At 12:33 PM 12/14/97 -0500, Ted Davis wrote:
>Glenn Morton has posted several things about Magellan, and what his voyage
>is alleged by some to have "proved." He mentions an exchange (off board)
>between us, some time ago, concerning the matters he is now putting up
>on-line.
>
Lets correct one thing. I didn't start this exchange, Don Page did by
posting an old post of mine. I rethought the issue and thought maybe I had
found what it was that bothered the people about the voyage in regards to
the Ptolemaic system. I may be wrong on that but haven't seen an analysis
yet that doesn't simplify the problem to the unrealistic case co-revolving
spheres. There is much more complexity about it than that. I posted the
Manchester quote because George asked if any historians believed this. Well
one does. :-) I decided to try to find out once and for all if this thing is
correct or not. I occassionally (ok, often) write dumb things I wanted to
verify at least part of the story.
>What I find plausible in the stories is mainly this: that the sailors who
>landed in the Cape Verde Islands at the end of their circumnaviation found a
>discrpancy about what date it was, differing by one day with the locals.
>This would not only be correct scientifically, but seems correct
>historically also. I can find no reason to doubt the accounts, which
>apparently cite primary sources to this effect.
>
>What I cannot accept, however, is mythological claims such as the following,
>which Glenn quotes at length:
>
> "During the Dark Ages literal interpretation of the Bible
>had led the Church to endorse the absurd geographical dicta of
>Topographia Christiana, a treatise by the sixth-century monk
>Cosmas. Cosmas, who had traveled to India and should have known
>better, held that the world was a flat, rectangular plane,
>surmounted by the sky, above which was heaven. Jerusalem was at
>the center of the rectangle, and nearby lay the Garden of Eden,
>irrigated by the four Rivers of Paradise. The sun, much smaller
>than the earth, revolved around a conical mountain to the north.
>The monk's arguments were fragile, and not everyone accepted them
>- the Venerable Bede, among others insisted that the earth was
>round - but Cosmas scorned them. Rome agreeing with him,
>rejected their protests as an affront to common sense.
> "This patristic dismissal of so elementary a fact was a sign
>of how deeply the wisdom of the ancient world had been buried.
>More than three hundred years before the birth of Christ,
>Aristotle had determined that the planet must be a sphere; after
>an eclipse he pointed out that only an orb could throw a circular
>shadow on the moon. The existence of India and Spain was known
>in Athens. "
>~William Manchester, A World Lit
>Only By Fire: The Medieval Mind and the Renaissance: Portrait of
>an Age, (Boston: Little, Brown & Co., 1992), p. 230
>
>It's this kind of BS (that's the only term I can think of that accuractly
>conveys my meaning, please forgive) that gets my hackles up. Cosmas was one
>of only two persons we can name in the Latin West, after the time of Christ,
>who believed in a flat earth; from this isolated fact, Manchester follows a
>long, illustrious, and unsupportable tradition into mythmaking, by making
>Cosmas the symbol of a collection of patristic writers who said nothing of
>the sort. Manchester is a prize-winning historian, but not when he writes
>about the "Dark Ages" -- a term that no contemporary scholar of that period
>uses, to the best of my knowledge, because it conveys precisely the kind of
>erroneous notions that Manchester should have known better than to believe.
>Myths like the "flat earth" and the "warfare of Christianity and science,"
>which incidentally are closely linked, are awfully easy to spot in
>historical writing. Ask a couple of questions: (1) is "reason" being used
>to show how "utterly foolish" Christians were? (2) can you hear the
>orchestra coming to a crescendo as the hero steps into the center of the
>stage and stands up for "truth"? If the answer to both questions is "yes,"
>there is an awfully good probability that you're reading BS that passes for
>historical scholarship. Not always, but very often. Get your antennae up.
I want to clarify that my interest in this is not the myth of the stupid
Christian which you correctly denounce but whether or not there is a kernal
of truth here that is blown up by Manchester. I think I had said in one of
my posts that your concern was that Manchester was wrong.
>
>Ted Davis
>
>PS. Glenn might be on to something about Magellan and Ptolemy, in terms of
>the technical details and what his voyage was LATER understood to have
>accomplished. I don't know, but he might be. I suggest that he write up
>what he finds and send it to Owen Gingerich, or to the Journal for the
>History of Astronomy, in which case Owen will eventually see it anyway. It
>sounds plausible, at any rate. However, it is worth noting that Magellan's
>voyage can't possibly have been taken for "proof" of Copernicanism at the
>time. Although Copernicus' ideas were circulating informally from c. 1512,
>his book wasn't printed until 1543, and we know of fewer than a dozen people
>in the whole world who believed him concerning the earth's motion prior to
>the time Galileo used a telescope to see a bunch of hitherto unknown things,
>in 1609-10. None of those Copernicans, to the best of my knowledge, ever
>linked Copernicanism with Magellan. Once again, we might have the makings
>of a myth here.
Not that this might or might not have had any impact on the issue, it is a
historical fact that Copernicus was not the first person to believe in a
heliocentric universe. The Pythagorean Philolaus "...was the first, as far
as we know, to introduce the concept that the earth is in motion.
Apparently he held that it is too base to occupy the center of the universe,
and assigned a central fire to that position. About the fire revovled the
earth and other planets." George Abell, Exploration of the Universe, (New
York: Holt Rinehart and Winston, 1969), p. 15
other ancient greeks who held this view were Hicetas, Heracleides and
Ecphantus. (ibid. p. 16)
So even if the problem with the model and circumnavitation is true, they
were most likely NOT confirming Copernicus' view of motion (because they
would not necessarily have heard of it) but might have heard of some of the
earlier views. All I could say is that it would be possible.
>
>
>
>
glenn
Adam, Apes, and Anthropology: Finding the Soul of Fossil Man
and
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm