Wednesday, February 23, 2011

Another Ibn Ezra on brain anatomy

Summary: which seems based on contemporary, Galenic science.

Post: We saw in a previous post, regarding zachor veShamor as referring to the same location in the brain, that Ibn Ezra relied on contemporary, Galenic science.  Consider the following pasuk, in Ki Tisa {Shemot 31:3}:

3. and I have imbued him with the spirit of God, with wisdom, with insight, with knowledge, and with [talent for] all manner of craftsmanshipג. וָאֲמַלֵּא אֹתוֹ רוּחַ אֱ־לֹהִים בְּחָכְמָה וּבִתְבוּנָה וּבְדַעַת וּבְכָל מְלָאכָה:
What is the difference between chochma, tevunah, and daat? Well, Rashi explains it as:

with wisdom -- that which a person hears from others and learns.
בחכמה: מה שאדם שומע מאחרים ולמד:

and with insight
understanding something from his heart, from those things which he learned.
ובתבונה: מבין דבר מלבו, מתוך דברים שלמד:

and with knowledge
Divine inspiration.
ובדעת: רוח הקדש:

Ibn Ezra takes a different approach:
[לא, ג]
ואמלא אותו -
כמו: ויהושע בן נון מלא רוח חכמה.
וכתוב: ונחה עליו רוח ה'. ופירושו: מה היא רוח ה'. והיא רוח חכמה ובינה.
החכמה - היא הצורות האצורות באחרונית מוח הראש.

ומלת תבונה גם בינה מגזרת בין. והיא הצורה העומדת בין צורת הדעת ובין צורת החכמה, כנגד הנקב האמצעי במוח הראש. כי החכמה כנגד הנקב האחרון. והדעת המתחברת בנקבי המוח על המצח מההרגשות.
ובלשון ישמעאל קורין:
הדעת אלתכ"ייל.
והתבונה אל"פכרה.
והחכמה אל"חכמה.

והנה בצלאל היה מלא כל חכמה בחשבון ומדות וערכים ומלאכת שמים. וחכמת התולדות. וסוד הנשמה. והיה לו יתרון על כל אנשי דורו, שהיה יודע כל מלאכה כי רבים חכמי לב לא ידעו אפילו מלאכה אחת על כן כתוב: ובכל מלאכה בוי"ו.
"Chochma, Wisdom -- this is the Forms which are stored in the back of the brain in the head.
And the word tevunah, as well as binah, are from the root בין. And this is the Form {?} which stands between the form of the daat {at the front of the head} and the form of the chochma {at the back of the head} corresponding to the middle ventricle in the brain in the head. For the chochma corresponds to the rear ventricle, and the daat which is connected via the holes in the head to the forehead from the senses.

And in Arabic they call daat al-takhayul {=imagination in modern Arabic}, and tevunah they call al-pikhrah {?} and chochma they call al-hokhma."

This is further evidence that Ibn Ezra was working with a contemporary, Galenic theory of brain function. I'll quote from my previous post:

To compare to Galenic science:

Thus, there were three ventricles, or cavities, in the brain. The foremost was connected to sense impression, just as Ibn Ezra writes. The middle one conducts judgement on the sense-impressions. And the back one is memory, to allow even animals to learn from perceptions and remember associations.

This is ancient science, and was the accepted scientific orthodoxy in Ibn Ezra's time. It is not surprising for Ibn Ezra to rely on contemporary science, as he does so in many other instances.

I pointed out in the past post that our modern conception of memory does not accord with Galenic science, and thus Ibn Ezra is incorrect. A commenter, Z, comments there:
And that place is the place of the guarding of the forms

From here

Occipital Lobe - Region in the back of the brain which processes visual information. Not only is the occipital lobe mainly responsible for visual reception, it also contains association areas that help in the visual recognition of shapes and colors. Damage to this lobe can cause visual deficits
I must say that it is pretty neat. It is rather cool when medieval science, or the science of Chazal, or Ayurvedic medicine, accords with modern scientific discoveries or facts. Yet, while it may be rather neat, we should take care not to make this mean more than it does.

