Klalei HaPoskim

Overview

In order to be privy to the nuances and mindsets of the Poskim, it is advantageous to understand the Klalim relevant to the Poskim, from the two Talmuds through the Rishonim to the Shulchan Aruch. The Machon Yerushalayim edition of the Yad Malachi is particularly helpful for this, as the Yad Malachi is fantastic for collecting all the ideas mentioned throughout Halachic literature and the Matnat Yado footnotes add many additional sources from those who came before and after him, as well as direct quotations of sources.

Safrut Chazal: Talmud Bavli and Yerushalmi, Tosefta, Midrashim, and Zohar

Bavli

1. Regarding intra-Talmudic Halachic decision making (Klalei HaShas), see Klalei HaTalmud (Talmudic Methodology).
2. "Sugya veDuchteh Adifah" - The Amoraim focused most on the precise presentation of the Halacha when discussing it in its proper context. When discussing tangential points, the they were not as careful to speak with complete precision satisfactory for inferring the Halacha from.

Differences Between the Yerushalmi and Bavli

1. Since the Talmud Bavli was written after the Talmud Yerushalmi, its codifiers were able to filter out the points they didn't think were accepted. As such, when the two contradict, we follow the Talmud Bavli, and some say we should never even be concerned for the Yerushalmi's statements altogether for this reason.
2. The Halacha follows the Bavli over the Yerushalmi wherever they disagree, but, if the Yerushalmi discusses a Halacha not mentioned in the Bavli, the Halacha follows the Yerushalmi. If it's a distinction not mentioned in the Bavli, then there's a strong argument to say the Bavli's omission is an indication of disagreement.
3. The Rosh writes how we only follow the Bavli over the Yerushalmi with respect to Halachot, such as Tuma veTaharah, Issur veHetter, Chiyuv and Pettur, but not things that are Tzorech Hashaah and have no ramifications on Dinei HaTorah. Those are subjective to the time, place, and needs of the people. Similarly, the Rashbesh says that with respect to Minhagim, we would follow the Yerushalmi.
4. If two approaches are offered in the Bavli and only one of them appears in the Yerushalmi, the Halacha follows that approach.
5. The Rishonim observe that the Yerushalmi in our possession is corrupt and enigmatic. At most, one person in a generation can crack its meaning. If a Baraita is quoted slightly differently in the Bavli from the way it's quoted in the Yerushalmi, the Ohr HaChaim claims one can accept the Yerushalmi's version and label the Baraita in the Bavli as Meshabeshta (corrupt). The Yad Malachi takes issue with this approach, in light of the general issue of textual obstacles in reading the Yerushalmi and the Tashbetz's claim that said even the girsa of the Yerushalmi is unreliable, not just the Halachot.
6. Given a Machaloket in the Bavli and a "Maaseh Rav" (anecdote about a Talmudic figure) in the Yerushalmi that takes a side, the Halacha follows the side expressed by the Maaseh Rav in the Yerushalmi.
7. The Poskim often try to harmonize the Bavli and Yerushalmi as much as possible.
8. Sometimes, when referring to topics in different locations, the Yerushalmi mixes up "here" and "there," because the topic appears more than once and the same text was copied/repeated completely from one location to the other without adjustment.

Differences Between Other Sefarim

1. When the Talmud and Zohar contradict, the Radbaz is well known for positing that one should follow the Talmud and Poskim.
2. When faced with a contradiction between the Yerushalmi and the Tosefta, the Rambam generally sides with the Yerushalmi. The Kessef Mishneh (Hilchot Maaser Sheni 1:10) explains that the authenticity of our set of Toseftas is questionable: they may not be the same Toseftas compiled by Rav Chiya and Rav Oshiya. The Peri Chadash (Orach Chaim Siman 450) adds that it's based on the Yerushalmi's later date of redaction. The Radbaz thinks the Rif takes the side of the Tosefta in such instances, while the Sdei Chemed thinks not so.
3. As we would follow the Yerushalmi against the silence of the Bavli, if there is a contradiction between a Midrash Rabbah and Yerushalmi, the Halacha follows the Yerushalmi over the Midrash.

