The Information: A History, a Theory, a Flood by James Gleick | Pantheon Books | 544 pages, $29.95

In 1848, on a tour of Europe, Ralph Waldo Emerson met, and was taken with, the restless English mathematician and inventor Charles Babbage. He learned of Babbage’s ambitious plans for his “Difference Engine” calculating device and its symbolic processing successor, the “Analytical Engine.” These were enormous and intricate machines—or, rather, plans for such—requiring innumerable customized gears and pins that, when fit together, would perform fantastic calculations at an inhuman pace. While neither machine could actually be built in Babbage’s era, their conception uncannily anticipated the creation of digital computers a century later. In 1870, a year before Babbage died, Emerson wrote of Babbage’s work and its import: “Steam is an apt scholar and a strong-shouldered fellow, but has not yet done all its work…. It is yet coming to render many higher services of a mechanico-intellectual kind.”

Higher services of a mechanico-intellectual kind. It’s a gorgeous phrase, partly because it hints at the nebulous space between what Emerson could see and what he could not even hope to see. This strange gap points to the first of three grand ideas in James Gleick’s important new book, The Information. It is reasonably easy to look back in human history and learn how a string of visionaries laid the groundwork for discoveries that made possible future innovation. But, as Gleick reminds us, it is much harder for us to understand how their pre-innovation minds actually worked. As he writes, “Every new medium transforms the nature of human thought.”

This is far from a shocking notion in 2011, but what Gleick does in this book, over and over again to a remarkably satisfying degree, is show exactly how it is true. How did the written word actually mark the beginning of logic and consciousness (and what was it like to think before logic existed)? How could the telegraph radically shift perceptions of time, space, and weather (and how did people consider the world before they had a sense of connectedness to other regions)? The book begins in the pre-literate age and marches through the most significant information technology leaps, helping us view each age through its pre-discovery prism.

Gleick devotes a fair amount of space to Babbage not simply because his is a powerful story of curiosity and perseverance, but also because of Babbage’s almost incomprehensible place in the time-idea continuum. He was so far ahead of his own era that he couldn’t possibly understand the greater implications of his ideas. (Nor, of course, could anyone else: the English government terminated its support for the Difference Engine after ten years because it saw no potential use for the device.) “Babbage’s interests,” Gleick writes, “straying so far from mathematics, seeming so miscellaneous, did possess a common thread that neither he nor his contemporaries could perceive. His obsessions belonged to no category—that is, no category yet existing. His true subject was information: messaging, encoding, processing.”

There are dozens of such observations in this book, some of which are undoubtedly not original to Gleick but all of which he conveys with exceptional clarity and economy. Indeed, when collected together into this coherent historical narrative, they do feel “revelatory,” as his publisher claims. (Disclosure: Both Gleick’s publisher, Pantheon, and my publisher, Doubleday, are imprints of Knopf.) They give you a sweeping sense of how much the world has changed, not just in the tools we use and the toys we play with, but in how we think. Gleick is wrestling with truly profound material, and so will the reader. This is not a book you will race through on a single plane trip. It is a slow, satisfying meal.

David Shenk is the author of six books, including Data Smog: Surviving the Information Glut and, most recently, The Genius in All of Us: Why Everything You've Been Told About Genetics, Talent, and IQ Is Wrong. He lives in Brooklyn.