The Nature of Lifnei Iver
The gemara in Mo’ed Katan (17) indicts a father who physically strikes his teenage son as having violated the prohibition of lifnei iver lo titen mikhshol. Recognizing his son’s independent-minded attitude, he should have anticipated that his son would illegally strike him back, thereby committing an aveira. By facilitating this aveira, the father has violated lifnei iver. The simple reading of this gemara implies that lifnei iver has been violated even before the son actually strikes his father. The very enabling of a situation that will likely yield an aveira constitutes lifnei iver.
By contrast, the gemara in Avoda Zara (15) presents a different picture. The gemara describes Rava having sold wine to a gentile, thereby creating a potential for idolatrous libations. This scenario is a classic case of lifnei iver; as selling wine to a gentile will enable him to violate a prohibition. Rava chased the gentile to retrieve the wine, presumably to eliminate any lifnei iver concerns. This gemara implies that lifnei iver is violated only if and when the ultimate enabled sin is violated; until then, Rava was trying to avoid a violation of lifnei iver.
The question of whether lifnei iver is immediately violated or violated only once the ultimate aveira is performed, is the subject of a debate among the Acharonim. Presumably, this technical debate reflects a larger question about how to understand the prohibition of lifnei iver. Perhaps lifnei iver is forbidden because it contributes to the ultimate sin; by facilitating the sin, the enabler is participating in the aveira. From this perspective, lifnei iver should only apply when the sin is actually perpetrated. However, the language of the pasuk – which literally prohibits placing a stumbling block before the blind – implies that the violation of lifnei iver entails merely creating a halakhic hazard - a mikhshol. The mere creating of a potential halakhic hazard is forbidden, even no one actually “stumbles” and the aveira is never realized. Thus, the question is: Is lifnei iver forbidden because of the contribution to the ultimate aveira or based on the very creation of a halakhic hazard?
This question has potential implications for a range of lifnei iver scenarios.
Classically, lifnei iver does not apply if the sinner can execute the sin without the help of the accomplice. This situation – referred to as “chad ibra nahara” (literally, one side of the river) – is based on the case of a nazir who already has easy access to wine in his close proximity (the same side of the river). By offering him wine, the wine-handler has not facilitated a sin, since wine is easily available without his contribution. The wine-handler doesn’t violate lifnei iver in this scenario.
What about a case of an interactive sin that requires two parties? Does an interactive participant violate lifnei iver if the other party could have easily located an alternate? For example, the gemara in Bava Metzia (75) discusses the prohibition of lifnei iver for a lender and borrower of a loan that allows interest payments. Each participant in this loan is assisting his counterpart in the violation of the prohibition of ribit, and therefore violates lifnei iver (as well as ribit proper). What would happen if, for example, the lender can find an alternate borrower to absorb interest payments? Would the actual borrower still violate lifnei iver? On the one hand, the participant is not creating a halakhic hazard, since the lender has ample opportunity and desire to violate the prohibition - the hazard already exists! However, if lifnei iver constitutes contribution to the ultimate sin, the borrower has directly contributed to the sin in a more intense manner than merely serving wine to a nazir. The Mishna Le-Melech (Malveh Ve-Loveh 4:2) does, in fact, incriminate the borrower for lifnei iver, whereas the Teshuvot Pnei Moshe (2:105) acquits him. It is quite possible that they are debating the nature of lifnei iver.
A third issue which may be impacted is the level of direct causality necessary to implicate someone for lifnei iver. Providing food directly to someone who can then violate a prohibition is a classic form of lifnei iver. What about providing food to a buyer who then may sell it to someone else who will violate a prohibition? This second degree lifnei iver, referred to as “lifnei de-lifnei” (enabling the enabler), is permissible according to the gemara in Avoda Zara (14). The simplest manner of explaining this exception is that the food deliverer has not created a hazard, since the first recipient will not (and cannot) violate an aveira. That hazard is created by the first purchaser, who then sells to someone who can potentially violate an issur.