Sefarim HaChitzonim (Masechet Semachot, Sofrim, and others)

1. Tosafot in a number of places writes how with respect to some Halachot, they follow Sefarim Chitzonim, such as Masechet Semachot and Masechet Sofrim, which were compiled later on, against the Talmud. They're called Chitzonim, according to the Bach because they are external to the Gemara, or, according to the Chidah, because they're even further removed from the Baraitot, which are already "outside," as their name suggests. Some say the Girsaot are also enigmatic.

Geonim

1. The term "Geonim" generally refers to those who lived between the Savoraim and the Rif, though the institution of Geonim did extend beyond then. Some say that the term Gaon is short for "Rosh Yeshivat Gaon Yaakov," while others claim it was reserved for those who were experts in all sixty Masechtot of Shas, corresponding to the Gematria of גאון.
2. The monograph on Hilchot Tefillin from the times of the Geonim is claimed by some to be super authoritative, as "the words of the Geonim are tradition" (דבריהם דברי קבלה) in that they had access to the first edition of Talmud Bavli, which was clearer than ours. At the same time, a number of Rishonim poke holes in the work and argue it shouldn't be followed when it contradicts Talmud Bavli.

Bahag (Ba'al Halachot Gedolot)

1. Often times, the Rishonim will disagree with the Bahag but conclude in favor of his ruling anyway, even if it's illogical, because "Devarav Divrei Kabbalah Hem." Because of the tradition stemming from the Amoraim, through the Savoraim, to him, the Bahag is granted special authority when the Gemara does not explicitly say otherwise; however, if the Rishonim feel the Gemara contradicts his words, then they freely disagree in practice, as well.
2. The Rishonim are uncertain if the Halachot Gedolot was authored by Rav Yehudai Gaon, who was blind, or by Rav Shimon Kayyara. Illogical rulings could be pinned on the former's students misinterpretation of their rebbe's words when writing his sefer. Some say Rav Shimon Kayyara wrote Halachot Gedolot, and Rav Yehudai Gaon wrote a different sefer known as Halachot Pesukot, while others claim they each wrote a sefer called Halachot Gedolot.

Rif

Practical Focus

The Rif generally quotes only relevant passages of the Gemara and leaves out points that aren't accepted at the end of the sugya. That said, there are some exceptions to be aware of.

1. Even though the Rif generally only records Halachot that are relevant nowadays, for example, to the exclusion of Kodashim, if a Halacha that is generally relevant has a detail that is not, he will write the entire Halacha including the detail. Moreover, if there is some relevant Halacha or Chiddush to derive from the irrelevant Halacha, then that Halacha will be included, as well.
2. If a din that does not appear to be subject of debate in the Gemara is only recorded partially in the Rif, it's an indication that the Rif holds the omitted segments are not accepted in practice.
3. Periodically, the Rif will quote a Tosefta by opening with Tanu Rabbanan, because the end of that Tosefta is quoted in the Gemara.
4. When the Gemara presents two Baraitot that each derive the same Halacha but from different sources (Tanya and Tanya Idach), the Rif will quote both.
5. However, some say he will not quote a Baraita that is not in line with the accepted Halacha.
6. If the Gemara presents an answer that unanimously resolves a difficulty in the Mishna but then continues to present additional resolutions from other Amoraim, which we would assume like in practice, the Rif will still quote the unanimously agreeable upon answer, even if it's not LeHalacha.
7. The Be'er Sheva advises one to not be surprised if the Rif omits the okimta of the Gemara in favor of his own original understanding, as he rathers to minimize Machaloket than quote the Gemara. The Yad Malachi argues lengthily against this approach and posits that the Rif merely omits Gemaras he feels to not be Aliba deHilcheta. The Rif and Rambam aren't Amoraim who have the ability to decide unresolved issues in the Gemara!
8. Similar to the rule of Stam vaYesh in reading Shulchan Aruch, when the Rif states that the Halacha follows a certain ruling but there are those who disagree, he intends to rule like the former and is only sharing the latter to transmit the rulings of earlier generations.
9. Unless explicitly stated by the Rif that one should be stringent, the assumption is that a lenient approach is taken with unresolved inquiries of the Gemara (Tiku)
10. Similar to Rashi, the Rif will only explain a Halacha with the words כלומר or פירוש to offer specifically this interpreation over a possible alternative one that would be subject to some question.

