[HM] Augustine on the shape of the earth (was: History in Mathematics)

William C Waterhouse (wcw@math.psu.edu)
Tue, 10 Aug 1999 16:18:54 -0400 (EDT)

On August 5, Fernando Q. Gouvea wrote:

**** On Thu, 05 Aug 1999 09:34:41 -0500, Alejandro Montes <amontes@campus.chi.itesm.mx> said:

AM> But Saint Augustine (354-430) flattened the earth again:

AM> "Flat earth arguments usually evolve from literal, naive readings of
AM> the Bible. There's a great Christian precedent for these. Though men of
AM> the fourth century BC understood that the earth was round, Augustine,
AM> seven centuries later, thought otherwise. There couldn't possibly be
AM> people on the bottom side of the earth, because they wouldn't be able
AM> to see Christ come down from Heaven on Judgement Day.." ("The New
AM> Apocrypha", by John Sladek; Granada Pub. 1978)

Does anyone have a reference to the actual passage in Augustine? (Sladek, a
science fiction writer known for his sarcastic humor, may not be the most
reliable of sources...)

---------------
Let me try to summarize Augustine's position(s).There are two
different questions here:
(1) Is the earth spherical?
(2) If so, are there people on the "underside"?

Augustine was sure that the answer to the second question was no,
though not for the reason quoted above. He wrote:

"For there is no untruth of any kind in the Scripture, whose
reliability in the accounts of past events is attested by the fulfillment
of its prophecies for the future; and it would be too ridiculous
to suggest that some men might have sailed from our side of the earth
to the other, arriving there after crossing the vast expanse of ocean,
so that the human race should be established there also by the
descendants of the one first man." (_City of God_ 16, 9)

On question (1), he knew
(a) most pagan philosophers said that it was true, but
(b) the Bible generally presumes a flat earth with a dome of
sky above it and an abyss of water under it.
He did not think that (a) was anything other than a philosophical
speculation, and he himself believed (b). However, he was willing
to say that in the unlikely event that (a) would be fully proved
some time in the future, then the Biblical statements
(which could not be false) would have to be reinterpreted.

Here are some excerpts to support this summary. First,
again from _City of God_ 16, 9, in the original Latin:

"etiam si figura conglobata et rotunda mundi esse credatur,
sive aliqua ratione monstretur, non tamen esse consequens..."

("even if the world might be believed to be a spherical mass,
or if some proof might be given, it would not follow
[that there are people on the other side]").

I cite the Latin to show that the verbs in the "if" conditions
are subjunctive ("esse credatur" and "monstretur"), the "future
less vivid" construction in which the condition is not treated as
particularly likely to happen.

Here similarly is part of the discussion in the _Literal
Commentary on Genesis_ (II,9, 21):

"But, someone will say, don't the people who think the sky is
spherical contradict the Scriptural passage "He has stretched
out the sky like a skin"? Certainly there is a contradiction
if what they say is false; for truth is what divine authority
says, rather than what human weakness conjectures. But if by
chance they might be able ["potuerint"] to prove this by such
evidence that it cannot be doubted, it will have to be
demonstrated that what was said among us about the skin is not
contrary to their true accounts."

Finally, here is another excerpt from the _Literal Commentary
on Genesis_ (I,10,21). Augustine here is arguing that,
when it is night for us, the sun is shining somewhere else.
Obviously this is compatible with both views of the world,
so his choice of presentation shows his own views. Here is
what he says:

In the book called Ecclesiastes it is written:"The sun rises,
and the sun sets, and it draws back to its place," that is,
to the place from which it rose. It goes on to say "At its rising
it goes forth to the south, and turns again to the north."
Thus when the southern part has the sun, it is day for us;
but when it circles around to the northern part, it is night for us.
-- Unless you happen to be inclined to accept the poetic
inventions, so that we should believe that the sun sinks
into the sea at night and, having bathed, rises from it again
on the other side in the morning. But even if this were true,
the abyss itself would be lighted by the sun, and it would be
day there; for it could also illuminate the water..."

Incidentally, Russell's _Inventing the Flat Earth_ (mentioned in
another thread) quite wrongly pretends that Augustine said it
seemed that the earth was round.

William C. Waterhouse
Penn State