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Monday, May 4, 2015

Talmud and Game theory

This Wednesday people studying “Daf Yomi” – where the entire Talmud is divided into daily study of 2 folios – both sides of a page, the page studied will be Ketuvot 93.

A case is presented where a person died and his estate had claims by three wives (you may guess what killed him). The Talmud suggests as follows

Wife #1 had a claim of 100
Wife # 2 had a claim of 200
Wife # 3 had a claim of 300

If the estate had a total of 100 – it is divided evenly – 33/3
Wife #1 had a claim of 100 receives 33/3
Wife # 2 had a claim of 200 receives 33/3
Wife # 3 had a claim of 300 receives 33/3

If the estate had a total of 200
Wife #1 who had a claim of 100 receives 50
Wife # 2 who had a claim of 200 receives 75
Wife # 3 who had a claim of 300 receives 75

If the estate had a total of 300
Wife #1 who had a claim of 100 receives 50
Wife # 2 who had a claim of 200 receives 100
Wife # 3 who had a claim of 300 receives 100

What is the logic of the division? The answer had eluded scholars for thousands of years until Robert J. Aumann Nobel laureate solved the question and explained the logic of the Talmud by using game theory
For the simple explanation:

for a more rigorous explanation:

more by Barry O’Neill



Parshiot B’Har & B’Hukotai Dayenu!

Sunday, May 3, 2015

Rabbi Aryeh Kaplan - Age of the Universe

Audio and Essays Parashiot B’har & Bechukotai

Audio and Essays Parashiot B’har & Bechukotai

New Echoes of Eden Project:
Dayenu!
http://arikahn.blogspot.co.il/2015/05/parshiot-bhar-bhukotai-dayenu.html

Audio:
Behar
http://rabbiarikahn.com/audio?id=290

Parshat Behar / Lag Baomer- Guard my Sabbaths
http://rabbiarikahn.com/audio?id=294

Parshat Behar / Shmittah (Matan)
http://rabbiarikahn.com/audio?id=335

Parshat Behar / Shmittah
http://rabbiarikahn.com/audio?id=337

Parshat Behar / The Age Of The World
http://www.yutorah.org/lectures/lecture.cfm/835567/Rabbi_Ari_Kahn/Age_of_the_Universe

Parshat Behar / Were the Details Given at Sinai?
http://www.yutorah.org/lectures/lecture.cfm/793385/Rabbi_Ari_Kahn/Were_the_Details_Given_at_Sinai

Bechukotai-Rebuke – (not) Keeping Shabbat and Shmitta
http://www.yutorah.org/lectures/lecture.cfm/835566/Rabbi_Ari_Kahn/Guard_my_Sabbaths

Parshat Bechukotai / Mikveh Yisroel Yom Haatzmaut
http://rabbiarikahn.com/audio?id=308

Parshat Bechukotai / To Walk Upright Yom Haatzmaut
http://www.yutorah.org/lectures/lecture.cfm/835563/Rabbi_Ari_Kahn/Standing_Tall

Parshat Bechukotai / Walking with God
http://www.yutorah.org/lectures/lecture.cfm/835568/Rabbi_Ari_Kahn/Walking_with_God
Parshat Bechukotai / An Awakening from Below
http://rabbiarikahn.com/audio?id=437

Shemitah, Torah and Har Sinai
http://www.yutorah.org/lectures/lecture.cfm/835556/Rabbi_Ari_Kahn/Shemitah_Torah_and_Har_Sinai

 Shemita and Sinai
http://www.yutorah.org/lectures/lecture.cfm/835559/Rabbi_Ari_Kahn/Shemita_and_Sinai

Shemita Sinai and Gan Eden
http://www.yutorah.org/lectures/lecture.cfm/835562/Rabbi_Ari_Kahn/Shemita_Sinai_and_Gan_Eden

Creating God Consciousness
http://www.yutorah.org/lectures/lecture.cfm/835569/Rabbi_Ari_Kahn/Creating_God_Consciousness

Essays:
Living and Loving

A Time to Trust
http://rabbiarikahn.com/writing?id=151
Audio and Essays Parashat B’chukotai

