Gemara

60b (Mishnah): One is Chayav Misah for idolatry, whether he serves, or whether he slaughters...

61b (Abaye): If one served idolatry due to love or fear, he is liable, for in any event he served.

(Rava): He is liable only if he accepted it to be his god. If not, he is exempt.

Support (Abaye, for himself - Beraisa): "Lo Sishtachaveh Lahem" (to idols), but you may bow to a person

Suggestion: Perhaps you may bow to a person that people serve (like idolatry), like Haman!

Rejection: "V'Lo So'ovdem."

People served Haman because they feared Achashverosh, and the Torah considers this idolatry!

Rejection (Rava): No. The Torah forbids bowing to a person who is served, such as Haman, but only if people truly intend to serve him, unlike Haman, who was served only out of fear.

Question: According to Abaye, we find idolatry b'Shogeg, i.e. he served due to love or fear. According to Rava, how do we find this?

Answer: He thought that idolatry is permitted.

74a (Beraisa - R. Yishmael): If one is told to serve idolatry or be killed, he transgresses - "va'Chay Bahem", do not die due to Mitzvos.

Suggestion: Perhaps this applies even in public!

Rejection: "V'Lo Sechalelu Es Shem Kodshi v'Nikdashti."

Avodah Zarah 54a (Rava): We would have thought that "V'Lo So'ovdem" forbids serving willingly or b'Ones. "Va'Chay Bahem" teaches that one does not forfeit one's life to avoid transgressing.

Contradiction: "V'Lo Sechalelu Es Shem Kodshi" - one may not transgress, even b'Ones.

Resolution: In private, "va'Chay Bahem." In public, "v'Lo Sechalelu..."

Rishonim

Rambam (Hilchos Avodah Zarah 3:5): If one excreted in front of Ba'al Pe'or, even though he intended to disgrace it, he is liable.

Rambam (6): If one served idolatry due to love, e.g. he desired an image because it was made very beautifully, or if he served due to fear, lest it do evil to him, like idolaters believe that it has power to help or harm, if he accepted it for a god, he is Chayav Misah. If he served it in the normal way, or in one of the four ways, due to love or fear, he is exempt.

Ra'avad: We explain that he served out of love or fear of a person, and not of the idolatry.

Kesef Mishneh: It is known that the Halachah follows Rava (against Abaye), so he is exempt. Even so, if he accepted it for a god he is liable, even due to love or fear, like the Gemara says. The Rambam did not explain that we discuss fear of a person, for this is Ones! The Torah exempts Ones. How could Abaye disagree?!

Question (Ramach): The Rambam says that one who excreted in front of Ba'al Pe'or is liable, even though he did not accept it to be his god and intended to disgrace it! No one else explains that we discuss love or fear of the idolatry. The primary Perush is like Tosfos says, love or fear (of people), like Haman and Nebuchadnetzar's image. According to this, it is not difficult why one who intended to disgrace it is liable.

Question (in Rivash 110): The Gemara mentioned only Avodah due to love or fear. What is the Rambam's source to include its special Avodah or the four Avodos Penim? How can he exempt Avodas Penim out of love or fear if this is not its normal Avodah? He loves it, and serves it in a superior way. This shows that he accept it to be his god!

