"ותהרין שתי בנות לוט מאביהן. ותלד הבכירה בן ותקרא שמו מואב הוא אבי מואב עד היום. והצעירה גם הוא ילדה בן ותקרא שמו בן עמי הוא אבי בני עמון עד היום" (י"ט ל"ו - ל"ח).
The Virtue of Aveira Lishma
The Gemara in Nazir and Horiyos praises a transgression which is done for the sake of a Mitzva. It first praises the actions of Lot’s daughters. Subsequently the Gemara equates it to a Mitzva which was not done with the correct intention. The Gemara brings support from a verse which praises Ya’el’s relations with Sisera and equates it to certain acts of Mitzvos done by our Matriarchs which were not done with the correct intentions.
The Opinion of Rav Chaim Volozhiner and the Ramchal
It would have seemed from this Gemara that one has an open license to commit an Aveira if one has a good intention in mind. However, Rav Chaim Volozhiner flatly rejects such an interpretation. He says that if that were the case then there is no need for 613 Mitzvos. All one would need is good intentions; there would be no need for a structured list. He therefore says that once Torah was given that is the absolute rule. Only before Torah was given, and during our time to the B’nei Noach, there is permission to act in accordance to what seems to be correct, even if it’s an Aveira. What about Ya’el? To that he has two answers. Firstly that she knew and perceived deep Kabbalistic secrets pertaining to this relation. But none of us nowadays have such knowledge. Secondly, it was done to save all of Klal Yisrael.
The Ramchal has a similar opinion to Rav Chaim Volozhiner. These Gemarahs play no practical role nowadays. Ya’el’s actions were a specific ruling due to deep Kabbalistic reasoning.
Sources in Shas which seem problematic
The Mishna in Brachos would have seemed to contradict this understanding. The Mishna says that there came a point where, due to certain reasons, Ezra instituted that one should greet his friend using the name of Hashem. The Gemara bases this on a Possuk in Tehillim-עת לעשות לד' הפרו תורתך, which, when translated literally, seems to imply that at times of need one may transgress the Torah. However, this alone is not proof, because Rashi on the Mishna says that here it was permissible for them to allow such a thing even though it seems forbidden. So from this example we have no proof, because according to Rashi we aren’t dealing with something which is actually forbidden, but with a deed which seems to be a prohibition.
However, Rashi comments on the subsequent Gemara that another example of such behaviour was that which Eliyahu offered up a sacrifice outside the Beis HaMikdash. This a full transgression, but even so it was permissible. But again there is no proof, because the Gemara in Yevamos gives specific permission to a prophet to do such a thing in specific circumstances.
The one possible proof could be from the Gemara in Yuma. The Gemara says that although it is forbidden for Kohanim to benefit from their priestly garb it was permitted for Shimon HaTzaddik to go greet Alexander the Great in his garb due to the aforementioned Possuk from Tehillim.
We can answer that according to Rav Chaim Volozhiner this is not a question, because it was done in order to save the nation. It is possible that it was not only due to the great physical splendour which these garments afforded Shimon HaTzaddik which therefore were necessary to be worn. Rather, as the Yerushalmi teaches us, the eight garments of the Kohen Gadol correspond to the eight days of Milah. Since the number eight indicates something supernatural, it could be that the Bigdei Kehuna invoke a supernatural level of mercy. Be that as it may, this case cannot prove a general rule.
Sources in the Rishonim and Acharonim
The Rashba in a Teshuva wrote to his disciple not to enforce the letter of the law upon his arrival to his community. Sometimes, says the Rashba, it is preferable to turn a blind eye and eventually people will come around to the correct path. One of the sources that he quotes is the Gemara in Nazir. Apparently he held that it has practical ramifications.
The Mishna in Brachos states that the earliest time that one may read Shma at night is when the stars emerge. Tosfos therefore asks on the widespread custom to daven and read Shma earlier. The Sefer HaMichtam, dealing with this same question, says that really there is no Halachik basis for it, but there were great sages who saw it necessary to implement this practice due to the fact that if they wouldn’t say it early they wouldn’t say it at all. This was due to the fact that in those times people did not go out at night, so making a Minyan after nightfall proper was not feasible. He bases this idea on the aforementioned Gemara in Brachos 63a. Apparently the Gemara in Brachos is relevant even regarding a non-prophet.
The Rambam says that if someone on his deathbed says to give a gift to a non-Jew we do not listen to him because of the prohibition of Lo Sechoneim. However, if he says to free his slave we listen to him after his death. This is problematic because freeing a slave is also a prohibition. The Bach says that it is because it is a transgression done for the sake of a Mitzva, which the Gemara in Nazir allowed. It is a Mitzva to fulfil the will of the dead, and in addition this slave will become a fully-fledged Jew and will have many Mitzvos. Clearly, in his view the Gemara in Nazir has practical significance.
