Sunday, June 19, 2016
The argument: Aside from the different sources that indicate the intent is not one place, but the city as a whole, upon closer examination, as explained at length in Dober Shalom, p. 131, the argument that the intent is one place is entirely untenable. In the Talmudic era, by and large, people did not pass through the streets at night. Thus, a day refers to a twelve hour period. In such a period, there are 84,000 seconds. Hence, for 600,000 people to pass by a particular place in one day, 15 people must pass by every second over the duration of those 12 hours. Obviously, no such place has ever existed. Thus, the intent is not a specific place, but the city as a whole. Thus, when discussing this issue, the Alter Rebbe mentions (sec. 357:7) "a large city which possesses 600,000 inhabitants and (sec. 392:1) "a city with a large populace." For this reason, Rav Moshe Feinstein (Igros Moshe, Orach Chayim, Vol. 1, responsum 139) ruled that an eruv that includes Brooklyn as a whole may not be constructed.
The rebuttal: There is no one of stature who indicates that shishim ribo is conditional of a city.
Regarding Rabbi Levine’s claim that it is physically impossible for the criterion of shishim ribo to be conditional of a street, he is toeh b’dvar Mishnah. He calculates the number of people traversing a given part of a street as one person per second, but a person's gait is more like two or three steps per second (see the calculations in Meseches Pesachim, 94a). Hence, it would only take approximately five hours for shishim ribo to traverse a street.
In regards to the Alter Rebbe, they are totally mistaken. As I mentioned previously, there is no doubt that from siman 364:44 we see the Alter Rebbe understands that shishim ribo is conditional of a street. There is no reason to create contradictions in the Alter Rebbe’s Shulchan Aruch when we can explain it simply. In both references that they listed, the Alter Rebbe is referring to a city whose population of shishim ribo traverses its main street. [Moreover, the first source listed (357:7) is a total misunderstanding on their part, see note  below.]
Regarding Rav Moshe Feinstein zt”l, they are missing the point. To begin with, I think that it is essential to give an overview of Rav Moshe’s chiddushim in shishim ribo.
Like most poskim, Rav Moshe originally maintained (Igros Moshe, O.C. 1:109) that the criterion of shishim ribo was dependent on the street having shishim ribo traversing it. However, later (ibid., 1:139:5) he formulated his chiddush in which shishim ribo, when applied to a city (see further regarding a sratya), was not dependent on a street but over a twelve mil by twelve mil area. Rav Moshe added that the criterion of shishim ribo ovrim bo would require a sizable population living and commuting into the twelve mil by twelve mil area so that it could physically satisfy the condition of 600,000 people collectively traversing its streets. When these criteria are met, the area would be classified as a reshus harabbim. However, at this time, Rav Moshe did not quantify how many people would be required to live in this twelve mil by twelve mil area.
In the first teshuvah quantifying how many people would be required to live in this twelve mil by twelve mil area, Rav Moshe stated (ibid., 4:87) that since in the past eruvin had been erected in cities with populations exceeding shishim ribo, one could not classify a city as a reshus harabbim solely on the basis of the existence of a population of 600,000. He then added that, although the actual number of inhabitants could possibly vary according to the city, in Brooklyn it would most likely require four to five times shishim ribo. In the final two teshuvos which followed regarding Brooklyn, we see that Rav Moshe codified his chiddush that the requirement is, "just about three million people," (ibid., 5:28:5) or, "at least five times shishim ribo," (ibid., 5:29) which could amount to even more than three million people. [There are three reasons why Rav Moshe would allow an eruv in Brooklyn today, including that the population is less than three million over a twelve mil by twelve mil area and that Brooklyn is encompassed by mechitzos; see http://eruvonline.blogspot.com for an in-depth analysis.]
Consequently, Rav Moshe’s shita regarding shishim ribo should not be conflated with Rabbi Levine’s. Rabbi Levine is suggesting that the criterion of shishim ribo is conditional of the population of a city. Rav Moshe maintains that shishim ribo is conditional of 600,000 people collectively traversing the streets of a twelve mil by twelve mil area. Rav Moshe explicitly states that eruvin were erected in the past in cities with populations exceeding 600,000 people.
Furthermore, while Rav Moshe maintained that the criterion of shishim ribo, when applied to a city, was not dependent on a street but over a twelve mil by twelve mil area, he admitted that from a simple reading of the Shulchan Aruch (shishim ribo ovrim bo b’chol yom) it is more plausible that the criterion is conditional of the shishim ribo traversing a particular section of a road (ibid., 1:139:5). Consequently, Rav Moshe posited that the Shulchan Aruch is only referring to a sratya [intercity road], in which case the shishim ribo would need to traverse a particular section of the road on a daily basis in order to be classified as a reshus harabbim (ibid., 4:87, 5:28:16). Accordingly, it is a greater chiddush for those who follow a strict reading of the Shulchan Aruch to argue that the criterion of shishim ribo is conditional of a city and not of a street.
 In this English translation, the number of seconds in a twelve hour time period is incorrect. There are 43,200 seconds in twelve hours.
 This is incorrect. Rav Moshe’s opinion was not influenced by the Alter Rebbe and definitely not by any of the arguments set forth by Rabbi Levine. Additionally, the mareh hamakom in the Igros Moshe should be O.C. 4:87-88, and 5:28.
 הנה השוע"ר כתב שם דמ"מ שייך למיגזר בעיר גדולה שיש בה ס' רבוא. והנה לבד מה שהזכרנו דבעיר גדולה בימיהם היו בוקעים ס' רבוא בדרך המפולש של הרחוב המרכזי, מ"מ כאן בלא"ה אין שום סרך ראיה לדבריהם, כי הרי בעיר גדולה אסור כוחו בכרמלית כמו שכתבו התוס' (עירובין פ"ח ע"א ד"ה הני תיימי) דחיישינן שילכו המים עד רה"ר לכן משום לא פלוג גזרו כל כוחו בכרמלית, ע"כ הוצרך השוע"ר (המג"א) לומר דגזרינן בתוך עיר גדולה של ס"ר על כוחו בכרמלית, שהרי הגזירה הוא על הכרמלית שבעיר, ואטו עיר גדולה גזרו על עיר קטנה, משא"כ חוץ לעיר דלא שכיח רה"ר בזמה"ז לא גזרו על כוחו בכרמלית. ופשוט דאין מדברי השוע"ר (המג"א) הנ"ל שום ראיה לדבריהם כלל וכלל, כי אין מדובר כאן מרה"ר, אלא מכוחו ב"כרמלית" שגוזרין בעיר גדולה.