooke, Ronald Numbers, and Peter Harrison, among others, come to mind here as members of a generation of professionally trained historians of science and religion who have systematically examined the subject. Despite numerous qualifications, the “conflict thesis” persists as Galileo's Copernicanism and Darwin's theory of evolution are still viewed as exemplars of a supposedly relentless clash between science and Christianity—between “objective” knowledge and “subjective” faith, reason and revelation, fact and belief.

Although The Great Rift seems to bear a near-obvious relevance to this longstanding body of scholarship, Hobart stays surprisingly detached from it, instead briefly positioning his contribution in relation to more popular writers like Huston Smith, Stephen Jay Gould, and Steven Weinberg. This choice may be a reflection of how Hobart sees himself, as someone confronting this thorny subject from a unique perspective, employing “the history of information technology . . . to narrate and explain the origins of the contemporary rift between science and religion” (ix). Hobart and historian Zachary S. Schiffman utilized a similar approach in their Information Ages: Literacy, Numeracy, and the Computer Revolution (Johns Hopkins University Press, 2000), an ambitious history of “information” from pre-literacy to the close of the last millennium.

The Great Rift is well researched and argued. Hobart guides the reader through a series of transformations in ways of recording, classifying, and analyzing information, from antiquity through the seventeenth-century Scientific Revolution, and examines how these shifts conditioned our culture and worldview. “Instead of seeking yet another set of definitions” for science and religion during this long period, Hobart sets out to “examine the deep substructures of thought that underlie the uncoupling of the two.” The focal point of the rift, he concludes, is the shift between literacy and numeracy. (4)

Describing “the classifying temper,” part 1 connects the creation of the first alphabetic system in ancient Greece to Aristotle's philosophy and its long scholastic shadow. This mentality rose to dominance as “the alphabet brought to its apogee the ubiquitous urge toward greater classification and abstraction . . . it supplied a multilayered distancing of information from the immediacy of our sensory-laden surroundings.” Once words and objects could be associated at an abstract level, “independently of the reader; words have become objective” (41). This then provides the backdrop to Aristotle's efforts to bridge logical demonstrations and dialectical reasoning with metaphysics and epistemology: “to know or understand a thing, thus, meant to define it and thereby locate it in its proper place in the objective hierarchy of all things” (46). Although some of his ideas conflicted with Christian theology, Aristotle's teleological, intelligible, and consistently classified universe furnished the scholastics with a compelling basis for both scientia and religio. Led by the likes of Thomas Aquinas, such intellectual maneuvers attest to the frequently unappreciated interpretive flexibility of Catholic theology. On the eve of the Renaissance and the Scientific Revolution, when the Western worldview was anchored in an information technology based on alphabetic literacy and classification, reason and faith were harmoniously bound.

In Part 2, Hobart points to the Age of Exploration and the invention of the printing press as the chief causes of an “information explosion” that “added to the accumulation of fact and the rupture of classification.” New information technologies surfaced in response to this crisis as “new practices transformed mathematics in each corner of the quadrivium” (88–91). Practical and conceptual developments in arithmetic, geometry, astronomy, and music propelled a fundamental change in the epistemic status of mathematical reasoning. “Thing-mathematics,” in which numbers represented concrete objects, gave way to “relation-mathematics,” in which numbers and other symbols signified empty and abstract relations (97–98). Moving beyond their initial classificatory roles (of counting, measuring, and others), numeracy and mathematics became independent tools of discovery and investigation. Hobart examines in great detail the story of each part of the quadrivium, showing how “businessmen, musicians, artists, and time reckoners alike carved out an abstract, independent, and symbolic arena of information” (222). Yet this section, which spans nearly half of the substantive part of the book, includes only a few fleeting remarks related to the “Religion–Science Divide.”

In “Galileo and the Analytical Temper” (part 3) we finally reach the definitive challenge to the classifying temper. It is represented by Galileo, a canonical hero of the Scientific Revolution, who “recognized that mathematical abstractions could succeed [in explaining the nature] where the abstractions of conventional language could not” (268). Discussions of Galileo in the context of science and religion tend to center on his confrontations with the Catholic Church over his Copernicanism and the interpretation of scripture. Hobart pays conventional homage to the Galileo Affair, but his interest in the new role of mathematical analysis is better served by exploring Galileo's quantification of matter and motion, the subject of his last book, Discourses and Mathematical Demonstrations Relating to Two New Sciences (1638). Reconsidering this well-studied topic from the perspective of information technology, Hobart has interesting things to say about functional dependency as a “linchpin between sensory data and abstraction” and the “process of reverse engineering that lay at the heart of Galilean, modern analysis” (298, 301). Ultimately, however, Galileo is portrayed as a protomodern, a forerunner of Descartes's analytical geometry and Newton's calculus, and an early advocate of the dissociation of nature's authority—represented by numerical relations—from philosophy and theology—captured by linguistic conventions, definitions, and logical deductions.

Hobart's Galileo stands for how the numerical, quantitative, and analytical worldview “etched modernity's imprimatur on the separation of science and religion” (314). A plausible stance in its own right, it often appears to be more presumed than demonstrated. The old adage warning against judging a book by its cover is fitting here, as Hobart's actual case for a “religion–science divide” is much thinner than one might expect. This could also account for his conspicuously superficial engagement with the complex historiographical origins and implications of the “conflict thesis,” a strong version of which this study purportedly upholds. Nevertheless, Hobart's thought-provoking insights, afforded by his history-of-information-technology approach, make the reading of this book a gratifying experience. It should command and will reward the attention of historians of science and mathematics as well as students of Western Christianity and ideas.