ד'ה כי שדית בור בינייהו אתיא כולהו Tosfos takes issue with Rashi about how he explained that shain could be derived from bor and aish. Let us first review Rashi’s explanation. Rashi says that if the Torah wrote bor we could say; a. If bor which does not move is liable certainly shain that moves is liable. b. We would then refute the kal v’chomer by saying; you cannot compare shain to bor, for bor is initially a damager. c. We then argue; aish proves that one is liable even though it is not initially a damager. d. You cannot learn from aish because it is muod even for things that are not suitable for it, such as scorching stones. How can you derive shain from aish? Shain is muod only for food that is suitable for shain. e. Bor proves that a damager can be liable even if only for things that are suitable for it. Bor is exempt when it kills a person or destroys vessels. We see that there can be limited liability. f. From bor we see that there can be limited liability and a damager need not be liable even for things that are not suited for it. From aish we see that a damager need not be initially made as a damager. It is not the unique characteristics of bor and aish that cause them to be liable. Rather, the common characteristic, that they are likely to damage, they are your property and it is your obligation to guard them which is the reason for liability. So too, shain that shares all the common characteristics is also liable. Tosfos will show how he disagrees with Rashi on some of the steps in this derivation. Rashi explained:when discussing that shain can be derived from the common characteristics ofbor and aish (in step d), that you can refute the derivation from aish by saying: How can you compare shain to aish? Aish is muod to consume both that which is suitable for it,wood,and that which is not suitable for itstones. Can you say that shain which is muod only for that which is suitable for it, should be liable as aish is? Rashi is saying that there is a situation where shain is exempt because that which it is consuming is not suitable for it. And this is difficult: For we do not find something that is not suitable for shain. For if it ate something that is not suitable for itsuch as garments or vessels, it is not a toldoh of shain but a toldoh of keren since there is no pleasurefor the animal **from damaging it.**Furthermore, even if we did find some situationthat shain consumed something that is not suitable for it and that would not qualify as a toldoh of keren, we should learn from aish which is liable even for things that are not suitable for aish,that shain is liable even thoughthe****consumed article **is not suitable for it.**Since there is no specific exemption in the Torah that excludes non-suitable item from shain, there is every reason to believe that shain is liable even for the consumption of non-suitable items as can be seen from aish. **And it appears that shain can be derived from a half-derivation.We follow step a), b), and c). Step d) is not valid as Tosfos has just explained, thus we learn that shain is liable from a kal v’chomer from bor, when the kal v’chomer is refuted on the basis that bor is initially made to damage we defend the derivation with aish, which shows that a damager need not be initially made to damage. There is no further argument. We now know that shain is a damager. Orwe may learn shain from aish alone,in the following manner: If aish which is not alive is liable, shain which is alive should certainly be liable. There is no refutation to this kal v’chomer and we would know that shain is a damager. Upon careful analysis we se that the difference between Rashi and Tosfos on this issue is as follows: Rashi holds that we can present a refutation of a kal v’chomer from a non-existent situation, as when we refute the kal v’chomer from aish by saying that aish is liable even for things that are not suitable for aish such as stones, while shain is not. The statement is essentially true. There is no situation of shain where the shain consumes something that is not suitable for it and it is liable. However, the reason that this is so is because the situation does not exist as Tosfos taught us earlier. Rashi holds that despite the fact that the situation does not exist, this argument can be presented as a refutation of the kal v’chomer. Tosfos holds that this argument cannot be presented as a refutation although it is perfectly true, because the situation of shain consuming something that it is not suitable for it is a non-existent situation. Based on this analysis Tosfos will now offer a defense of Rashi’s explanation. However, it can be saidin ordertodefendRashi’s explanation that it is proper to present a refutation based on a situation that is non-existent in shain. For the G’moro presents this type of refutation in , in reference to a slave and a woman,where the G’moro is attempting to learn that a slave is unfit to testify from a woman.