The Rashba, however, claims that lifnei de-lifnei is permissible only because it is unlikely that the first recipient will then transfer the dangerous item to the person who can potentially perform the aveira. In situations that are highly likely to unfold into an aveira, lifnei iver has indeed been violated. For example, a Jew may not sell chunks of meat containing gid ha-nasheh to a gentile supplier in a city in which Jews normally purchase meats form gentile suppliers. Even though the initial Jewish seller did not deliver meat directly to the subsequent Jewish buyer, he still violates lifnei iver. Although this case constitutes lifnei de-lifnei, since it is likely that the second sale will occur, lifnei iver has been violated. According to the Rashba, fundamentally lifnei d’lifnei is forbidden provided the aveira is likely to occur. Even though the original Jewish seller didn’t create a halakhic hazard he has directly contributed to the aveira!
The question regarding the essence of lifnei iver may also affect the dynamics of other manifestation of lifnei iver. The gemara focuses primarily upon facilitating an aveira as an expression of lifnei iver. However, intentionally providing harmful or damaging advice (eitza she-eina hogenet) also constitutes lifnei iver. Are these two manifestations similar, or is lifnei iver an example of one mitzva that generates completely distinct halakhic categories? This question may impact whether the prohibition of harmful advice applies in a case of potential gentile victims. The classic prohibition of lifnei iver, forbidding the creation of an opportunity to sin, clearly applies when the other party is a gentile. If the two manifestations are similar, the application to gentiles in one domain may determine its extension in the second and related one. If the two tracks are completely distinct, however, we possibly might extend the aveira-enabling element of lifnei iver to gentiles without extending the autonomous and different prohibition of harmful advice component to gentiles. This question is debated by the Sefer Ha-Chinukh (232), who does not extend the issur of provision of harmful advice to gentile victims, and the Minchat Chinukh, who questions this limitation. According to the Minchat Chinukh, if the aveira-enabling component applies to gentile victims, the prohibition of harmful advice component should as well.
Presumably, the relationship between the two lifnei iver components depends on the nature of the classic form of lifnei iver – aveira-enabling. If this form is prohibited because the aveira is being assisted and the enabler contributes to the eventual aveira, there is little similarity between this form of lifnei iver and providing damaging advice, as in the latter case, no aveira occurs. If, however, lifnei iver and enabling an aveira is prohibited because a halakhic hazard has been created (even in the absence of the ultimate aveira), there is commonality between creating a halakhic hazard and creating a personal hazard by offering harmful advice.
An additional offshoot of this question regarding the interaction between the two tracks of lifnei iver may concern the applicability of classic lifnei iver in the case of enabling a Rabbinic prohibition. If lifnei iver is defined as enabling an aveira, it would be legitimate to question whether enabling an issur de-rabbanan is severe enough to qualify as lifnei iver. If, however, enabling an aveira is forbidden just as providing harmful advice, as one has created a menace or a vulnerability, it would be more difficult to distinguish between a vulnerability to Biblical prohibition and a vulnerability to a Rabbinic one. Just as providing general harmful advice is forbidden, providing halakhically-entangling advice is problematic, whether the entanglement concerns a Biblical or a Rabbinic concern.
Yet a third interesting offshoot of the question of the interaction between the two tracks of lifnei iver surrounds the classification of lifnei iver as a lav she-bekhlalot, a prohibition containing many subcategories. Whenever a Torah prohibition generates multiple distinct prohibitions, no malkot are administered for violation. The classic example concerns the prohibitions associated with the pasuk, “Lo tochlu al ha-dam” (Vayikra 19:26), which yields multiple prohibitions. One prohibition concerns eating animal flesh prior to the animal’s death, a second prohibition forbids eating korban meat before the zerikat ha-dam, and a third limitation imposes a fast day requirement on judges on the day of administering a halakhic execution. This one pasuk generates multiple and unrelated halakhot and is thus defined as lav she-bekhlalot, which is exempt from malkot.
The Rambam (Sefer Ha-Mitzvot, shoresh 9) claims that lifnei iver is also a lav she-bekhlalot, since it generates multiple different prohibitions. Since this one pasuk generates a prohibition to assist an aveira as well as a separate prohibition against providing harmful advice, it is considered a lav she-bekhlalot and does not yield malkot. Presumably, the Rambam viewed the two branches of lifnei iver as distinct; had he viewed them as integrated, perhaps lifnei iver would not be classified as a lav she-bekhlalot. Perhaps this view of lifnei iver is based on defining the classic lifnei iver as aveira-enabling, and therefore unrelated to the component of delivering harmful advice.