You CAN get Satisfaction

Coming Home

Standing Tall

The Omer
http://rabbiarikahn.com/writing?id=154

The Great Rebuke
http://rabbiarikahn.com/writing?id=155


Thursday, April 30, 2015

Rav Aharon Lichtenstein, Rav Gustman, and the Legend of the Milkman

Rav Aharon Lichtenstein, Rav Gustman, and the Legend of the Milkman

Rabbi Ari Kahn

For years there has been an urban legend circulating about a chance meeting between two great Talmudic scholars. The story is usually told as follows:

During the Yom Kippur war, the Rosh Yeshiva of Yeshivat Har Etzion, Harav Aharon Lichtenstein ZT”L, felt compelled to help in the war effort. His students were fighting valiantly at the front, and he felt the need to pitch in. Rav Aharon approached the Home-Front Command (or, in some versions of the story, the Jerusalem Municipality) and volunteered his services. A local milkman had been called up as an IDF reservist, and Rav Aharon gladly took over his delivery route.

One of the people he met on his route was the revered Rosh Yeshiva of Yeshivas Rameilis - Netzach Yeshiva, Rav Yisrael Ze’ev Gustman ZT”L. During this serendipitous meeting, the two Talmudic titans began discussing Talmud. Rav Gustman had no reason to believe that the clean-shaven milkman was, in actuality, a prominent Rosh Yeshiva. Duly impressed, Rav Gustman later remarked to one of his students how lucky he was to live in Jerusalem – where even the milkman is a “baki b’shas” (well-versed in the entirety of Talmud).

There are several problems with this story, the most serious of which is that the meeting it describes never happened. Here are some historical facts to consider:
·      Rav Aharon never volunteered as a milkman.
·      Rav Aharon and Rav Gustman were well acquainted long before this story supposedly transpired. When the Lichtenstein family moved to New York they lived in close proximity to Rav Gustman; Rav Aharon first met Rav Gustman when the former was still quite young. If memory serves me well, I was told that Rav Aharon  “inherited” his approach to some of the laws of blowing the shofar from Rav Gustman. Rav Aharon accepted as authoritative the sounds he had heard in his youth in Rav Gustman’s Beit Midrash.
·      Rav Aharon was well-known throughout the yeshiva world as a prodigy. Having grown up in the Crown Heights section of Brooklyn, where Rav Gustman lived and taught, it is highly unlikely that Rav Gustman did not know who Rav Aharon was. Additionally, Rav Aharon was a leading student of Rav Yitzchak Hutner, who was a very close friend of Rav Gustman; it is unlikely that the two Roshei Yeshiva did not discuss Rav Hutner’s brilliant young student.
·      My brother, Rav Yair, told me that on one occasion he went to speak with Rav Gustman about a complicated Talmudic passage. Rav Gustman asked him where he learned; when he informed him that he was a student at Yeshivat Har Etzion, Rav Gustman responded, “Your Rosh Yeshiva is a great Talmud Hacham. Why are you asking me? You should be asking Rav Aharon.”
·      I personally recall seeing Rav Gustman at the Bar Mitzvah celebration of one of Rav Aharon’s sons.
·      Rav Aharon’s son told me that on Simhat Torah in 1973, while the Yom Kippur war was still raging, Rav Aharon took him and his brothers to the Netzach Yisrael Yeshiva for Hakafot. (As a Hesder yeshiva, Rav Aharon’s Yeshivat Har Etzion was empty: all the students were at war.)

All of these facts would seem to indicate that the story is no more than an urban legend. On the other hand, I was told many years ago that during the Yom Kippur war Rav Gustman had volunteered in a local hospital. The hospitals were short on staff, and Rav Gustman would spend his nights in the hospital, lending a hand and doing whatever he could to help out. This was his way of taking part in the war effort in a constructive way.

