Bava Metzia 46

Rav Shach (laws of marriage 1:2)holds that there are only two types of exchange, equal to equal, or acquisition by a handkerchief. [To Rav Shach exchange of a needle for a suit of armor is equal to equal since this one wants a needle and the other wants a suit of armor.] Rav Shach holds the exchange is applicable to marrying a woman, not the acquisition by a handkerchief. ([This is like the Tosphot R'id who holds acquisition by handkerchief that is worth more that a pruta can acquire a wife.])According to this, we must say that when Rav Nachman said in Bava Metzia 46 and Kidushin 28b that fruit can not make an exchange, he must mean it cannot create an exchange but that it can be acquired by exchange. To make my comment here clear let me bring a few points. First Rav Shach is only talking about the approach of the Rambam. Clearly, Tosphot and Rabbainu Tam are utterly different. Also, we know the law is like Rav Nachman that fruit can not make an exchange, but rather only vessels. (Rambam laws of sale chapter 13) But what is a vessel? To Tosphot, a vessel is anything that can be used. But to Rav Shach this must mean that which can create an acquisition, not that which can be acquired because he holds a woman can be acquired by exchange of equal to equal. This approach of Rav Shach I must mention is not like Tosphot that there is exchange equal to equal, and a different kind that is not equal to equal, but is still not acquisition by handkerchief nor shoe. It might help to understand what Rav Shach is saying if I mention the clarification of Shmuel Rozovski that the issue is if something causes a acquisition as in the case of acquisition by a handkerchief, or if there is no object causing the transition at all. Simply in the exchange one acquires the object of the other person, and the other acquires the object of the first person. Still even with this clarification it is odd that acquisition by handkerchief would not work to marry a wife even though it is absolutely acquisition by money while acquisition by pure exchange would acquire a woman though it is a different kind of acquisition. (Later note.) I see now that Rav Shach learns the idea of exchange different than Rav Shmuel Rosovsky. He says that the approach of the Rambam is that exchange equal value for equal value is still like an acquisition by money in which the first object tat is picked up is what causes the second object to be acquired and therefore there is no question about the approach of Rav Shach. He explains this all clearly in the beginning of laws of marriage After writing the above, it occurred to me that in fact this is open in the Rambam himself. In the beginning of chapter five in laws of sale he holds that fruit can be acquired by exchange equal for equal just like Rabbainu Tam. So, when he holds like Rav Nachman that “fruit cannot make exchange,” that has to mean it cannot cause an acquisition of exchange, but they can be acquired by exchange. The question I have on this approach of the Rambam is that it does not seem to fit with the Gemara. the Gemara itself is talking always about being acquired by exchange and never once mentions causing an acquisition of exchange. So, from where would the Rambam have derived his approach?It occurred to me that the rambam understands the entire gemara as referring to causing acquisition by exchange[The difference is that causing acquisition is a subset of being able to be acquired by acquisition. This is like the fact that exchange of money does not cause acquisition. Only pulling or picking up can cause acquisition. Therefore, we see the Rambam understands the Gemara to be referring to causing acquisition.] However, I might mention that this issue is a debate between Tosphot and the Rambam because Tosphot makes a point of showing how the whole subject is referring to the ability to be acquired by exchange. He explains that the Mishna that sounds like it means causing acquisition of a coin by means of exchange of an object means that a coin can never be acquired by exchange. It can only be acquired by a sale. If one exchanges an object for the money of another, that money is not acquired. It can only be acquired if it is used to buy the object. I might mention here that Rashi and Tosphot learn the argument between Rav Nachman and Rav Sheshet differently than the Rambam. So far I have been saying according to the Rambam, the law of Rav Nachman is that fruit can be acquired by exchange, but can not make exchange; while to Rav Sheshet they can also cause exchange. According to Rashi, they differ in this. Rav Sheshet holds all movable objects can be acquired by exchange and cause it also. to Rav Nachman only vessels, that can be used can be acquired by exchange .and cause exchange. To Rashi, a ox or cow are considered to be included in movable objects. Rav Nachman mean to exclude only fruit in what can not cause exchange, but