QUESTION: The Gemara inquires what the law is in a case of "Yachol" and "Eino Yachol," where two people do a Melachah together, and one of them is able to do the Melachah by himself and the other is unable to do it by himself. The Gemara suggests that perhaps the "Yachol" is Chayav.

RASHI (DH Ein Bo) implies that one possibility is that the "Yachol" is exempt and the "Eino Yachol" is Chayav. Why, though, is that a possibility? Since the Melachah is done primarily by the "Yachol," why should he not be Chayav?

(a) TOSFOS follows the logic that there is more reason for the "Yachol" to be Chayav than for the "Eino Yachol" to be Chayav, and therefore he understands the Gemara's question differently. According to Tosfos, the Gemara's question is whether the "Yachol" alone is Chayav, or whether both of them are Chayav.

(b) RASHI, however, is consistent with his reasoning earlier (92b). Rashi there explains that when the Melachah is performed by two people who are each able to do the Melachah alone, they are exempt, because it is not the normal manner to do a Melachah with someone else. In this case, too, it is logical to suggest that the "Yachol" is exempt because he is doing the Melachah in an unusual manner (that is, with someone else).

The Ritva suggests another way to understand the comment of Rashi, based on the words of Rabeinu Moshe ben Rabeinu Yitzchak that he quotes earlier (see Insights to 92:2:c). The Ritva explains that perhaps the "Yachol" is exempt because he could have done the Melachah with all of his strength had he done the Melachah alone, but now that he did the Melachah with a second person, he did it with only part of his strength. Since he did not use all of his strength, he is exempt.

QUESTION: The Gemara says that when a horse stands on four garments, with one garment under each leg, each garment is Tahor because the horse could stand on three legs while the fourth leg is only Mesaye'a. RASHI (DH Mipnei she'Yecholah) points out that this ruling follows the view of Rebbi Yehudah, who says that in a case of "Yachol" and "Yachol," where both individuals are able to do the Melachah by themselves, they are exempt because of Mesaye'a.

Why does Rashi equate "Yachol" and "Yachol" with "Yachol" and "Eino Yachol," and say that the Gemara's ruling follows Rebbi Yehudah? Even Rebbi Meir agrees that in the case of "Yachol" and "Eino Yachol," the "Eino Yachol" is exempt, and thus even Rebbi Meir agrees that Mesaye'a is exempt.

Furthermore, why does Rashi say that according to Rebbi Yehudah, "Yachol" and "Yachol" are exempt because they are both Mesaye'a? Earlier (92b), Rashi explains that the reason why "Yachol" and "Yachol" are exempt is because when two capable people perform a Melachah together, they do not perform the Melachah in the normal manner!

Finally, if Rebbi Yehudah maintains that they are exempt because "Mesaye'a Ein Bo Mamash" (one who is unable to do the Melachah by himself and merely assists someone else who is able to do it by himself is not considered to have done any Melachah), then why does the Gemara need to search for proofs from cases of Zavim to show that "Mesaye'a Ein Bo Mamash"? The Gemara should simply prove it from Rebbi Yehudah's opinion!

ANSWER: The CHASAM SOFER explains that the Gemara is in doubt whether one who is Mesaye'a is considered as though he performs the Melachah or not. The Gemara initially questions which participant in the Melachah, in a case of "Yachol" and "Eino Yachol," is exempt. One option, according to Rashi, is that the "Yachol" is exempt, and the "Eino Yachol" is Chayav. What, though, is the logic to suggest such a thing? The logic is that since a "Yachol" who does a Melachah with someone else is not doing it in the manner in which he normally does the Melachah, he is exempt. In contrast, the "Eino Yachol" who performs the Melachah with someone else is doing the Melachah in his normal manner (see previous Insight). If this logic is correct, however, then what is the logic to suggest the other possibility -- that the "Eino Yachol" is exempt and the "Yachol" is Chayav? The logic is that "Mesaye'a Ein Bo Mamash," and thus the "Eino Yachol" is exempt.

It follows that the question of whether one who is Mesaye'a is considered as though he does a significant act or not depends on Rebbi Yehudah's reasoning to exempt the two parties in the case of "Yachol" and "Yachol." If his reasoning is -- as Rashi initially explained -- that they are doing a Melachah in an abnormal manner, then in the case of "Yachol" and "Eino Yachol," the "Eino Yachol" will be Chayav, because he is doing the Melachah in his normal manner (that is, with someone else). If Rebbi Yehudah's reasoning to exempt "Yachol" and "Yachol" is because they are both considered Mesaye'a, then the "Eino Yachol" will be exempt because of Mesaye'a.

Rashi earlier explains the reasoning of Rebbi Yehudah in the first way (that the exemption is based on the fact that the two people are doing the Melachah in an abnormal manner), because there Rashi addresses the initial assumption of the Gemara (before the Gemara proposed that Mesaye'a is not significant). In the conclusion, when the Gemara teaches that the act of one who is Mesaye'a is not significant, Rashi writes this is also the actual reasoning of Rebbi Yehudah. (See also MAHARSHA.)

OPINIONS: A fundamental argument with regard to the liability for performing Melachah on Shabbos concerns a Melachah she'Einah Tzerichah l'Gufah, "a Melachah that is not needed for itself." Rebbi Yehudah and Rebbi Shimon argue whether one is Chayav for performing such a Melachah "that is not needed for itself." Rebbi Yehudah says that one is Chayav, and Rebbi Shimon says that one is Patur. What exactly is the definition of a Melachah "that is not needed for itself"?

(a) TOSFOS (94a, DH Rebbi Shimon Poter) understands that Rashi's intention is to say that a Melachah she'Einah Tzerichah l'Gufah refers to any Melachah that one does in order to prevent something else from happening, or in order to rectify something that was already done wrong. For example, a person who carries a dead body out of a house is interested in correcting an uncomfortable situation (the dead body's presence in his house), and he would have preferred that the dead body not have been brought into his house in the first place. However, Tosfos refutes this explanation. When a curtain has a wormhole and one tears some of the curtain above and below the hole in order to mend it neatly, he is Chayav (this is the Melachah of Kore'a, Shabbos 75a). Tosfos asks that according to Rashi, the one who tears the curtain should be Patur, because he tore the curtain only to prevent further damage, and he would have preferred that the wormhole not have been there in the first place!

(b) TOSFOS (94a, DH Rebbi Shimon) defines a Melachah she'Einah Tzerichah l'Gufah as any Melachah that is not performed for the same reason that that Melachah was performed in the Mishkan.

(c) The RAMBAN (94b) and BA'AL HA'ME'OR (106a) write that a Melachah must be performed with the objective for which that activity is normally performed. If one does the Melachah for a purpose other than its normal objective, it is a Melachah she'Einah Tzerichah l'Gufah. For example, digging a pit in order to use the dirt is a Melachah that is not needed for itself, because, normally, the objective of digging is in order to have a pit, and not to use the dirt, which is a secondary outcome of the digging. Also, a Melachah performed in order to prevent damage from happening, such as capturing a snake, is considered a Melachah that is not needed for itself because the normal objective of capturing is to use the animal. The same applies to carrying an object to Reshus ha'Rabim in order to keep one's body from becoming soiled (as in the case of the Kis of the Zav (11b)).

This may be Rashi's opinion as well, unlike Tosfos' understanding of Rashi (as in (b) above). This is why ripping the garment to repair a wormhole is considered a genuine Melachah -- the person ripping the garment is presently interested in having the garment ripped apart (the primary effect of the Melachah) and not in a secondary outcome of the ripping.