Anyone with even a passing interest in books should take a moment to acknowledge the death last month of Elizabeth Eisenstein, the first person to draw our attention to the momentous impact that printing had on human civilization. Nowadays, panel after panel of historians rank the invention of printing as mankind's most important invention since the wheel. But when Betty Eisenstein advanced that idea nearly thirty years ago, no one had thought of it before.

Her pioneering study "The Printing Press as an Agent of Change", which appeared in 1980, didn't just identify what she termed "an unacknowledged revolution." It also staked out a whole new territory for exploration that is now known and taught across the world: the field of book history. For centuries, of course, bibliographers had been studying books to learn how they were made, sold, and used. But Eisenstein approached the printed book as a historian. Her insight that the technology of printing marked a "phase shift" gave us a whole new prism for understanding intellectual history: the extraordinary spread of ideas that is enabled by a new communications technology.

She was inspired by the insightful yet chaotic ideas of Marshall McLuhan, whose "The Gutenberg Galaxy" was the seed for her life's work. "His ideas didn't work, but he did make me start to think about what might work," she said in an interview for her alma mater, Vassar College, in 2014, as vigorous and tough-minded as ever at the age of 90. To her amazement, no one had ever seriously analyzed the impact of printing on human society before. The act of printing texts, rather than writing them by hand, was a radical novelty to medieval readers, she discovered. There were two key reasons: great numbers of the very same book could appear simultaneously; what was radical was not just the uniformity of a given text, but its multiplicity.

Critics dismissed her as a "McLunatic," arguing that there was less difference between the scribal and printed book than she claimed. But Eisenstein was both a fighter and a consummate scholar. She lived long enough to see her prescience confirmed not just by later scholars but by the next turn of history's wheel. Part of our fascination with Gutenberg's invention is the fact that today we have another radical communications shift with which to compare it. A description of the impact of printing that Eisenstein once cited could well be used at some future time to describe digital technology: "[It]…brought about the most radical transformation in conditions of intellectual life in the history of western civilization…Its effects were sooner or later felt in every department of human life."

It's heartening, too, that she was contemptuous of the "fallacy of supercession": the idea that the new inevitably destroys the old. Doomsday pronouncements about the supercession of print by digital media, for example, were ahistorical. "It's important to study history," she said, "so you have some equanimity about these extreme judgments that people make concerning our own time." Not until I published my own novel about Gutenberg's invention did I have the good fortune to come into contact with this doyenne of printing history. We had more in common than stumbling upon a subject that, amazingly, no one had thought to write about before—me as a novelist, she as an historian. I too was a graduate of Vassar College, in her time a college for women, by my time newly coeducational. I can't help but think that her intellectual rigor and fearlessness derived from that fine institution—a feeling that was only underscored by reading her obituary in the New York Times. Professor Eisenstein, it seems, wasn't only a great scholar, but a senior tennis world champion who was known as "The Assassin."

None of that killer instinct was in evidence when she wrote me last September to thank me for sending her my novel. It was, she said, "an especially appropriate, completely unexpected" advance present for her 92nd birthday. She was "indebted" to me for "producing a book about the first founder of a printing dynasty," she added. I'll never know if she managed to read my story of Peter Schoeffer, the scribe-turned-printer who figured largely in her work as well. But I do know that we are all far, far more indebted to her, a towering figure who showed us just how much we all owe the first printers of Mainz.