besides that, all movable objects can cause exchange, or maybe only usable vessels. However, the Rambam writes, ” One can exchange vessels for vessels, an animal for an animal, even a needle for a coat of armor or a sheep for a horse, but if he exchanges fruit for fruit , that can have the law of cheating applied to it.” (If the exchange was more than a fifth of its value, the exchange is nullified). Is a sheep usable like a vessel or like other movable objects? I mean to say he might mean that only vessels can cause exchange and he might hold thanot a sheep is included, or perhaps he means all movable objects besides can cause exchange but just not fruit? now i would like to add here that ------------------------------------------------------------------------------------------------------------------------------------- [laws of marriage 1:2] holds that there are only two types of exchange, equal to equal, or acquisition by a handkerchief. [To רב שךexchange of a needle for a שריון is equal to equal since this one wants a needle and the other wants a suit of שריון.] רב שךholds the exchange is applicable to marrying a woman, not the acquisition by a handkerchief. According to this, we must say that when רב נחמן said in בבא מציעא מ''ו ע''ב and קידושין כ''ח ע''ב that fruit can not make an exchange, he must mean it cannot create an exchange but that it can be acquired by exchange. To make my comment here clear let me bring a few points. First רב שךis only talking about the approach of the רמב''ם. Clearly, תוספות and רבינו תם are utterly different. Also, we know the law is like רב נחמן that fruit can not make an exchange, but rather only vessels. But what is a vessel? To תוספות, a vessel is anything that can be used. But to רב שך this must mean that which can create an acquisition, not that which can be acquired because he holds a woman can be acquired by exchange of equal to equal. This approach of רב שךI must mention is not like תוספות that there is exchange equal to equal, and a different kind that is not equal to equal, but is still not acquisition by handkerchief nor shoe. After writing the above, it occurred to me that in fact this is open in the רמב''ם himself. In the beginning of chapter five in הלכות מכירה he holds that fruit can be acquired by exchange equal for equal just like ר' תם. So, when he holds like רב נחמן that “fruit cannot make exchange,” that has to mean it cannot cause an acquisition of exchange, but they can be acquired bהThe question I have on this approach of the רמב''ם is that it does not seem to fit with the גמרא. Theגמרא itself is talking always about being acquired by exchange and never once mentions causing an acquisition of exchange. So, from where would the רמב''ם have derived his approach?y exchange. [The difference is that causing acquisition is a subset of being able to be acquired by acquisition. This is like the fact that exchange of money does not cause acquisition. Only pulling or picking up can cause acquisition. Therefore, we see the רמב''ם understands the גמרא to be referring to causing acquisition. However, I might mention that this issue is a debate between תוספות and the רמב''ם because תוספות makes a point of showing how the whole subject is referring to the ability to be acquired by exchange. He explains that the משנהthat sounds like it means causing acquisition of a coin by means of exchange of an object means that a coin can never be acquired by exchange. It can only be acquired by a sale. If one exchanges an object for the money of another, that money is not acquired. It can only be acquired if it is used to buy the object.---------I might mention here that רש''יand תוספות learn the argument between רב נחמן and רב ששתdifferently than the רמב''ם. So far I have been saying according to the רמב''ם , the law of רב נחמן is that fruit can be acquired by exchange, but can not make exchange; while to רב ששת they can also cause exchange. According to רש''י they differ in this. רב ששת holds all movable objects can be acquired by exchange and cause it also. to רב נחמן only vessels, that can be used can be acquired by exchange .and cause exchange. To רש''י , a ox or cow are considered to be included in movable objects. רב נחמן meant to exclude only fruit in what can not cause exchange, but besides that, all movable objects can cause exchange, or maybe only usable vessels. He writes, ” One can exchange vessels for vessels, an animal for an animal, even a needle for a coat of armor or a sheep for a horse, but if he exchanges fruit for fruit , that can have the law of cheating applied to it.” (If the exchange was more than a fifth of its value, the exchange is nullified). Is a sheep usable like a vessel or like other movable objects? I mean to say he might mean that only vessels can cause exchange and he might hold that a sheep is included, or perhaps he means all movable objects besides can cause exchange but just not fruit?