The back story TB Sanhedrin 68

To better understand the context of today’s story on daf TB Sanhedrin 68, let me give you the back story. Rabbi Eliezer was a strong headed man. He and the sages argued about the ritual readiness of the oven of akhnai. Although he used heavenly proofs to prove his position, the sages disagreed and voted against him. Because he would not accept that democratic vote, the sages excommunicated him. Nevertheless when he was on his deathbed, the rabbis had to visit such a great Sage, but keep their distance.

 “When Rabbi Eliezer took ill, Rabbi Akiva and his colleagues came to visit him. He was sitting on his canopied bed [bekinof ], and they were sitting in his parlor [biteraklin]; they did not know if he would be able to receive them, due to his illness.

“And that day was Shabbat eve, and Rabbi Eliezer’s son Hyrcanus entered to remove his phylacteries, as phylacteries are not worn on Shabbat. His father berated him, and he left reprimanded. Hyrcanus said to his father’s colleagues: It appears to me that father went insane, since he berated me for no reason. Rabbi Eliezer heard this and said to them: He, Hyrcanus, and his mother went insane. How can they neglect Shabbat preparations with regard to prohibitions punishable by stoning, such as lighting the candles and preparing hot food, and engage in preparations concerning prohibitions by rabbinic decree, such as wearing phylacteries on Shabbat. 

"Since the Sages perceived from this retort that his mind was stable, they entered and sat before him at a distance of four cubits, as he was ostracized (see Bava Metzia 59b). It is forbidden to sit within four cubits of an ostracized person.

'“Rabbi Eliezer said to them: Why have you come? They said to him: We have come to study Torah, as they did not want to say that they came to visit him due to his illness. Rabbi Eliezer said to them: And why have you not come until now? They said to him: We did not have spare time. Rabbi Eliezer said to them: I would be surprised if these Sages die their own death, i.e., a natural death. Rather, they will be tortured to death by the Romans. Rabbi Akiva said to him: How will my death come about? Rabbi Eliezer said to him: Your death will be worse than theirs, as you were my primary student and you did not come to study.

 

“Rabbi Eliezer raised his two arms and placed them on his heart, and he said: Woe to you, my two arms, as they are like two Torah scrolls that are now being rolled up, and will never be opened again. I have learned much Torah, and I have taught much Torah. I have learned much Torah, and I have not taken away from my teachers, i.e., I have not received from their wisdom, even like a dog lapping from the sea. I have taught much Torah, and my students have taken away from me, i.e., they have received from my wisdom, only like the tiny amount that a paintbrush removes from a tube of paint.

 "Moreover, I can teach three hundred halakhot with regard to a snow-white leprous mark [bebaheret], but no person has ever asked me anything about them. He could not find a student who could fully understand him in those matters. Moreover, I can teach three hundred halakhot, and some say that Rabbi Eliezer said three thousand halakhot, with regard to the planting of cucumbers by sorcery, but no person has ever asked me anything about them, besides Akiva ben Yosef.

“Rabbi Eliezer described the incident: Once he and I were walking along the way, and he said to me: My teacher, teach me about the planting of cucumbers. I said one statement of sorcery, and the entire field became filled with cucumbers. He said to me: My teacher, you have taught me about planting them; teach me about uprooting them. I said one statement and they all were gathered to one place.

“After these comments, the Sages asked him questions of halakha: What is the halakha, with regard to ritual impurity, of a ball made of leather and stuffed with rags, and likewise a last, the frame on which a shoe is fashioned, which is made of leather and stuffed with rags, and likewise an amulet wrapped in leather, and a pouch for pearls, wrapped in leather, and a small weight, which is wrapped in leather? Rabbi Eliezer said to them: They are susceptible to impurity, and their purification is effected by immersing them in a ritual bath as they are, as there is no need to open them up.

“They asked him further: What is the halakha with regard to a shoe that is on a last? Is it considered a complete vessel, which needs no further preparation, and is therefore susceptible to impurity? Rabbi Eliezer said to them: It is pure, and with this word, his soul left him in purity. Rabbi Yehoshua stood on his feet and said: The vow is permitted; the vow is permitted; i.e., the ostracism that was placed on Rabbi Eliezer is removed.

“Rabbi Akiva was not present at the time of his death. At the conclusion of Shabbat, Rabbi Akiva encountered the funeral procession on his way from Caesarea to Lod. Rabbi Akiva was striking his flesh in terrible anguish and regret until his blood flowed to the earth. He began to eulogize Rabbi Eliezer in the row of those comforting the mourners, and said: “My father, my father, the chariot of Israel and its horsemen” (II Kings 2:12). I have many coins, but I do not have a money changer to whom to give them, i.e., I have many questions, but after your death I have no one who can answer them” (Sefaria.org translation)

The Gemara asks the question if sorcery is forbidden, how could Rabbi Eliezer demonstrate the black arts to Rabbi Akiva?!

“The Gemara asks: How could Rabbi Eliezer have performed that act of sorcery? But didn’t we learn in the mishna that one who performs an act of sorcery is liable? The Gemara answers: Performing sorcery not in order to use it, but in order to teach oneself the halakhot is different, and it is permitted; as the Master says that it is derived from the verse: “You shall not learn to do like the abominations of those nations. There shall not be found among you…one who uses divination, a soothsayer, an enchanter, or a sorcerer” (Deuteronomy 18:9–10), so that you shall not learn, i.e., it is prohibited for you to learn, in order to do, but you may learn, i.e., it is permitted for you to learn, in order to understand the matter yourself and teach it to others.” (Sefaria.org translation)  

If a judge is to adjudicate the case of sorcery, he better know exactly what it is and how to do it. Consequently, learning the black arts is essential lest through lack of knowledge a miscarriage of justice happens and an innocent person is put to death.