In a prior post, I quoted R. Joseph B. Soloveitchik as writing, "The Halakhah is completely integrated with the natural process. It never takes cognizance of any causalistic anomalies." Following up on that, I hope to address in this post the role of miracles in halakhah. Note that this is not arguing that miracles do not occur. Rather, the claim is that halakhah is about the natural world and does not allow miracles into its functioning.
1. The Mishnah (Yevamos 121a) discusses the case of a man who falls into water. Is that sufficient to assume that he died and his wife may remarry? The initial view in the Mishnah is that it is not sufficient. R. Meir adds that there was once a man who fell into water and emerged after three days. Clearly, then, a man falling into water and remaining there for days does not mean that he did not die.
The Gemara (121b) states that the Sages said to R. Meir that we do not take into account miraculous events. The ensuing discussion makes it clear that even R. Meir would agree to this, but could conceive of a non-miraculous way of a man to survive lost at sea for three days.
The upshot of this is that we do not assume that since a man could miraculously survive any particular scenario that we must therefore not be convinced that he has died. We simply do not take miracles into account in halakhic decision-making.
2. The Gemara in Makos (5a) says that if eidim zomemim (witnesses who testify that other witnesses are lying) say that witnesses were with them in one place in the morning and they were testifying that they saw something in another place in the evening, we check to see if the witnesses could have traveled that distance in the necessary time to have been with the eidim zomemim and still witness what they claimed to have seen. But, the Gemara asks, this is obvious! However, one might have thought that we account for the possibility of a super-fast ("flying") camel through which the witnesses could have traveled the long distance and this comes to tell us that we do not. In other words, we again see that we do not take miracles into account in making halakhic evaluations.
3. However, the Gemara in Yevamos (116a) relates the case of a get (divorce document) with an unusual name that was written in one place and the only person with that name was witnessed to be in another place on the day the get was written. Are we concerned that this get might be good? Rava says that we are concerned because he might have a super-fast camel, or have jumped from one place to the other (Rashi: using the name of God), or started proceedings in his place that continued elsewhere. The implication here is that we do take into account miracles in regard to the status of a get. (Cf. E. Urbach, The Sages, p. 113)
Tosafos (ad loc.) offer two explanations for this difference. Rabbenu Tam says that regarding a get, it is plausible that an estranged husband would go to extreme lengths to hurt his wife. However, there seems to be no reason why a potential witness would go to such lengths. Rabbenu Menachem says that witnesses should have said that they experienced a miracle and, since they did not, we can assume they are lying. According to these two views in Tosafos, we take miracles into account when appropriate.
However, the Raavad II (R. Avraham Av Beis Din, father-in-law of Raavad III) is quoted as explaining that the miracle is not really a part of the Gemara's conclusion; it was really focusing on the husband having started the proceedings elsewhere. This position is accepted by the Ramban, Rashba, Ritva, Tosafos Rid and Nimukei Yosef. According to the Gra, cited in the margin of the Vilna Shas, this is the position of all authorities other than Tosafos. Thus, the consensus seems to be that miracles are not incorporated into halakhah.
4. Prof. Saul Lieberman (Greek in Jewish Palestine, p. 110) points out that according to Resh Lakish in the Jerusalem Talmud (Nazir 8:1), a man can claim that he had relations with a woman because of sorcery (keshafim). However, the Babylonian Talmud (Yevamos 53a-b) seems to reject that claim by ommission. Once again, the accepted halakhah does not take supernatural considerations into account.
5. The Mishnah (Berakhos 54a) records an obligation for a person to recite a specific blessing upon seeing a place where a miracle occurred to him. Does this imply that halakhah acknowledges miracles? This is where things start to get confusing. There is actually a debate among medieval authorities whether the blessing is to be recited on miracles that deviate from "the way of the world" or not. This would seem to be a debate over whether the "miracle" of the Mishnah is just an unlikely event or something entirely supernatural. However, none of the examples given are of what we would call supernatural occurrences. For example, the Avudraham, which the Beis Yosef (Orach Chaim 218) quotes partially, includes the miracle of Purim as one that is not in "the way of the world." Why? Because the king's decree was reversed, contrary to Persian law, and because Achashverosh killed almost 8,000 of his own people out of love for Esther. That does not sound like a supernatural event to me. The Magen Avraham (218:11) gives the following example as a miracle that is not in "the way of the world": a wild lion or camel attacks you and you survive.
It seems from this that even those who hold that a miracle must be out of "the way of the world" still does not define a miracle as something supernatural, which dovetails nicely with the above. (On this issue, R. Reuven Ziegler directed me to the following article by R. Gerald Blidstein: "Al Ha-Nes Ke-Musag Hilkhasi" in Da'as, 2003)
Let's close with the Mishnah Berurah's words (218:32):
Even if the salvation was not beyond nature, since he was in danger would this salvation not have appeared it is called a miracle and one is obligated to thank and praise the Creator for arranging the salvation at this time.That seems to be precisely R. Soloveitchik's point in the prior post.