Roger Shattuck’s Forbidden Knowledge is a wide-ranging investigation of the tension in Western Culture between the impulse to aggressively seek knowledge wherever it may lead, and the instinct to censor that which should not be known. Following two paths, a history of Western literature and an investigation into contemporary science, Shattuck concludes that we are mistaken to pursue knowledge for its own sake and that censoring literature has value. While much in this book is provocative and instructive, Shattuck leaves us without clear criteria for what he thinks ought to be forbidden.

Shattuck identifies what is essentially modern about the West. "We believe that the free cultivation and circulation of ideas, opinions, and goods through all society (education, scholarship, scientific research, commerce, the arts, and the media) will in the long run promote our welfare. We also believe that we can contain the social and political upheavals into which these same cultural enterprises have launched us."

Looking at stories we have told ourselves, Shattuck does not find this view supported. For every Prometheus, there is a Pandora, and "ignorance may not be bliss, but the observation of prudent restrictions on knowledge might have prevented the fate of Orpheus, of Icarus, and of Lot’s wife."

Essentially, Forbidden Knowledge embodies a paradox: it’s a book that wants to know what it is we should not know. This paradox forms the dialectical engine of the argument.

Along the way, Shattuck’s intellectual depth and literary breadth are impressive. He examines with vigor and insight many of Western literature’s greatest hits, from Dante to Milton, from Montaigne to Pascal, from Faust to Frankenstein. In each of these stories, Shattuck finds instruction on the uses of knowledge and the consequences of overreaching. The book’s point of view, while cosmopolitan, is in fact a plea for the oldest of virtues, the Greek notion of sophrosyne, or moderation.

Having established the terms of his argument in literature, Shattuck turns to science, examining atomic bomb research and, most extensively, the human genome project, which seeks to map the complete DNA sequence of a human being. He suggests four categories—practical, prudential, legal, and moral—that we should consider when deciding whether limits should be placed on scientific research. Replying to potential critics who argue for unbridled "pure" research while limiting practical applications of it, Shattuck says that "The frontier between pure and applied is a phantom that appears on many maps yet cannot be located easily on the terrain."

However, Shattuck reserves most space and scorn for the current darling of literary critics, the Marquis de Sade. Tracing Sade’s critical rehabilitation from an insane pornorgrapher to one of the giants of modern Western literature, Shattuck argues that "Sade’s writings confront us with the extreme attempt in Western culture to strip away the constraints of civilization in order to return to barbarism."

Shattuck’s analysis leaves no doubt as to his view of Sade’s defenders. "Sade’s writings exploit a new form of what I shall call ‘civilized taboo.’ After four millennia of religion and philosophy and statecraft have gradually differentiated between holiness and pollution, Sade sets out to confound them again. By manipulating fear and fascination, he tries to confer holiness on our most deeply polluted impulses, and vice versa. Anyone who does not register a sense of taboo in reading Sade lacks some element of humanity."

In essence, Shattuck believes we should show restraint in what we allow to be made public, in both science and literature. For him it is a matter of balance: "We need to weigh the advantage of free speech and the unimpeded circulation of ideas against the advantage of a balanced environment for the young to grow up in and for the mentally unstable to survive in without doing harm to themselves and others."

Forbidden Knowledge is an impressively wide-ranging investigation into the positive social role taboos play in society, written by one of our most distinguished literary critics and biographers. However, he classifies a series of types of forbidden knowledge without saying who (elected officials?) should decide what is forbidden. He provides the reader with little indication as to how one would, given two pieces of literature or two scientific experiments, determine what ought and ought not to be forbidden.

In practice, no Western society, including our own, has lacked for censorship of both the arts and scientific investigation. What is needed is a method by which we can strike the balance Shattuck promotes.

Forbidden Knowledge should be read as an imposing contribution to a national debate across the arts and sciences on the issues of freedom and restraint. Yet, what is missing from Shattuck’s account shows us that we still have a long way to go in understanding the difference between the accepted and the taboo.