Rav Hai Gaon

1. "The Gaon" in the Rif's jargon most probably refers to Rav Hai Gaon.
2. When the Rif cites a ruling of Rav Hai Gaon without explicitly agreeing with it, the Raavad and Rosh believe that he is disagreeing, while the Rashba argues he is agreeing since he didn't state otherwise. The Yad Malachi finds that the Rashba is more logical, a great number of Rishonim side with him on this matter, and the former opinion isn't so clear in the first place.
3. After presenting a Machaloket, if the Rif concludes with citing Rav Hai Gaon as taking a certain side, that would indicates he agrees with that side, as well.

Misc.

1. There is controversy regarding the reliability and authorship of the Rif's responsa.
2. Rabbeinu Yitzchak ben Yaakov Alfasi, the Rif, had a grandson, Rav Yitzchak ben Reuven, who is known as the Baal HaShe'arim. Some Poskim weren't aware of this and mistakenly posed contradictions between the writings of the two.

Rambam

General

1. The Maharashdam believes that since the Rambam saw the other opinions on each issue and still decided the way we did, we should follow his rulings (analogous to the Radbaz and the Rif). On the other hand, a number of Ashkenazi authorities feel that the Rambam is a minority in the face of the Baalei HaTosafot.
2. One cannot pose questions from Tosafot's logic against the Rambam. Gavra aGavra KaRamit?!
3. The Rivash and Rosh warn that one who attempts to rule on practical matters solely from Mishneh Torah without understanding its Talmudic context will likely mistake Assur for Muttar and Muttar for Assur, thinking he understands the material. At the same time, the Rambam's explicit intention was to write the Halacha so clearly that one need not be bogged down by the confusing Sugya and need only Mishneh Torah to know how to act, so some Acharonim, such as the Ohr HaChaim and Baal HaTanya are less concerned. While that is true, the Rambam himself explains in a letter that he did so for people for whom understanding the Gemara was beyond their reach.
4. Seldom does the Rambam disagree with the Rif, so one should not assume so unless there are already a great number of Rishonim for him to side with.

Mishneh Torah

General Approach

1. In Mishneh Torah, the Rambam focuses on relaying rulings explicated in the Gemara in a lucid way, while leaving out rulings that can only be inferred but aren't stated explicitly.
2. The Rambam's style is to write only what it says in the Gemara and not the interpretation, but his intention is to for the interpretation of the Gemara to be applied to his words, as well, though some disagree.
3. It's abnormal for the Rambam to omit a din dealt with explicitly in the Talmud and instead write a different idea not mentioned in the Talmud that implies the one mentioned explicitly.
4. Counts of the number of Perakim, Halachot, Mitzvot, etc are provided in Mishneh Torah to facilitate memorization, not to imply additional ideas.
5. The Rambam will rule like a Halacha found in the Sifrei if it's not contradicted by the Talmud.
6. Every word of the Rambam is written with tremendous precision and exactness, enough for one to infer from his words as one would from the Gemara itself. Similarly, the Maharalbach warns that one shouldn't rush to reject the Rambam for coming off as against the Gemara, but should rather pin the in-congruence on our own lack of understanding.
7. One cannot infer from the presentation of a ruling in one section of Mishneh Torah and its absence in another seemingly appropriate section that it only applies in one and not the other, as the Rambam's goal is to present the Talmud's rulings in their wording in their appropriate place. For example, a Halacha in Terumot that might also fit in Maachalot Assurot cannot be assumed to only apply in Terumot and not Maachalot Assurot given its presence in the former and absence in the latter. This is, however, a valid tool in reading other Poskim, such as the Tur.