As I heard it, Rav Gustman came to the hospital every night. He helped change sheets, transported patients to and from operating rooms, and whatever else was needed. Before long, Rav Gustman struck up a friendship with one of the other young men who had come to volunteer, an earnest yeshiva student from overseas. This young man brought his Gemara, and when there was a lull in activity, he opened his Gemara and started to learn. Glancing up from his book, he noticed the elderly volunteer and asked if he would like to learn with him. The young man then proceeded to “teach” Rav Gustman Gemara during those precious moments of down-time in the hospital.

A few weeks later, this young yeshiva student received a warm recommendation from a fellow student, who told him about an exceptional Talmudic genius who had survived the Holocaust and was currently a Rosh Yeshiva in Jerusalem. The scholar, he was told, had been a dayan in the Beit Din of Rav Chaim Ozer Grodzinski; in fact, he was the youngest scholar ever appointed to the famed Beit Din of Vilna.  The young volunteer seized the opportunity and went to hear a shiur from this great scholar. When he entered the Beit Midrash of Yeshivat Netzach Yisrael, he was shocked to see that the illustrious Rosh Yeshiva was none other than his chevrusa from the hospital.

Both of the stories repeated here are plausible, possible - and in the case of the second story, actually true – because they share one underlying element: the unassuming bearing and immense modesty of both Rav Aharon Lichtenstein and Rav Yisrael Zeev Gustman. I consider myself profoundly fortunate to have studied with both of these great men.

But what of the milkman? Recently, when I visited the home of the Lichtenstein family to pay a condolence call, I expressed my skepticism regarding the veracity of the milkman story, and asked Rav Aharon’s family if they had any idea how this urban legend got started. Was there another unassuming, clean-shaven baki b’shas wandering the streets of Jerusalem?
I was given the following answer:

When Rav Aharon Kotler came to visit Israel (where his father-in-law Rav Isser Zalman Meltzer was a leading rabbinic figure), there was some pressure placed upon him to stay and take on a post as a Rosh Yeshiva in Jerusalem. Rav Aharon (Kotler) responded that he had met a milkman that morning in Jerusalem, and the man was proficient in all of Shas. Rav Aharon opined that in Lakewood, where the public is generally ignorant, he would be able to be a Rosh Yeshiva, but in Yerushalayim, where even the milkmen know all of Shas, he feels out of his league.

Apparently, “Rav Aharon” (Kotler), the protagonist in the original milkman story, was exchanged for Rav Aharon (Lichtenstein) in the later version of the milkman story; such is the nature of storytelling. Whether there ever was such a milkman or not – only Rav Aharon knows.




Sunday, April 26, 2015

Parashat Emor 5775 Teach Your Children

Audio and Essays Parashat Emor

 Audio and Essays Parashat Emor

New Echoes of Eden Project:
http://arikahn.blogspot.co.il/2015/04/parashat-emor-5775-teach-your-children.html

Audio:
Extension of Holiness
http://www.yutorah.org/lectures/lecture.cfm/812384/Rabbi_Ari_Kahn/Extension_of_Holiness

Parshat Emor / Holiness From Above And From Below Lag B Omer
http://rabbiarikahn.com/audio?id=297

Parshat Emor / Ish Tam
http://rabbiarikahn.com/audio?id=300

Parshat Emor / Why Is The Story Of Blasphemer In Vayikra
http://rabbiarikahn.com/audio?id=317

Parshat Emor / Shabbat
http://rabbiarikahn.com/audio?id=330

Parshat Emor / The Son Of The Egyptian Man
http://www.yutorah.org/lectures/lecture.cfm/775145/Rabbi_Ari_Kahn/Parshat_Emor_5772_why_is_the_story_of_the_blasphemer_in_Vayikra

Parshat Emor / The Dual Aspects of Sefirat Haomer
http://www.yutorah.org/lectures/lecture.cfm/792809/Rabbi_Ari_Kahn/The_Dual_Aspects_of_Sefirat_Haomer

Essays:
The Story Behind the Story
http://rabbiarikahn.com/writing?id=148

The Omer - Bread from Heaven
http://rabbiarikahn.com/writing?id=149

The Quality of Innocence
http://rabbiarikahn.com/writing?id=150

An Extension of Holiness