Monday, July 26, 2010

Ibn Ezra as a Round-Earther

Summary: While there is a seeming Rashi / midrash, and an explicit Mizrachi, in Va'etchanan that the earth is flat, Ibn Ezra on that parasha's haftorah indicates that the earth is round.

Post: In this week's haftorah, we encounter the following pasuk:
הַיֹּשֵׁב עַל-חוּג הָאָרֶץ, וְיֹשְׁבֶיהָ כַּחֲגָבִים; הַנּוֹטֶה כַדֹּק שָׁמַיִם, וַיִּמְתָּחֵם כָּאֹהֶל לָשָׁבֶת
22. It is He Who sits above the circle of the earth, and whose inhabitants are like grasshoppers, who stretches out the heaven like a curtain, and He spread them out like a tent to dwell.
the circle: Heb. חוּג, an expression similar to (infra 44:13) “And with a compass (וּבַמְּחוּגָה),” a circle (compas in O.F.).
and whose inhabitants: are to Him [lit. before Him] like grasshoppers.
like a curtain: Heb. כַדֹּק, a curtain, toile in French.

What is the chug ha'aretz? Ibn Ezra explains that it means the curvature of the earth. Thus:

He points us to Yeshaya 44, just as did Rashi.
ישעיהו פרק מד
  • פסוק י"ג: חָרַשׁ עֵצִים, נָטָה קָו, יְתָאֲרֵהוּ בַשֶּׂרֶד, יַעֲשֵׂהוּ בַּמַּקְצֻעוֹת וּבַמְּחוּגָה יְתָאֳרֵהוּ; וַיַּעֲשֵׂהוּ כְּתַבְנִית אִישׁ, כְּתִפְאֶרֶת אָדָם לָשֶׁבֶת בָּיִת. 

Then he says that this pasuk is ecidence that the earth is round and not square (/flat), despite there not being a requirement for the pasuk to prove this, for the matter is known with complete proofs.

This strikes me as somewhat out of the ordinary. While Chazal certainly take pains to make derashot or bring pesukim to show known things, such as the direction of Bavel or that the sun rises in the East, they had their own reasons for this. But I don't expect Ibn Ezra to be doing such.

Indeed, given that he mentions the competing theory (of רבועה), I would guess that he is trying to convince contemporaries. There are two methods of proof. There is scientific proof, and there is textual proof from Tanach. And different groups would respond differently to these different types of proof. (Rationalists vs. non-rationalists?) And so he brings the pasuk as evidence, while noting the extreme obviousness of this even without the pasuk.

(See the midrash cited by Rashi, and Mizrachi on that Rashi, for the view that the earth is not round but rather flat.)

While I am convinced by the scientific proofs, I am not convinced by the textual proof from this pasuk in Yeshaya. Radak on the pasuk writes:

היושב - כאלו אמר על השמים כי הם חוג הארץ כמו שיעשה אדם במחוגה העגולה, כי למחוגה יש שתי אצבעות האחת יעמוד ובשנית יקיף העגולה והנה הנקודה בתוך העגולה והארץ כמו הנקודה, כי היא התחתון שבעגולה והשמים סביב הארץ כמו העגולה.

ואמר: היושב 
דרך משל, כי אין לו מקום יתעלה מכל דמיון אלא כאדם היושב על מקום גבוה מאד ומביט במקום השפל ידמה לו הדבר הגדול קטן, לפיכך אמר ויושביה כחגבים, כמו שאמר: ונהי בעינינו כחגבים וכן היינו בעיניהם. 

The circle of the earth refers to the heavens. And because of this distance, the inhabitants are like grasshoppers. And even according to flat-earthers such as Mizrachi, the rakia is curved, over the earth.

I don't know about the flat-earth / round-earth beliefs of Radak, but regardless, there is much to recommend this interpretation of the pasuk as it referring to the rakia, on its own merits provided by context.

Update: To counter claims that he was talking of a flat disk, besides what I wrote in the comment about this not being contemporary Muslim astronomy, see also this, from Ibn Ezra's Sefer haTeamim:

He discusses Ptolemy, who works with a spherical Earth, and refers to the earth as a galgal. He clearly knows the Earth is a sphere.


Copernicus said...

How do you know that "round" means a sphere rather than a disc?

joshwaxman said...

you're right. i don't know this absolutely. it was my assumption based on how this was something that was discussed, and proven before this, plus that Ibn Ezra speaks of absolute scientific *proofs*. i don't know of any scientific proofs that it is a disc rather than a four-cornered plane, but this might just be my ignorance of the history of science. was any such clear scientific proof offered? plus, if he is speaking of scientific proofs, then my *assumption* is that he is aware of the cutting-edge science, with its proofs (e.g. shadow on the moon, ships sinking past the horizon), where Islamic astronomy inherited the spherical earth from the Greek astronomical tradition, from Aristotle and Ptolemy. is would be a lot weirder for him to speak of clear scientific proofs to something false, which did not accord with what scientists of his time thought. how would one prove scientifically that at the edge of the plane, it was rounded rather than a right angle?

also, the implication within the pasuk that Hashem was dwelling above the curved Earth, which works conceptually better as a curve in height (just like the firmament) rather than as a flat plate.

i think it is a reasonable reading.

kol tuv,

rabbi sedley said...

I was going to ask the same question. Tosefos in Avoda Zara (41a d.h kakadur) also claims that the world is 'round' but I think that they are referring to a disk rather than a sphere.
Tosefos refers to the story of Alexander going to heaven and seeing the world spread out before him like a 'ball' surrounded by the ocean.
I know that the simple reading of 'ball' (which is the word the mishna uses) is a sphere, but I believe that both the story of Alexander, and the concept of 'surrounded by ocean' imply a round tea biscuit floating in tea, rather than a matza ball floating in chicken soup.
I know that you wrote about the Yerushalmi in your blog already
but there you assume that it refers to a spherical earth, rather than disk shape.
In this wikipedia entry there are many ancient maps which show the world as a flat disk surrounded by water.
It seems to me that this is a more likely reading of Ibn Ezra.

joshwaxman said...

"It seems to me that this is a more likely reading of Ibn Ezra."

why? he lived in Muslim Spain in the 11st century, where standard Muslim astronomy assumed a spherical earth. see here, which i should have linked to initially. and what scientific proofs are there as to the circular shape of the plane? i'll read that wikipedia article carefully, but are you certain that this reflects belief in a flat earth?

to cite that Wikipedia article you linked to:
"This qualitative and conceptual type of medieval cartography represents only the top-half of a spherical Earth."

so don't look at the flat page and assume it is flat. wrap the page around the top hemisphere.

kol tuv,

joshwaxman said...

check the update to the post, where i cite from elsewhere another quote from Ibn Ezra which refers to the earth as a galgal, in a discussion of Ptolemaic astronomy, where Ptolemy maintains the earth was a sphere.

kol tuv,


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