Answer (Rivash): Rashi explains the Mishnah to say that one who excreted in front of Ba'al Pe'or is Chayav Misah, and Chayav Korban if he was Shogeg. Others explain that he is exempt, like Rava who exempts one who serves due to love or fear, and all the more so one who seeks to disgrace it! Rather, 'liable' means 'forbidden'. However, the Rambam says that he is liable and brings a Korban. The Rambam does not explain that Abaye and Rava do not discuss one who saw an image that was not served and loved it for its beauty, or feared lest it harm him, and began to serve it. All exempt for this, since he did not accept it to be his god. Rather, they argue about an idolatry that all serve due to love or fear, like Haman. Rava exempts even for the four Avodos, for people bowed to Haman. We cannot ask from Ba'al Pe'or. It was a real idolatry that people accepted for a god and served it. Even one who did not accept it is liable for serving it the way others do. However, the Meforshim explain due to love or fear unlike the Rambam. If one serves because he thinks that it has power to harm or help, he is liable, even if he did not accept it for a god. Most idolaters think that there is a G-d above their idolatry, just they think that their idolatry has power to harm or help, or that this is the Creator's will. Surely the Torah forbids such Avodah! Abaye and Rava argue only about an idolatry that all agree that it has no power. We do not discuss one who serves due to a mortal threat. Even though one should be Moser Nefesh, if he was not, there is no Misah, lashes or Kares, for he was Anus. Haman was not a case of mortal danger. Abaye obligates, for he serves willingly. Or, with difficulty we can give another answer for the Rambam. It is more reasonable to exempt Avodah due to love or fear without accepting it for a god, for this is like Ones, than one who intends to disgrace, for its followers think that it desires the disgrace. The Rambam says that he is liable, i.e. Korban, but not Misah or Kares, for the person errs (and thinks that he disgraces it).

Kesef Mishneh: The Rambam holds like this latter answer.

Note: Perhaps this is because the Rambam says that those who serve due to love or fear think that it has power to harm or help.

Tosfos (61b DH Rava): Rava exempts one who serves idolatry due to love or fear. One must be Moser Nefesh rather than serve, but we can say that even so, if he was not Moser Nefesh, he is not Chayav Misah. Do not say that Rava exempts because he holds (Avodah Zarah 54a) that one need not be Moser Nefesh for idolatry in private. If so, when we challenged Rava from Beraisos, we could have answered that those Tana'im obligate Mesiras Nefesh for idolatry in private, and Rava holds like the Tana who exempts (74a)! Some obligate Mesiras Nefesh for a regular Avodah Zarah, but here we discuss an idolatry that everyone serves due to love or fear, like Haman, which the Sugya brings. The Mishnah (whether he serves...) connotes such an idolatry. We would not need this to teach about a regular idolatry, for the Seifa obligates for excreting in front of Ba'al Pe'or, even though he intends to disgrace it. According to Rava, why didn't Mordechai bow to Haman? The Medrash says that he had idols on his heart. The Yerushalmi says that he refused, in order to fulfill Kidush Hash-m.

Poskim

Shulchan Aruch (YD 119:9): If a convert reverted to idolatry due to fear, or if a Yisrael sinned due to fear lest he be killed, he is a full Yisrael. What he slaughters is permitted, and he does not forbid wine that he touches.

Gra (23): The Halachah follows Rava, that one who served idolatry due to fear is exempt. He is not even lashed.

Shulchan Aruch (11): If in one city Ploni is an idolater in front of idolaters, and in another city he enters a Yisrael's house and says that he is a Yisrael, he does not make (wine that he touches) Yayin Nesech.

Rashba (7:179, citing R. Yonah, cited in Beis Yosef DH Od): If in one city Ploni believes in idolatry in front of Nochrim, and in another city he enters a Yisrael's house and says that he is a Yisrael, and we do not know, since he tells us that he is a Yisrael, he does not make Yayin Nesech. This is because presumably, idolatry is Sheker. He says that he believes in it only to please his Yetzer ha'Ra. He does not believe it in his heart. When he says that he is a Yisrael, this is with a full heart. He has a straight, proper Emunah.

Shach (24): He does not make Yayin Nesech, for he is truly a Yisrael. Obviously, he is not believed about Isurim, for he serves idolatry.

Pischei Teshuvah (2): The Pri To'ar says that this is only if he gets no benefit from saying that he is a Yisrael.

Noda b'Yehudah (2 EH 80): A case occurred in which a man came to a city, married a woman, then fled to his former residence. It was found that he is a Mumar with a Nochris wife. One opinion ignores a Mumar's Kidushin, but we may not be lenient here. This man acted like a Yisrael for three weeks. Perhaps he repented! The fact that he later returned to his old ways does not show that he had not repented. An idolater in one city who acts like a Yisrael in another city does not make Yayin Nesech. The Pri Toar says that this is only when he gets no benefit from saying that he is a Yisrael. Perhaps this is wrong. Even if it is correct, this is to be stringent and forbid wine, but not to permit a married woman.