‘Our Evil Genius’ : BENEDICT ARNOLD; Patriot and Traitor <i> By Willard Sterne Randall (William Morrow: $25; 706 pp.; 1-577-10034-9) </i>

For readers who keep up with Revolutionary War studies, two questions are immediately posed by this book. At 706 pages plus index, what does it tell us about the nascent republic’s most infamous renegade that we do not know from “Traitorous Hero,” Willard M. Wallace’s skillful 1954 biography of Benedict Arnold, which was little more than half as long? What fresh insights does it provide into the events of the summer and early autumn of 1780, when, despite the French alliance, the fortunes of the discordantly united new nation once again hung in the balance (moments acutely examined in Carl van Doren’s “Secret History of the American Revolution” and James T. Flexner’s “The Traitor and the Spy”)? The answers--for this reader--are, to the first question, not a lot, and, to the second, not many. Yet the subject remains compelling. Read on!

Arnold was a brilliant opportunist whose energy, judgment and luck in the heat of crisis carried him far but finally failed to hold. A Connecticut boy, son of a well-to-do Norwich merchant who became an impoverished drunk, and a religious mother with strict notions about how young Benedict should grow up, he seems to have been a pushy, irascible fellow from early on.

Volunteering for military jaunts was preferable to apprenticeship in an apothecary shop. Trading to the West Indies served his ambitions better than staying behind a New Haven counter. The upsurge of dissidence against the mother country handed him a vehicle for his belligerent ardor and for what was quickly evident as innate military ability.

It was a time when all sorts of patriotic amateur soldiers and wheeler-dealers on the make found themselves serving together, and the chances of damaging dispute were often as strong among the rebels as between the rebels and the king’s forces. Even so, particularly massive quarrels attended Arnold, even on his greatest exploits: the taking of Ticonderoga; the march through Maine to Quebec; the naval check given to Carleton on Lake Champlain, and the battles of Saratoga.

By the time he was military governor of Philadelphia, he had been twice wounded in the leg by the British and possibly more wounded in pride by American questioning of his ethics and accounts. His enthusiasm for success as a revolutionary major general was matched by his fierce disgruntlement with Congress and the Pennsylvania authorities.

And then he met Peggy Shippen, young enough to be his daughter, a pretty belle who, during the British occupation of the city, had charmed many young British officers, including John Andre, now aide to Gen. Sir Henry Clinton in New York. It continues to be a moment when one feels almost sorry for Arnold. Knowing as we do how the story turns out, delicious Peggy seems to represent his doom.

Randall clearly has done an immense amount of research. Every byway of Arnold’s saga is diligently examined. Some of this detail becomes irksome, as in his discussion of the Old Light versus New Light religious rivalries in New England, or the three pages devoted to Andre’s pageant, given when the British pulled out of Philadelphia. On the arduous march to Quebec, Randall’s trees often obscure his woods and the reader feels as lost as Arnold’s hungry troops, lugging their heavy bateaux .

A writer with panache might not provoke these criticisms, but the pace of Randall’s writing rarely rises above a steady trudge, with occasional stumbles. A bullet which wounds Arnold is confusingly described as “flattened and sharp.” At one point, Randall tells us that Gen. Gates approved a plan of Arnold’s on Oct. 3; eight pages later he says that Gates hadn’t yet sent his approval four weeks after Sept. 18, which I reckon to be Oct. 16.

He writes of “a highway from Canada north toward Albany,” leading us more than somewhat astray. He attributes the nautical invention of the drop keel or centerboard to the year 1776, although it usually is granted to the Chinese, centuries before, if not to early Colonial boat builders on the Chesapeake. The impression of a writer at an insufficient distance from his mountainous notes is enhanced by the introduction of characters we have already met a few lines before, and Arnold on several occasions being assigned the wrong age.

As for the pivotal figure of John Andre, he does not captivate Randall as he has done other authors. Fair enough. But on matters of age, Randall is mistaken in regarding Andre at 21 years of age, before he joined the army, as “a fixture in England’s literary society.” It is questionble whether Andre was a culprit rather than simply an agent for Gen. Grey in the filchings of Benjamin Franklin’s possessions. Randall calls Andre by turns wealthy and penurious. It is hard to take seriously his hints at a “homosexual affair” between Andre and Clinton, for which there is in fact no evidence (or even suggestion in the so-called gossip Randall prints as apparent testimony). Andre was re-buried in Westminster Abbey, but not in Poets’ Corner.

Despite these considerable demurs, Arnold’s demon draws us along. Even his foes felt the attraction. Lord Germain in Whitehall called him “an enterprising man.” To the Indians he was Dark Eagle. Gen. William Maxwell, a fellow American but no friend, wrote of him as “our evil genius” after Arnold--at the cost of many of his own craft--had brilliantly thwarted the superior British fleet on Lake Champlain. (The historian Alfred T. Mahan credited the success of Saratoga to the year of grace gained by this action at Valcour Bay.)

Randall’s description of this naval engagement is well done. So is his painstaking examination of Arnold’s bookkeeping. Although he brings in new evidence that Arnold didn’t fiddle the accounts of his Canadian expedition, he leaves unchanged our impression that, with his army salary greatly in arrears, Arnold never ceased being a merchant-trader, even a privateer, looking after No. 1.

Randall rightly stresses two factors which would affect Arnold’s loyalty. Congress made the drastic error of passing him over for promotion and hurting his easily hurt feelings. Washington curiously appointed him governor of Philadelphia, where he was soon at odds with the local politicians, living a high life he couldn’t afford and pursuing Peggy Shippen.

He might well have served the American cause best if he had been allowed to follow his amphibious bent, given a fleet and raiding parties and a chance of prize money. As it was, his wounded leg gave him pain--which may have affected his judgment. He was reprimanded by Washington for misusing his powers.

Perhaps, newly married to Peggy, he saw the New World rights of property-owning and money-making for which he had gone to war being diminished by his fellow Americans. Perhaps he was totally exasperated by their inability to work together to keep armies in the field--fed, paid, clothed and properly commanded.

While taking us through all this, step by meticulous step, Randall never quite brings this difficult, apparently unlikeable man to life. What, for instance, did Peggy see in him--a middle-aged man with a limp?

Although Randall lays out the available information and clearly retells the tale of the conspiracy with Andre, he has difficulty, as others have done, in converting Arnold from “patriot” to “traitor”--in getting us to understand this leap, which would have allowed him to surrender West Point, “the key to America,” as Washington called it, and possibly facilitate Washington’s capture. Perhaps one reason for this is that Arnold was never entirely a patriot or a traitor (terms that require only a letter changed and a slight rearrangment to turn one into the other). He kept using the phrase “conscious of my own rectitude” and it was the “my own” that mattered.

Even after he went over to the British, and Andre was hanged, Arnold remained contrary. He took all the blame for his action; he continued to haggle about money. He went on being tactless--praising Washington, damning British inactivity. He gave Cornwallis perceptive advice not to base his army at Yorktown. He went on eagerly seeking conflict, and his customary battle fury brought about a great bloodletting on his home river, the Connecticut Thames.

The closing years, in Canada and London, were not a success, apart from an initial welcome from the king. He sired an illegitimate son in Nova Scotia; all the other sons of the man who had been America’s most effective fighting general became British army officers. Peggy stood by him to the last.