*The G’moro refutes the**attempt by saying;how can you compare a slave to a woman? **A woman is not fit for circumcision.Circumcision for women is a non-existent situation and even so it is presented as a refutation to a kal v’chomer. This seems to concur with Rashi’s position. In step e) Rashi says that bor is proof that there can be limited liability because bor is not liable for things that are not suited for it such as a person. Tosfos questions the designation of a person as not suitable for bor. Tosfos tells us three difficulties he has with Rashi’s explanation that a person is unsuitable for a bor, first: But that whichRashi explained: bor provesthat there can be limited liability because it is not muod for that which is not suitable for it such as a personis difficult for two reasons. One, because the borowner is exempt for a person, only when he dies and not when he is injured. A second difficulty: And furthermore,is it logicalthat becausebor is exempt for killing a person, we consider the person unsuitableto die in a bor? It is entirely possible that a person is suitable to be killed by a bor, and even so the Torah exempts the bor owner. Tosfos will prove that there may be an exemption for something that is suitable to be destroyed by a damager. Do we not find by aish as well an exemption for hidden items?Certainly, hidden items are suitable to be consumed by fire and even so the kindler of the fire is exempt for destroying them. It is clear that an exemption doesn’t necessarily make the object unsuitable for a particular damager. A third proof that a person is not considered unsuitable for a bor: And furthermore, later on 9b, when discussing the stringencies of an ox versus a bor the G’moro cannot find, according to R’ Yehudoh, who holds one liable for the destruction of vessels in a boranything that is unsuitable for a bor.Why not? There is the possibility of a personaccording to Rashi who considers a person unsuitable for bor. Tosfos’ conclusion: Rather, it appears that a person is also considered suitable for a bor, because he is suitable to die in the foul air, (1) however vessels, the G’moro later considers unsuitable because the foul air does not damage them. And even thoughwe find that new vessels shatter in the foul air as the G’moro says in the end of , even so, there areother vessels that are not ruined by the foul airand****those vessels are considered not suitable for the bor. Tosfos now turns to another aspect of bor. And if you ask: How can we learn aish from bor and one of the others? Howcan you compare aish to the otheravos, for the otheravosdo not combine with any other powerand that is why they are liable?Can you saythat the same ruling should applyto aish, which must combine with*the wind, which is another power? Forcombining with another power is a weaknessas can be seen fromthe G’moro that will soon ask in reference to one’s stone, knife or load: Howcan you compare them to **bor which is not combined with another power?**One’s stone, knife or load cannot be derived from a bor, because they have an inherent weakness, they damage only together with another power, the wind. Tosfos has quite adequately shown that combining with another power is an inherent weakness in a damager. If so, the question remains: how can we learn aish from any of the other avos? Aish has a weak point that none of them have, it must combine with another power, the wind. In order to find an answer to Tosfos problem we will have to take another look at the concept of a damager combining with another power. On the surface this seems to be a weakness, but perhaps there is another way of viewing it. And we can answer: that bor which is created withoutcombining with another power, is more stringent than one’s stone, knife or load that did not damage as they were moving, but only after they came to rest, and they became a bor only becausethey combined****with **another power,**the wind that brought them to the location where they would eventually damage. In this way, combining with another power is definitely a weak point. **However, aish that travels and damages at a distant place, because it combines with another power,**the wind, is more stringent than bor which does not travel and damages only in its place. In contrast to bor which is stationary, combining with another power in order to damage at a distant place is a stringent aspect of aish. Thus aish can be derived from bor. Tosfos has now told us that combining with another power can be viewed two ways. a. When comparing a stone that was blown into a public domain and came to rest, to a bor, it is a leniency, for the bor is totally the power of its owner and the stone became a bor only by combining with another power. b. When comparing aish to bor, combining with another power is a stringent characteristic because it gives the damager mobility as opposed to a bor that remains stationary. On 6a there is a discussion in the G’moro about deriving a stone that was blown away by the wind and rested in a public domain. The Gemara attempts to learn the stone from