"It has become a sort of big divide," says Stanley Hoffmann, who has taught at Harvard for 45 years and--like many who favor the historical or institutional approach--may soon retire.

"Rational choice leaves out what makes politics interesting: passions," Hoffmann says.

But rational choice proponent Kenneth Shepsle, who recently ended his term as chair of Harvard's department, says his methodology is attacked simply because it is straightforward in stating its assumptions about human motivation so strongly.

"Others put much less of a premium on putting their premises on the table in a clear fashion," Shepsle says. "It's hard to punch a marshmallow."

Traditionalists admit that rational choice has a place in political science, noting that it has worked well in some predictions about how American government works.

Rational choice, for example, showed that those who would be affected by government regulations would be the only parties likely to try to influence the legislation. And so, counter-intuitively, such regulations often help rather than hinder the industries they are intended to control.

Successes notwithstanding, many of the names that made the Harvard department famous, as well as outside observers, decry rational choice.

The New Republic cites, for example, the method's famous inability to account for why any modern Americans would actually bother to vote, since logic would tell them their vote has no impact and doesn't benefit them.