When a historian writes a book called “Four Cultures of the West” (Belknap Press, 272 pages, $24.95), we expect a massive, ambitious tome in the tradition of Spengler or Toynbee. But John O’Malley distrusts overarching schemes. Rather than offering a grand theory of decline or progress, he wishes to examine the history of the West to consider the question of the early church father Tertullian: What has Athens to do with Jerusalem? Are our civilization’s profane and religious origins compatible or ultimately irreconcilable?

In the author’s terminology, the four “cultures,” or styles of thought, that have fundamentally shaped the West are the prophetic, academic/professional, humanistic, and artistic cultures. He is careful not to call them “the four cultures,” for he is well aware that they do not capture all features of our society, such as its business or political culture. He picks them to be illuminative rather than exhaustive.

Mr. O’Malley devotes a chapter to each of the cultures, impressionistically describing them via a few representative historical figures. He begins with prophetic culture, the culture of protest and revolutionary reform. Grounded in faith, not reason, it is the only culture of the four that belongs to “Jerusalem.”

Typical of his desultory approach, Mr. O’Malley selects as its exemplars Tertullian, Pope Gregory VII, Martin Luther, and the abolitionist William Lloyd Garrison. A culture of uncompromising vision that views the world solely in terms of black and white, its motto is expressed by Luther’s cry, “Here I stand. I can do no other.” Whereas prophets are fideistic, academics and professionals are rationalistic. Their culture is a style of learning and discourse that consists of relentless analytical questioning and argument. Scholastics such as Thomas Aquinas represent it in its purest form, with Aristotle as its guiding spirit.

Humanistic culture also looks back to ancient Greece, but to Sophists and rhetoricians rather than philosophers. Concerned more with Goodness than Truth, its adherents, such as Cicero and Petrarch, seek to motivate others toward noble ends through eloquence and literature. Unlike academics, who are motivated by a desire for intellectual parsimony, humanists emphasize the difficulty of actual decisions in the real world. Unlike prophets, humanists view the world in shades of gray and seek compromise rather than total victory.

The last culture, the artistic, is the most unlike the others, since it is essentially non-verbal and is concerned with expressing the inarticulable. As Martha Graham, when asked to describe the message of one of her dance pieces, is said to have replied, “If I could define it, we would not have had to dance it.” Wishing above all to enchant its audience, artistic culture is typified by religious iconography and great cathedrals, but especially by ritualistic performance, such as that of the Latin mass.

Peculiarly, Mr. O’Malley, in depicting his four cultures, is far more concerned with their form, their rhetorical style, than their content. Prophets use hyperbole and paradox in their diatribes and declarations. Academics invent precise jargon for their disputations and summae. Humanists make use of metaphor and ambiguity in their allegories, homilies, and imaginary dialogues. Artists, whom Mr. O’Malley clearly struggles to fit into this schema, employ symbolic objects and gestures in their performances and artwork.

A Jesuit scholar of Christian history, Mr. O’Malley’s interest is mostly Christian, with a particularly Catholic emphasis. (In fact, an Internet search suggests that this book’s former title was “Four Cultures of Catholicism.”) It is really the relationship between Athens and Rome that is at the heart of the book. Religion, he claims, must be recognized as the main highway in the road map of Western history. Though he never argues for it explicitly, he obviously assumes the centrality of Christianity in that history.

As befits his emphasis on rhetoric, Mr. O’Malley pays particular attention to the documents produced by epochal church conventions. For example, he claims that the 11th-century Council of Trent, with its sloganeering and denunciations, belongs to the prophetic tradition, whereas Vatican II, with its metaphorical language and calls for dialogue, is humanistic. Much confusion in interpreting such documents, he argues, stems from a failure to recognize the actual culture in which they were written.

Though this might be of interest to specialists and theologians, it is surely less so to the average reader, for whom Mr. O’Malley claims in part to be writing. He says he hopes scholars, educators, and students will appreciate his book. His work benefits from its modest aim and size, but in attempting to appeal to such a wide audience, he ends up with a jarring hodgepodge of styles. For instance, he offers a straightforward narrative of a saint’s life, only to follow it with a sentence such as “The simul of Luther’s paradoxes is paratactic adhesive, not a metaphysical solvent.”

Mr. O’Malley claims that his book belongs to the humanistic tradition, insofar as he intends it to spur contemplation of and a greater appreciation for the accomplishments of the West (and, implicitly, Christianity). Though he achieves this to a certain extent, the scholar of rhetoric would have been even more successful had he paid more attention to his own.

Mr. Shubow is a writer living in New York.