bor, and counters that the stone combined with another power while the bor did not. The G’moro then presents aish as proof that although it combines with another power it is liable. According to Tosfos explanation this is problematic. We need to show that the leniency of combining with another power to create a bor does not preclude liability, but the G’moro presents aish which is the stringent aspect of combining with another power because it gives the damager mobility. How can we prove from the stringent aspect of combining with another power as in aish, that the lenient aspect as in the case of one’s stone does not preclude liability? And that which the G’moro soon sayson 6a, when presented with the argument that the stone is the product of combined powers, aish is proofthat this does not preclude liability for aish also combines with another power and is liable.The G’moro seems to be saying that despite the weakness of being the product of combined powers aish is liable. But Tosfos said that the combined powers that make aish mobile are a stringent characteristic? What the G’moro means is as follows: even though aish combines with another power and it is considered as if it did all the damage itself, and he is liable because it is considered as if he shot an arrow, (2) so too,the stone, knife, or load, even though they combine with another powerto form a bor, it is considered as if the owner himself formed this bor without another power. Tosfos attempts another solution to this problem: Our original question was that the G’moro later presents aish to prove that although a damager consists of combined powers it is liable. This seems to be saying that the combined powers of aish are a weakness and despite the weakness there is liability. But Tosfos had said that the combined powers of aish are a stringent characteristic? Tosfos now says that this might be what the G’moro on 6a means when it refutes this proof. The G’moro’s text is: How can you compare the stone, knife and load to aish? Aish normally travels and damages. Alternatively, that isprecisely what the G’moro meant when it asks: How can you comparethe stone, knife or load to aish where the combined powers are a greater stringency, because as a result ofthe combined powers it travels and damages at a distance, which is not true of his stone, knife or loadthat damage while stationary and therefore the combined power aspect is a leniency whereas in aish it is a stringency. Tosfos will now examine yet another aspect of bor’s characteristics. And if you ask: How can we learn all the avos from aish and bor?One can refute that by arguing: How can you compare the other avos to aish and bor, theyaish and bor are circumstances of his own actions causing the damage, (3) as the G’moro explains later in reference to a bor that is rolled aboutby people and animals who kick it from place to place. The G’moro uses this argument to say that the bor that is rolled about cannot be learned from an ordinary bor because the ordinary bor is his own creation whereas the rolling bor is not. And aish as well is his own action that causes the damage for he lit the fire himself. And we can answer: That aish is not considered one’s own action causing the damage because the wind assistsin the damaging. We now understand that “his own action causing the damage” means that the damager is totally his action. A person damaging can then be thought of as his own action causing the damage, since he does it himself. And if you ask: froma combination of bor and a person how can we learn?One could ask: Howcan you compare the othersto bor and a person, they are cases of hisown action causing the damage? Tosfos conclusion is that it is true that ordinarily a person damaging is a case of one’s own action causing the damage. However, there is a case of a person damaging that is not. And we can answer: That we learnall other avosfrom bor and a sleeping person (4) or a person that fell from a roof in an uncommonlystrong wind, who is liable as the G’moro says at the end of the second chapter (27a).A sleeping person is not a case of ‘the action of the person’ causing the damage and we can learn liability for the other avos from this case. Tosfos now deals with yet another characteristic of bor. And if you ask: From bor and regel how can we learnthe other avos? One can ask: How can you comparethe other avos tobor and regel?For bor and regel damaging is a usual occurrenceas we seelater on 6b the G’moro considers bor as a usual occurrence. And we can answer: That damaging is not more of a usual occurrence for bor than for the other avos and the G’moro said that later on 6b onlyin order **to mention a stringent characteristic that is equally applicable to bor, a wall, and a tree.**The G’moro there is attempting to learn from bor that one is liable for a wall or tree that fell and damaged. The G’moro uses a “usual occurrence” as a common characteristic because that happens to be true of all of them, but not more so than other damagers.

