ohwilleke

The second part of this is most certainly true. There were classical Greek scientists who knew the world is round. The first part is much more iffy. Lots of things which were common knowledge before the fall of the Roman empire, were not afterwards. Isadore of Seville, a medieval scholar who wrote his Encyclopedia in the Middle Ages, has all sorts of crap in there that was clearly understood not to be true in ancient times.

There were a great many people in the time of Columbus who believed that the Earth was flat, the Papacy included, I believe. Columbus, and obviously some others, believed that the world was round (with differing opinions about its size, that of Columbus not necessarily being the most accurate). What it means to say that it was "known in Columbus's time" then, is really an issue of definition. The question is who knew, and more generally how widely the idea was accepted by which groups of people.

For example, one could start by distinguishing betweeen the literate 5% or less, and the illiterate 95%+ of the population. If you included the illiterate, I suspect that popular opinion would be that the Earth was flat (compare this, for example, to people who believe some of the weirder consequences of quantum theory today among non-scientists).

Even among the literate, you could distinguish between the clergy (the largest single group of literate people in 1492 in Southern Europe), and the secular literate group, and among the secular, between people with practical knowledge like navigators and sailors and merchants, and people without practical knowledge like aristocrats. One would suspect that the clergy, who might be acquainted with scripture (which presumes a flat Earth) and church doctrine (which did likewise at some points), would be less knowledgable than secular thinkers, and that those with practical knowledge might be more likely to have the correct belief.

[ September 30, 2002: Message edited by: ohwilleke ]</p>