To my mind, the reader would be interested in a review of this book because of its famous author. Therefore, I began by contrasting this biography with the sort of sweeping histories that Ferguson is best known for writing. Ahamed chooses to open with a reflection on the importance of banking in generating our current crisis, and then contrasts Warburg's approach with that of our current financial bunch. We both think Ferguson is a fine historian, but Ahamed faults him for excessive claims for Warburg's significance, while I criticized him for not providing an organically unified and compelling narrative. There's no real disagreement here; in the few hundred words allowed for a review, a critic simply has to make choices.
In sorting out such strengths and weaknesses, I think it helps to clarify just what roles we expect a biographer to play. I addressed this in 2005, in a long review of David Nasaw's definitive Andrew Carnegie, published in Salon. You can read it here. Nasaw, I wrote, researched his book superbly, bringing to light episodes never revealed before. "Researcher, however, is only one of three roles played by a good biographer," I wrote. "Just as important are the parts of historian and writer—the first to explain the times, the second to craft a purposeful narrative. To put it another way, the researcher provides depth, the historian breadth, the writer life."
Of course, a writer may define her purpose narrowly, and not strive for literary excellence. But the truly finest biographers play each of these roles to the fullest. As a researcher, a biographer must plumb not only the doings of the main character, but the lives of those who surrounded that figure, as well as the setting in which the subject's life unfolds. As historians, a biographer must not only understand the context and pass along the information to the reader, but he must also ask fresh questions about the times, and be willing to venture new historical interpretations in order to truly grasp the full significance of his subject. As writer, a biographer must not only integrate the context and facts and events of a life into a continuous narrative, but he must also create expectations, modulate the pacing, explore what this particular life says about the human condition, and write as beautifully as possible.
The danger, of course, is always that one of these roles will overwhelm the others. This is particularly true of the researcher. The massive amount of work that research demands—and the excitement of new discoveries—often create an intense desire to cram it all in a book. As jam-packed as my own The First Tycoon is, it is far shorter than the original manuscript, which included thousands of details about Gibbons v. Ogden, for example, and the lives of such fascinating secondary characters as Parker H. French (the one-handed bandit and confidence man who assisted William Walker in conquering Nicaragua) or Joseph N. Scott (the Accessory Transit Agent in Nicaragua who first went to work for Vanderbilt as a 17-year-old deck hand, learned engineering from the Commodore, and then shifted the history of a half-dozen nations with his sheer obstinancy).
The other roles, however, can sometimes overwhelm a book. When the evidence is lacking, many biographers succumb to extended suppositions of what might have happened, or what someone might have been thinking and feeling. When the historical context becomes particularly fascinating, the main subject can disappear for far too long as the writer examines the times. (I was accused of this by some in my previous biography, Jesse James: Last Rebel of the Civil War.) Sometimes this imbalance is almost unavoidable. If there are no sources on a certain period in subject's life, that doesn't mean this timespan was insignificant. If the context strongly shaped the subject's career, or explains her significance, then a full historical discussion is warranted.
The basic rule in this balancing act is to remember the reader. In each role, the biographer must assure the reader that she being carried forward with conviction and skill, that every element is contributing to the momentum of the narrative. No matter what, a life story cannot become, as history is sometimes called, "one damn thing after another."