1. Tosfos is referring to a dispute between Rav and Shmuel about the reason one is liable for bor. Rav says that it is because of the foul air produced by the bor.

1. Tosfos is referring to a G’moro later on 22a, where R’ Yochonon says that the liability for one’s fire is equivalent to the liability for shooting an arrow.
2. This is a reference to a G’moro on 6a that defines bor as one’s own action creating the damager.
3. Many Achronim question this designation of a sleeping person as not being a case of ‘his own action causing the damage’, especially in view of Tosfos’ telling us in the name of the Y’rushalmee that one is liable only when he laid down to sleep near vessels. It seems that his action of lying down near the vessels is causing the damage. See Otzar HaTosfos note 847.

[They] are forewarned. The Gemara says that keren cannot be derived from all other avos because all other avos are initially muadim. The term initially muadim indicates that they pay in full even the first time they damage while keren is first a tam and pays half the first three times it damages. Tosafot will show that we cannot accept this simple understanding of the Gemara. Later on Bava Kamma 15a there is a dispute among the amoraim about the half payment of a tam. Rav Papa says that it is a monetary requirement. This means that an ordinary ox is assumed to be a potential damager even as far as goring by keren is concerned. His owner should be aware that he needs to be guarded to prevent him from goring others. Therefore, when one fails to guard his ox he is liable for failing to fulfill his obligation to prevent his ox from damaging. Since this reality is not immediately apparent to the ox owner, the Torah was lenient with him and requires only half payment until it is actually established that his ox is a muad. Rav Huno son of R’ Yehoshua says that an ordinary ox is not a potential damager and need not be guarded. The half payment is a fine that the Torah placed upon the owner in order to encourage extra preventative measures. One should not explain that the term initially a muad refers to the rule that they pay in full as opposed to keren which pays half, for if that were so we would learn from the other avos that keren also pays full. Since it would not be written that keren pays half,¹ we would learn keren from all other avos and we would assume that it pays in full as do all other avos. Rather, Rabbeinu Tam explains that the term initially a muad refers to the fact that it is usual for them to damage, which is not true of keren, because ordinary oxen are assumed to be guardedaccording to the one who holds that half payment is a fine. Keren is not as likely to damage as are the other avos and it could therefore not be learnt from the other avos. In our Gemara the opposing opinion is presented as the one who holds that keren is more likely to be liable. According to him keren can be derived from the other avos by a kal v’chomer since he damages intentionally. Rashi says that that it is not clear who the author of this opinion is. Tosafot will inform us who he believes is the author of this opinion. And the one who says: to the contrary, keren is more likely to be liable**** because of his intent to damage, that is in accordance with the one who says half payment is a monetary payment, because it is common for oxen to damage and they are not assumed to be guarded. And not as Rashi says that the author of this opinion has not been clarified. Note: You will notice in the text of your Gemara that there are parentheses around most of the text of the Tosafot. There is a great controversy about whether this is actually a part of Tosafot. The objection to the text of this Tosafot is based primarily on Tosafot ד"ה אש, so we will wait till after we learn that Tosafot and then discuss the various opinions.

footnotes: ¹ The Gemara at this point is working under the premise that keren would not be written in the Torah and we would learn keren from bor and one of the other avos.

