The Bush presidency can fairly, if tentatively, be judged a failure.

Many partisans take delight in this judgment. But celebrating President Bush's failures is every bit as counterproductive as trying to excuse them.

It's much more useful to examine Bush's administration to see if systems of decision-making contributed to the president's mistakes.

The most serious complaints about Bush (from the left, at least) often center on questions of intelligence — namely that he never had the horsepower for the job. (That is, when liberals aren't claiming that Bush is dastardly. These two accusations, however, are mutually exclusive.)

Certainly, Bush did not, either as a private citizen or a public figure, display any particular intellectual curiosity. Surely this exacerbated the problems he encountered in office.

But there is an argument to be made that Bush's most serious flaw was not a lack of IQ, but rather use of a management philosophy unsuited to the presidency. Lou and Carl Cannon explore this notion at length in their excellent book, "Reagan's Disciple: George W. Bush's Troubled Quest for a Presidential Legacy."

George W. Bush was, the Cannons note, our first M.B.A. president. Politicians of all stripes have talked about the virtues of applying business principles to government for decades. But Bush was the first businessman schooled specifically in management theory to preside from the Oval Office.

Bush's years at Harvard Business School may not have been as formative as, say, Jack Kennedy's days in the Navy. But while there, he was impressed by a certain theory of management.

"Reagan's Disciple" says that Bush was "particularly enamored" of a class called "human behavior and organization." He also was impressed by the work of management guru Peter Drucker, whose essential principle was that good managers should hire smart workers, give them clear-cut responsibilities, and stay out of their way while holding them accountable.

Drucker's theory of management, controversial when Bush was in grad school, is accepted practice today. And it makes sense — lots of very successful businesses are run just so. But while attractive on its face, Drucker's maxim may not be as compatible with the presidency.

To be sure, some fault lay in the execution: Bush hired many bright, impressive people and delegated an enormous amount of responsibility. But he was maddeningly reluctant to hold subordinates — from Michael Brown to George Tenet to Donald Rumsfeld to Tommy Franks — accountable for their failures.

Yet the larger failure of principle may have manifested itself with Vice President Dick Cheney.

Cheney is in nearly every way an admirable figure. His stint as vice president has been, whatever your opinion of his politics, an example of pure public service: He is one of only a thimbleful of men who sought the vice presidency expressly to serve and not as a step on the political ladder.

And upon assuming the presidency, Bush made the more experienced Cheney a hands-on vice president who effectively served as the White House chief of staff.

Or as Carl and Lou Cannon observe, Cheney became chief executive officer and Bush became chairman of the board.

This may seem like a fine arrangement in the abstract. It fits with the Drucker philosophy on the surface: Hire the best guy, give him lots of responsibility, and stay out of his way. But it turns out to have created two systemic problems. First, it may actually be helpful to have a vice president interested in his own political success because this necessarily forces the president to be more attuned to public opinion.

But more important is the structural incompatibility of the two jobs. A chief of staff is an employee who serves at the pleasure of the president. The vice presidency, on the other hand, is a constitutional office. A chief of staff can be fired. A vice president cannot.

If the vice president is acting as chief of staff, it creates a situation where one cannot have disagreement between the president and the man responsible for running the White House, because there is no practical way to resolve such a disagreement.

And disagreement is one of the necessary ingredients for change. One of the striking features of the Bush administration is a dearth of disagreement among the president's advisers.

Disagreement is not always productive, mind you. But when a situation goes sideways, as the Iraq project did in late 2003 and early 2004, disagreement is vital to finding a solution.

George W. Bush is neither the bumbling rube nor the evil genius that his detractors often claim he is. But his administration is an example of how decision-making systems create their own logic, which can cause even smart and well-meaning men to fail.

Jonathan V. Last is a columnist for the Philadelphia Inquirer. Reach him at jlast@phillynews.com.