Writing Style

1. The word Assur is used even when referring to Dinim MiDeoraita that would warrant Malkot.
2. "MiPi HaShmua" refers to a Halacha whose source is not explicit in the Torah, and "MiPi HaKabbalah" refers to Halachot learned from Pesukim in Neviim.
3. The term "MiDivrei Sofrim" can refer to Dinim MiDeRabbanan, as well as any Din MiDeoraita not stated explicitly in the Torah, such as one derived via the thirteen Middot, because without the Chachamim it would not be understood.
4. Consistently marking each Din as a Gezeirah or Halacha LeMoshe MiSinai is not a priority for the Rambam: sometime he mentions the Din's classification, while other times he does not.
5. The Rivash argues that the Rambam will refer to a Takkanat Chachamim as "Torah," such as in "Lo Hikpida Torah" in reference to the Ne'emanut of an Ed Echad, while others disagree.
6. When the Gemara presents more specific arguments predicated on accepting one of two possible assumptions - "Im Timtzi Lomar" - the Geonim and Rambam understand that the Halacha assumes like that assumption. Some say this is only true if the Gemara did not leave the very same uncertainty pending with a "Tiku" elsewhere, while others argue the opposite. The two levels of the Im Timtzi Lomar cannot be interchangeable, meaning if assuming A over B and then asking C over D is equivalent to assuming C over D and then asking A over B, this rule does not apply for the Rambam. The words must also be explicit in the text of the Gemara, so two subsequent questions, one building on the previous, would not be subject to this rule. The Poskim dispute if this is only true when the Amora in the Gemara himself uses these words to navigate the situation or if it's even true when the omniscient narrator of the Sugya does so externally of the Amora's words.
7. If the Gemara presents two opposite understandings and then rejects one, the Rambam will formulate it in a way that accepts the accepted one and implies the rejection of the rejected one.
8. Often times, answers presented in the Gemara in rejection of a difficulty are omitted by the Rambam in favor of the simple meaning of the Mishnah, Baraita, or Amoraic statement.
9. It is not uncommon for the Rambam to pin a ruling on a Pasuk not mentioned in or even rejected by the Gemara, because he felt it to be simpler or more acceptable, especially if there's no practical difference.
10. In a few places, the Rambam employs a Talmudic phrase to mean something different from what it does in the Talmud.

Connections to Other Works

1. Though the Rambam never relies in Mishneh Torah on what he already wrote in Peirush HaMishnayot, he does rely on what he wrote in earlier sections of Mishneh Torah, and perhaps even later ones, or, at least, in that chapter.
2. When a contradiction is found between the Perush HaMishnayot and the Mishneh Torah, the Halacha follows Mishneh Torah, which was written later and as a set of rulings, not a set of elucidations of the Mishnah.

Sefer HaMitzvot

1. The focus of Sefer HaMitzvot is not to determine which Mitzvot are part of the 613, not to present a comprehensive of accurate representation of their Halachot and details. Therefore, when studying Sefer HaMitzvot, questioning the count of Mitzvot is wholly acceptable, but questioning the details of the Mitzvot is not. The Mishneh Torah was written to address those details, and, even if there are distinct differences, it's always possible that he changed his mind over time.
2. There's a debate regarding if specific Rishonim such as the Samag, Maggid Mishneh, and Migdal Oz saw the Sefer HaMitzvot, as it wasn't translated from Arabic to Hebrew for some time. Later Acharonim culled lists of instances in which each of them cites the Sefer HaMitzvot to dispel those claims.

Perush HaMishnah

1. In Perush HaMishnayot, wherever there is an opinion that misleadingly seems to be the minority one but is, in fact, the one the Halacha follows, the Rambam will buttress that opinion by writing of its truth or singularity or the like to indicate that the Halacha does indeed follow it.
2. Sometimes our translation of Perush HaMishnayot will refer to a din as being MiDeRabbanan, but it's probably just a mistaken translation of "MiDivrei Sofrim."
3. The Ramban did not have the Introduction to Perush HaMishnayot available to him, as Hebrew translations of the Arabic were not yet available in Spain, according to the Yad Malachi, who posits that had they been available, the Ramban would not have been as quick to argue.