...Their [unique] halakhot. It appears from the Gemara that the only purpose for the Torah writing each and every one of the avos is because of the unique laws that they each have. According to Tosafot analysis the Gemara did not have to say that we would be lacking the unique laws of each of the avos. There is one general law that applies to all of the avos that would be lacking if bor was one of the source of the damagers, the liability for vessels. The Gemara could have said that each and every av had to be written explicitly, for if they were not written, rather, we would derive them from one of the others and bor, we would exempt vessels from liability by all of the avos. Since they would all be derived from bor which is exempt for damaging vessels all the other avos would also be exempt for damaging vessels. The Gemara did not have to say that writing all the avos is necessary only because of the distinctive laws of each one. Perhaps this problem about the exemption of vessels could be resolved by adding aish which is not exempt for the destruction of vessels and all of the other avos could be derived from aish and one of the others? That is why the Gemara says that all the avos needed to be written only because of their unique laws. And if we would learn all of the other avos from any one of these avos and aish, we would have to exempt hidden objects from liability by all of the avos. Adding aish would not result in a situation where the avos needed to be written only for their unique laws. There would still be a general rule that would be lacking even after the addition of aish; liability for hidden objects. The Gemara has explained why the Torah had to write all of the avos, but why is the Mishna written as it is which leads us to believe that all the avos needed to be written because otherwise we could not learn them from each other? And our Mishna taught us in the format of that leads us to believe that each and every av had to be written, otherwise we would not know of it, only to make the Torah great and beautify it. As we study the Mishna in this format we become aware of the weaknesses and strengths of each of the avos which give us a greater understanding of the avos. This greater understanding beautifies the Torah. Eventually as we study we become aware that some of the avos could have been derived from bor and one of the others, so we are ultimately not misled.

Pit to exempt for [damage to] vessels. The Gemara said that bor had to be written. It could not be derived from any of the others, since it is the only one that does not travel. Why did the Gemara say that bor was written for its unique law, the exemption of vessels? Bor had to be written because it could not be derived from the others. As the Gemara is in the mode of listing**** the special laws of the other avosit also mentions the unique law of bor. At this point in the Gemara it was not necessary to mention the special law of bor because bor cannot be derived from the other avos and definitely needed to be written in the Torah.

Fire to exempt a concealed [object]. The Gemara seems to be saying that the only reason aish had to be written in the Torah is for its unique law that when aish destroys hidden objects it is exempt. Tosafot point out that this is not the only reason aish needed to be written. The Gemara could have said that aish was written so that it should be liable for destroying vessels, because aish cannot be derived from any of the live damagers. It can only be derived from any one of the others and bor which is exempt for the destruction of vessels, aish would then also be exempt for damaging vessels. The explanation of the Gemara that aish was written to teach us the exemption of hidden objects is only one of the reasons that aish had to be written. It is apparent from this Tosafot that if aish were not explicitly written in the Torah, it could be derived from bor and aish would also be exempt for destroying vessels. According to this Tosafot the problem seems to exist only for aish, but not for the other avos. This contradicts what Tosafot says in ד"ה להלכותיהן where it seems that this problem would be true of any av derived from bor and one of the others. Tosafot said there that all of the avos would have a general exemption for damaging vessels because they would all be derived from bor while here Tosafot is saying that only aish would have the exemption for vessels not the other avos. Based on this contradiction, Maharshal deletes most of the text of that Tosafot. Maharsho defends the text: This Tosafot is saying that if we would attempt to learn any of the avos from each other, ultimately aish would be exempt for vessels. For example we could learn that regel is liable from keren and shain. Either sources are liable for vessels, thus the derivative, regel, would also be liable for vessels. However, aish could not be derived from any of the live damagers, because we have seen in the Mishna that a spirit of life is a stringent characteristic that aish does not have. It can only be derived from bor which is also not alive, but if it is derived from bor it would have the exemption for vessels. That is why our Tosafot says that the problem of the exemption for vessels is true of aish as opposed to the other avos, because aish can only be derived from bor. The other avos might each be derived from two of the other avos, where there is no exemption for vessels in either of the sources. But why does the previous Tosafot indicate that the exemption for vessels would apply to all of the avos? Maharsho explains that the previous Tosafot is discussing the particular phrase of the Gemara that says all the avos could be learned from bor and one of the others. Tosafot correctly says that if bor was one of the sources, all the other avos would be exempt for vessels. The Tosafot ד"ה אש is considering learning any one of the avos from any two of the others, this can be done without using bor as a source. Thus all the others would not have the exemption for vessels. Aish which can be derived only from bor would have the exemption for vessels.