In any scientific system, there will be a plethora of facts, both true and false. When one overlays two scientific systems upon one another, there are bound to be overlaps. Yet those overlaps are not meaningful. Thus, one might be impressed by the kiruv proof that Chazal predicted that hemophilia is transmitted through the mother. But, as I explained in this post analyzing this claim put forth by Rabbi Feldman, the fact itself is discernible by mere observation, and one could arrive at this conclusion anyway by applying the erroneous contemporary scientific theory which Chazal propound. To cite myself further:
And we see in the gemara in Niddah (31a) that the mother contributes the blood:

Our Rabbis taught: There are three partners in man, the Holy One, blessed be He, his father and his mother. His father supplies the semen of the white substance out of which are formed the child's bones, sinews, nails, the brain in his head and the white in his eye; his mother supplies the semen of the red substance out of which is formed his skin, flesh, hair, blood and the black of his eye; and the Holy One, blessed be He, gives him the spirit and the breath, beauty of features, eyesight, the power of hearing and the ability to speak and to walk, understanding and discernment. When his time to depart from the world approaches the Holy One, blessed be He, takes away his share and leaves the shares of his father and his mother with them. R. Papa observed: It is this that people have in mind when they say, 'Shake off the salt and cast the flesh to the dog'.
Ancient Greek medicine was a well-developed system. As was Chazal's science. So is modern science. It is no wonder that, on occasion, their paths may cross. That one particular conclusion of one system is matched in a second system does not indicate that they shareassumptions. For years, people went to bloodletters, or applied leeches. This because of false beliefs about the four humours of the body. Yet, in some instances, nowadays bloodletting is a good idea, and has positive effect. This does not mean that it is because those who originally recommended leeches had a deep understanding of modern science.
Z put forth a similar comment in response to my claim that Ibn Ezra was wrong due to following Galen about the extramission theory of sight, that the eyes send forth rays and see at a distance, which is why sight is immediate, while sound takes time to travel to the person:
What do you mean that nowadays we know that its not the case? We know that the lightning happens at the same time as the thunder. We also know that sound travels thru the air in waves and each sound makes a different wave. I dont think he means that an image of the actual letter is made in the air. That would be ludicrous.
As I clarified in the comment section there, what I was speaking of was specifically the extramission theory, in which rays exit the eyes and sense at a distance, which Ibn Ezra explicitly puts forth.

Yes, it is nice when the science of the Rishonim accords with our science. But it does this because of random chance, or because the medieval science was in fact correct about some things. This is not surprising.

However, in terms of making this one part of Ibn Ezra, namely one ventricle out of three, and within that ventricle, one function out of two, correspond to the functioning of the occipital lobe, I have to first wonder what the point would be? This is just luck, that out of the many erroneous scientific points put forth, he hit upon one correct function.

I would also wonder whether the correspondence is indeed there. To cite the function of the occipital love once again:

And that place is the place of the guarding of the forms

From here

Occipital Lobe - Region in the back of the brain which processes visual information. Not only is the occipital lobe mainly responsible for visual reception, it also contains association areas that help in the visual recognition of shapes and colors. Damage to this lobe can cause visual deficits
Ibn Ezra just mentions tzuros, which might correspond to shapes, but not to colors. I suppose memory . storing of these shapes must be done in order to recognize them. Yet it might well be that Galen, and Ibn Ezra, would say that this happens in the front of the brain, where processing of perception happens. I don't know enough Galenic science to say for certain, but this is what it seems from the summary above. Further, I am not sure we know what is meant by tzurot. It certainly means something, and something important. For example (citing Wikipedia), Plato maintained that Form was distinct from substance (think chomer vs. tzurah) and that these forms have an independent, and indeed have the highest and most fundamental kind of reality. It is a sublime philosophical concept, which might well not accord precisely with what we would call forms in English, "shapes".

I'll close with Ibn Caspi's approval yet slight disagreement with Ibn Ezra, in assigning each of these three types of wisdom to the three sections of the brain:

1 comment:

thenutgarden said...

Great blog post, thank you!

“The heart understands. And the [last letter of the word] מוֹחַ [moaḥ] brain, is the first letter of the word חָכמָה [ḥokhmah] wisdom. So too, the last letter of the word לֵב [lev] heart, is the first letter of the word בִּינָה [binah] understanding. And the last letter of the word כָּבֵד [kaved] liver, is the first letter of the word דַעַת [da’at] knowledge. Within these three organs dwell three souls. The vegetative soul dwells in the liver, the animal soul dwells in the heart, and the intellective soul dwells in the brain... This is the tradition that we received from Rabbi Yehudah the Pious of Regensburg” (Rabbi Abraham Abulafia, Ve-Zot Li’Yihudah, quoted in Moshe Idel, Language, Torah, and Hermenutics in Abraham Abulafia, p.2).


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