Ra'avad

1. In a dispute between the Rambam and Ra'avad, some argue the Halacha should be treated as a Safek, while others favor the Ra'avad when he is more stringent than the Rambam, and still others are willing to be lenient like the Ra'avad against the Rambam.
2. When the Ra'avad presents a dissenting opinion with the opening of "Yesh Mi SheOmer," the Tur seems to think he actually paskens that way, but the Beit Yosef does not.
3. In his inimitable style, the Ra'avad's critiques of the Rambam should not be seen as personal attacks to belittle the Rambam but rather as means of raising the red flag to warn people not to follow the rulings he felt the Rambam was mistaken in presenting.
4. Neither the Rambam's Perush HaMishnayot nor Moreh Nevuchim were present before the Ra'avad, as they had not yet been translated from Arabic to Hebrew.
5. "Gedolei HaMefarshim" and "Gedolei HaMagihim" refer to the Ra'avad.

Sefer Mitzvot Gadol (Semag / Samag)

1. When quoting the Gemara, the Samag will often paraphrase to make the language flow more quickly.
2. The Samag draws heavily from the Rambam for the most part and entirely from his teacher, the Sefer HaTerumah, whose Maftechot he copied letter for letter. When in agreement with the Rambam, he writes so implicitly, and he only disagrees when out-rightly quoting the Rambam by name.
3. At the same time, most of his words are based on the Tosafot Shanz, and, for some reason, he does not seem to have seen the Tosafot Tuch.
4. The Bach says the Samag's way is to rule like the Ri Baal HaTosafot.
5. There's a debate if the Samag saw the Rambam's Sefer HaMitzvot or parts of it.

Rashi

Fundamentals

1. Rashi, colloquially known as "Kuntress," always takes the simplest Peshat of the Gemara, even if it's not in line with the accepted Halacha - even a Hava Amina rejected by the Gemara itself later on!
2. Along the same lines and by no means in disparagement of Rashi, the Radbaz alerts us that Rashi is primarily a Mefaresh, not a Posek, so much so that he doesn't even register as a Shitah when deciding a Machloket between Rishonim, such as the Rosh and Rambam., though some disagree.
3. In his inimitable and calculated pithiness, Rashi negates numerous difficulties with the understanding of the Gemara with just a few words. This is very much part of Rashi's claim to fame.
4. One cannot pose the tradition of the Geonim as a question on Rashi - "Gavra Agavra KaRamit?!"
5. Whenever Rashi uses the words כלומר he is offering that particular interpretation where one would have been able to offer an alternative one.
6. When Tosafot attacks Rashi with a series of difficulties from later Masechtot, one could argue Rashi assumes the Gemara at this point isn't working with them in mind.

Works Not by Rashi

1. The commentary on Divrei HaYamim is not by Rashi.
2. The commentaries on the side of the Gemara where Rashi should be on Masechtot Meilah, Nazir, and Nedarim, are not by Rashi.
3. There is a debate among Acharonim if the commentary of Rashi on Masechet Ta'anit is authentic or not; it seems that many Acharonim assume that it indeed is by Rashi.
4. The commentary Rashi on the Rif was compiled by a later student based heavily on Rashi.

Tosafot

1. When two Poskim each associate a different understanding with Tosafot, one could explain that they're referring to different Baalei HaTosafot.
2. Sometimes Tosafot will argue "Ein Lehakshot" - not to pose a question - but not provide the reasoning, thereby leaving it to the reader to derive the answer or they find it in a parallel Tosafot.
3. Even though Tosafot often poses a question with "Im Tomar" and answers it with "Yesh Lomar," there are instances where the question will be asked in the formal manner but left unanswered.

Further Reading

• Kenesset HaGedolah, Klalei HaPoskim
• Yad Malachi, especially the Machon Yerushalayim annotated edition
• Yair Ozen / Ein Zocher, by the Chida
• Shem HaGedolim, by the Chida
• Kol HaChaim, by Rav Chaim Palagi
• Sdei Chemed, Klalei HaPoskim
• Ein Yitzchak, by Rav Yitzchak Yosef