The myth that the medievals believed in a flat earth

In his Crowhill Weblog (5/17/2004), Greg Krehbiel references an interesting article on "The myth of the flat earth," which was apparently presented originally as a paper at a conference of the American Scientific Affiliation at Westmont College on August 4, 1997, by Jeffrey Burton Russell, Professor of History, Emeritus, of the University of California at Santa Barbara.

It turns out that the myth of widespread medieval belief in a "flat earth" was propagated by two contemporaries, a Frenchman and an American (though no connection has otherwise been established between them). the Frenchman is the antireligious Antoine-Jean Letronne (1787-1848), and the American is the storyteller, Washington Irving (1783-1859). Both of their fictionalized accounts of history have misled many modern scholars and continue to mislead contemporaries.

I grew up believing the Washington Irving myth-- in Irving's fictionalized account of Columbus as the "simple mariner," appearing before a dark crowd of benighted inquisitors and hooded theologians at a council of Salamanca, all of whom believed, according to Irving, that the earth was flat like a plate. But then I came across the following passage in my study of the thirteenth-century theologian, St. Thomas Aquinas' SUMMA THEOLOGIAE (in the opening article of the very first question, reply to objection #2):

Sciences are differentiated according to the various means through which knowledge is obtained. For the astronomer and the physicist both may prove the same conclusion--that the earth, for instance, is round: the astronomer by means of mathematics(i.e., abstracting from matter), but the physicist by means of matter itself. (emphasis added)

Ever since, I have found myself increasingly skeptical of contemporary assumptions about the past. In fact, I have thought about compiling a list of "modern myths" that continue to be widely held in our own times. These might include the pervasive acceptance, still, of (1) Darwinian macro-evolution, (2) belief in global warming, (3) moral relativism, etc.