"MY HERO," writes Daniel J. Boorstin '34 "is Man the Discoverer." His discoverer-heroes are bold seafarers and careful clockmakers; they are census-takers and historians. Their daring feats to invent clocks and maps and dictionaries that light our way through the night of ignorance.

The Discoverers is itself a heroic book. It is a history of all mankind of what Boorstin calls "mankind's need to know." Such a history leaps the barricades of class and race and nation to show the awakening of our collective intelligence. It affirms the powers of discovery to build in the face of man's powers to destroy. Instead of the crossbow or the cannon. Boorstin tells of the printing press, the telescope, and the microscope.

Boorstin surveys the world through both telescope and microscope. His narrative zooms from panoramic vistas to richly textured details. Only the great French historian Femand Braudel has so well spliced together the grand sweep of history with snapshots of particular events, as in his series on The Structures of Everyday Life.

"To prefer the particular to the universal, the sobering fact to the examinating myth, required both courage and self-denial," Boorstin praises Herodotus and Thucydides, the pathbreaking Greek historians. He demonstrates such courage and self-denial: The Discoverers is chock-full of particulars and laced with sobering facts. We see how the botanist Linnaeus originated the idea of species by looking at the sex organs of plants (and how he inspired Charles Darwin's grandfather to write lyric poems about plants' amours). We learn how fastidious anatomists preserved for centuries their ignorance about the true form of the human body by relegating the unsavory dissection to barber-surgeons, while they read about the body in books.

BUT THOSE who deny pleasure to themselves are all too ready to withhold it from others. The Discoverers is too matter-of-fact. We honor heroes by building myths in their memory; and myths, not facts, give us the passion and the will to be heroes. The passion of discovery shows most readily with the most exotic and most romantic figures, and passages about them are the most interesting in the book Ferdinand Magellan, who "with five barely seaworthy ships would face rougher seas, negotiate more treacherous passages, and find his way across a broader ocean" than any previous explorer, when he sought to circle the globe; Captain James Cook, first to sail to Antarctica, "a frigid continent girded by icebergs, some the size of mountains, others smaller,...all tossed and churned by gutsy winds and unpredictable heavy seas"; Heinrich and Sophia Schliemann, "a quixotic archaeologist with a beautiful wife directing a hundred and fifty rebellious workmen on the exotic Turkish landscape" to find the ruins of Homer's Troy.

But rather than the adventuresome explorer, it is the meticulous instrument-maker who serves as Boorstin's model. His narrative is precise, detailed, and accurate, with only a few minor errors. This is only fitting, indeed, the theme of The Discoverers is "the conquest of common sense" by precise and accurate measurement.

The first step was to confine time within the bounds of human control. Every student of David S. Landes, Coolidge Professor of History, knows all too well how important clocks are for the development of modern society. Boorstin divides The Discoverers into four parts; he devotes the first to "Time." In it, he shows the origins and importance of such commonplaces as the seven-day week and the 24-hour day. "There are few greater revolutions in human history," he writes, "than this movement from the seasonal...hour to the equal hour. Here was man's declaration of independence from the sun, new proof of his mastery over himself and his surroundings."

A particular mastery over our surroundings forms the core of each part of the book. "The Eatth and the Seas" tells of the great explorers who turned geographic fantasy into maps of reality. "Nature" speaks of anatomy; as explorers once wouldn't sail the Atlantic became they believed there was no land to be found. So doctors wouldn't study the body because they thought they already knew all its organs. Boorstin shows the truth of the old chestnut: The first step towards knowledge is to admit one's ignorance. This was as true for the study of society as for that of health. The book's final section, "Society," is its most diverse and complicated, showing how facts replaced myths in the study of the past, how statistics reshape our understanding of the present, and how the printing press "widened the communities of knowledge."

Institutional as well as individual discoverers are the book's heroes. One sees again and again how the same institution would both foster and suppress discovery. For example, the medieval church advanced the development of clocks because monks' routine demanded bells to announce their hours of prayer, but it set back geography a thousand years because its interpretation of the Bible demanded a flat earth.

IN HIS EXCITEMENT over the growth of discovery, Boorstin is concerned about the barriers that contain discovery--fear, complacency, and secrecy. Each barrier is illustrated with varied and memorable anecdotes. The first Portuguese navigators, for example, took fright at the shallow waters of Cape Bojador in Africa. Yet as soon as one ship had rounded the Cape, these same men dared sail any sea, just as the test pilots in The Right Stuff would fly at any speed after Chuck Yeager broke the once terrifying sound barrier.

But the worst enemy of truth, according to Boorstin, is to keep knowledge secret. Warlike states, monopolistic guilds, and closemouthed alchemists all conspired to leave outsiders in the dark. Even Leonardo da Vinci held back the progress of anatomy by keeping to himself his detailed drawings and studies of the human body. "...Despite his consummate art, his industry, and his unexcelled powers of observation, Leonardo added only to his own knowledge, and little or nothing to the anatomical knowledge of his time. Nor were his own observations enriched as they might have been. For, as we shall see, the public forum of printed matter has a way of improving the product, and Leonardo's work remained private."

Boorstin feels strongly that the scholar has an ethical obligation to publish his work and to write for the widest possible audience. He has done both. His many historical books are written to intrigue the citizen as well as the student; they have succeeded, and his Pulitzer Prize is well-merited. Boorstin's faith in the printed word led him to rise at six every morning to write, while holding a more than fulltime job as Librarian of Congress. When The Discoverers quotes Samuel Johnson about writing his dictionary, it could well be referring to its own author; he worked "not in the soft obscurities of retirement, or under the shelter of academic bowers, but amidst inconvenience and distraction..."

The book's one lamentable flaw is its lack of pictures. Its subject is the substitution of careful observation for received opinion; the text would be enhanced if coupled with pictures to observe. Improvements in maps or changes in ideas of the human body cannot be expressed in words along. Nevertheless, The Discoverers makes a fine night table book--not like the coffee table book holding pretty pictures for amusing patter over cocktails, but offering a rich source of new ideas for adventuresome dreams. Matthew L. Meyerson