Both men were already known to the Patriot cause before the war's first shots. Both were capable, trusted, and willing to take real risk. The record does not need to moralize the difference between them. It only needs to be read.
On the night of April 18, 1775, Paul Revere, a Boston silversmith and an experienced courier for the Massachusetts Committee of Safety, was sent by Dr. Joseph Warren to ride to Lexington and warn Samuel Adams and John Hancock that British regulars were marching to arrest them and seize colonial military stores at Concord. Revere wrote his own account of the ride shortly after, in a deposition prepared for the Massachusetts Provincial Congress. Both a draft and a fair copy survive at the Massachusetts Historical Society.
I was sent for by Doctr. Joseph Warren... and desired me to go to Lexington, and inform Mr. Samuel Adams, and the Honl. John Hancock Esqr, that there was a number of soldiers, composed of light troops, and Grenadiers, marching to the bottom of the Common, where there was a number of boats to receive them.
The deposition is the corrective to two centuries of poetic myth. Henry Wadsworth Longfellow's 1861 poem "Paul Revere's Ride" made Revere a solitary, romantic hero shouting warnings through every village to Concord. The actual record is more interesting. Revere rode with at least two other riders, William Dawes and later Samuel Prescott. He never reached Concord. A British patrol stopped and detained him in Lincoln before he could finish the ride; Prescott, who knew the back roads, was the one who actually reached Concord with the warning. Revere talked his way free hours later, on foot, without his horse, and walked back to Lexington in time to help carry a trunk of Hancock's papers to safety. The myth has him completing a solo heroic ride. The deposition has him captured, interrogated, and released, having done his job before that happened.
Revere's wartime service continued well beyond that one night. He served in the militia, commanded the garrison at Castle Island in Boston Harbor, and led an artillery unit on the disastrous 1779 Penobscot Expedition, after which he faced a court martial over conduct during the retreat. He was acquitted in 1782. After the war he returned to his trade, built one of the new republic's first successful industrial operations as a coppersmith and bronze founder, and supplied the copper sheathing for the hull of the USS Constitution. He lived to 1818, a respected Boston tradesman whose single most famous night was, in his own account, a job interrupted partway through, not a solo triumph.
Before any of what follows, Benedict Arnold was, by the documentary record, one of the most genuinely capable field commanders the Continental Army had. He helped capture Fort Ticonderoga in May 1775. He led a brutal overland expedition through the Maine wilderness to assault Quebec that winter, losing nearly half his force to starvation and desertion before he ever reached the city. He was wounded in the leg in the failed Quebec assault and again, more severely, at the Battle of Saratoga in October 1777, leading a charge that historians widely credit with breaking the British line and forcing General Burgoyne's surrender, arguably the single most consequential American victory of the war's first half. He did this work while accumulating real, documented grievances: passed over for promotion by Congress in February 1777 in favor of five junior officers, after which Washington personally intervened to have him promoted; accused of financial misconduct as military commander of Philadelphia; and increasingly resentful of what he saw as Congress's failure to recognize his service.
By spring 1779, while still a serving American general, Arnold had opened secret correspondence with the British, using cipher and the alias "Gustavus" or "Monk." By July 1780 he had maneuvered Washington into giving him command of the fortress at West Point, the most strategically critical American position on the Hudson River, and began negotiating directly with British Major John André over what he would deliver and what he wanted in return.
If I point out a plan of cooperation by which Sir Henry shall possess himself of West Point, the Garrison, etc. etc. etc. twenty thousand pounds Sterling I think will be a cheap purchase for an object of so much importance.
There is no ambiguity in this document about motive. Arnold did not write that he had come to believe the cause was lost, or that he had been persuaded the Crown's claims were just. He named a price. The plot collapsed in late September 1780 when André, traveling back to British lines with Arnold's plans for West Point's defenses hidden in his boot, was stopped and searched by three New York militiamen. Arnold, warned just in time, fled down the Hudson to a waiting British ship, escaping minutes before Washington's own men arrived to arrest him. André was tried as a spy and hanged on October 2, 1780. Arnold was never tried. He spent the rest of the war as a British brigadier general, leading raids against the Americans in Virginia and Connecticut, including an attack on New London, Connecticut, near his own birthplace, that burned much of the town.
I have ever acted from a Principle of Love to my Country... I have no favor to ask for myself... I beg She may be permitted to return to Her Friends in Philada or to come to me, as She may choose.
Arnold's own letter to Washington, written the same day his plot was exposed, claims a principle of love of country even as he asks mercy only for his wife, not for himself, and offers no defense of what he had agreed to do. Washington's response was not recorded in kind; his later, measured judgment of Arnold's earlier financial misconduct as "imprudent" while crediting his "distinguished services to his Country" is itself part of the documentary record of how genuinely respected Arnold had been before the betrayal, and how completely that respect was severed after it.
Neither man's record requires interpretation to make its point. Revere's deposition is the corrective to a myth that made him too heroic. Arnold's coded letter is the corrective to any myth that might make him too sympathetic. Read together, the two files are not a study in good versus evil. They are a study in what the primary record actually preserves when a person writes down, in their own hand, what they did and why. One man's hand wrote the truth about an interrupted ride. The other man's hand wrote his own price.