“Furthermore, there was no reason for the אר"י to question the eruv of צפת whereas great halachic authorities have publicly forbidden the construction of an(y) eruv in New York City. So there is every reason to question its construction. Also, the אר"י did not question the eruv in צפת after it had already been constructed; our present situation deals with – precisely – the halachic basis for such a construction.”
In fact there was reason to question the eruv of Tsfas. The, “lamdanim and some of the talmidi chachamim,” of Tsfas questioned the eruv since in the non Jewish section of the city there was a street more than sixteen amos wide and some of the streets in the Jewish section opened on to it. On this issue the Maharit Tzahalon (siman 251) commented that for a street to be classified as a reshus harabbim, we require shishim ribo to traverse it. Additionally, these, “lamdanim and some of the talmidi chachamim,” of Tsfas were questioning the existing eruv. (Ironically, the fact is Rav Hirsch’s comments on the Kensington eruv were written after the fact as well.)
Page 3 comment 4:
“But the logic that sees a contradiction because of the “collection of disparate sources” is untenable. Different aspects of any argument may be accepted or rejected, without having to accept the entire thesis. So long as one does not both partially accept and partially reject the same aspect, or selectively accept two aspects of the same argument that are contradictory, one may find one point valid and the other not.”
This is not the argument put forth by the kuntres at all. If the reason that we have to follow Rav Moshe’s zt"l p’sak is because he was the Gadol Hador then why would the anti-eruv group bring other shitos against eruvin (shitos that Rav Moshe never subscribed to) from others whom they do not consider the Gadolei Hador? It must be that the goal is to asser eruvin hence the need to collect shitos yachidos from disparate sources.
To quote The Community Eruv kuntres, “Of course, it is always possible to cite shitos yachidos to invalidate an eruv; however, ruling according to shitos yachidos is not the correct approach in halachah. [The Chasam Sofer writes (Y.D. 37) that if we were to collect all the shitos ha’ossrim we would not be able to eat bread or drink water.] Even more so, in hilchos eruvin, since all criteria have to be met for the area to be classified as a reshus harabbim, even if we were to employ a shitas yachid regarding reshus harabbim that would then disqualify the eruv based on only one criterion, the other conditions would not be met and an eruv would be permissible l’chatchilah. Consequently, to invalidate an eruv, one would have to selectively choose from disparate shitos yachidos ― which in many cases are contradictory ― and that is an unjustifiable approach to halachah. The reality is that if someone learns hilchos eruvin with an open mind, he would realize that since it is almost impossible to meet all the criteria of a reshus harabbim, creating an eruv l’chatchilah is a real possibility.”
Page 3 comment 5:
“Granted, the halacha is not like ר' יהודה; rather, לא אתו רבים ומבטלי מחיצתא. But if the pirtzah is more than 10 amos (maybe 16) that is another matter. In such a case many rishonim would say the entire mechitzah is invalid. R’ Aharon Kotler spends much time in his קונטרס showing this to be the position of the רמב"ם.”
If it’s granted that the halachah is not like Rav Yehudah since most poskim pasken as such, then it’s established as well that the halachah of pirtzos esser is only a rabbinical proscription. As a matter of fact Rav Hirsch admits later (comment 32) that “many” poskim maintain pirtzos esser is d’rabbanan. However, the fact is it’s not just many poskim but the overwhelming majority of poskim who maintain as such (see Pirtzos, Biblical or Rabbinical proscription?). Actually Rav Moshe zt”l maintains that a pirtzos esser is d’rabbanan (Igros Moshe, O.C. 2:89). It is obvious that we don’t pasken like Rav Aharon zt”l (and the Mishkenos Yaakov). If we would pasken like Rav Aharon that pirtzos esser is d’Oraysa and asu rabbim u’mevatlei mechitzta and that a rabbim is less than shishim ribo we would not be able to establish eruvin in any town big or small. [It’s important to note that since Brooklyn’s mechitzos are at the waterfront there is no rabbim traversing them and Rav Aharon would admit that a tzuras hapesach at the pirtzos would be sufficient; see Mishkenos Yaakov, O.C. 122 p. 144.] There is no Rishon who states explicitly that a pirtzos esser is a d’Oraysa – Rav Aharon and others extrapolate from some Rishonim as such. However, the fact is there are three Rishonim who state unequivocally that pirtzos esser is only d’rabbanan (Hashlama, Eruvin 5a; Tosafos HaRosh, Eruvin 17b, and HaEshkol, p. 167). Regarding a pirtzah of sixteen amos even the Mishkenos Yaakov (O.C. 122 p. 144-45) admits to the Bais Ephraim that it is not a qualifier of a pirtzah in a mechitzah.