The Gemara in Brachos speaks very harshly about one who does Mitzvos with the wrong intentions. Tosfos asks that the Gemara in Pesachim says that one should always do Mitzvos, even for the wrong intentions, because eventually one will reach the level of doing for the correct reason. Tosfos answers that the difference is that when it’s in order to knock down one’s fellow that is prohibited. However, if it is because one seeks honour and the like that is permissible. However, the Maharach Ohr Zaruah says that the Gemara in Brachos, which forbids doing Mitzvos for the wrong reason, applies to all cases. The reason why it is permitted to do Mitzvos without proper intention is because of the principle of Aveira Lishma-it will lead one to do Mitzvos for the right reasons eventually. Again, we see according to him that it has practical ramifications.
The Gemara in Menachos says that it is a sin to talk in between placing the Tefillin Shel Yad and Shel Rosh and one returns from the battlefield due to it. Some opinions hold that the sin is that one caused oneself to make an extra Bracha, because now one has to make a new Bracha on the Shel Rosh. However, Rashi says that the sin is that one will forget to make a Bracha on the Shel Rosh. Why did Rashi give a new explanation? Rav Shlomo Kluger explains that Rashi held that since the new Bracha that one would make would have been with correct intentions it would be an Aveira Lishma, which, as we saw in the beginning, is as good as a Mitzva done with the wrong intentions. One certainly doesn’t go back from the battlefield for Mitzvos done with the wrong intention! Therefore, Rashi held that the sin must be due to forgetting the Bracha on the Shel Rosh. Apparently, according to him, Aveira Lishma is relevant.
A Specific Instance of Permissibility for Aveira
There are times when we are required to transgress something in order to minimise the essence of that same transgression being performed by others. Let us illustrate.
Chizkiyahu cut off the doors to the Sanctuary of the Beis HaMikdash and sent them as a token of appeasement to the king of Assyria. The Sages disagreed with this action because it is forbidden to cut off any part of the Beis HaMikdash. What was Chizkiya’s reasoning? With whom do we go in accordance?
The Mahar”i Vail was asked whether it is permitted to cut down and sell the wood from a cemetery in order to pay off the local landlord from grazing his livestock there. He replied that it is permitted in order to prevent further desecration taking place in that same cemetery. His proof is from Chizkiyahu’s actions. He cut off a part of the Beis HaMikdash in order to prevent the entire building from being destroyed by the Assyrians.
The difficulty with this position is that the Sages disagreed with Chizkiya! However, Rashi says that the Sages reasoning was based on the fact that Hashem had promised to protect Yerushalayim. Apparently they agreed to the basic reasoning.
We find a similar idea quoted by the Shulchan Aruch. The Gemara in Brachos says that it is forbidden to place a Sefer Torah on the animal that one is riding on. However, if bandits are coming and one is afraid that they will steal it one should sit on it to protect it. One may commit a relatively small desecration on a Sefer Torah if one is preventing a far greater desecration by someone else.
Another similar idea is to be found in the Shevus Ya’akov. He was asked by a certain community how to deal with their tremendous amounts of Shaimos which were being desecrated in terrible ways by non-Jews due to the fact that there was no place to put it. The Shevus Ya’akov said that it is preferable to burn the Shaimos and not to let it come to a greater desecration. Even though burning Shaimos is forbidden some say that there has to have been positive intent in the writing in order to sanctify it. Others say that printed materials in general are not sanctified. Although the Knesses Yechezkel argued on him, the Chazon Ish ruled in accordance with the Shevus Ya’akov. Again, this is similar concept as above.
Two Practical Questions
There were two very disturbing questions that I was asked, both similar in content. The first: I was called by a certain school here in Yerushalayim. The teachers found the four letter Name of Hashem written all over the bathroom. A similar question was asked to me by the municipality, which found the four letter Name written across one of the major highways. To both questions I replied that they should bring Arab workers to paint over and whitewash the areas respectively. My reasoning was as follows. Firstly, even those who say that it is forbidden to erase Hashem’s Name even when it was not written with intent would agree in this case. A name which was written in order to be disgraced certainly does not become sanctified. However, my main reason was the ruling of the Chasam Sofer in a similar case. A certain Shul had commissioned the writing of a parchment which would serve as a decorative plaque which would bear the verse זה השער לד' צדיקים יבואו בו-This is the gate for Hashem, righteous people will pass through it. An evil person came and affixed it in a bathroom in a way that it was impossible to remove. The Chasam Sofer ruled that it should be erased in order to prevent this horrifying desecration. One of his main supports is the Gemara about Aveira Lishma.
Although we have seen that there may be some Halachik implications from the principle of Aveira Lishma, one needs to be a serious Talmid Chochom in order to know how and where it will apply.
 Sefer HaMichtam Brachos 2a
 See Minchas Osher 2:55 for a full discussion of this issue.