Not much and at the same time everything. The 'short' answer is there's a lot of things forbidden on the Sabbath/Shabbat under Judaism, those are all forbidden; making fire (interpreted now to include operating basically any electronic switch), cooking (heating water included so no hot water UNLESS it's water already heated in the tank [0]). You can however reheat food it seems [1] provided the oven/warming tray runs continuously so you're not creating new fire/increasing existing fire/god knows what else.
The accumulation of interpretation and rulings on various situations under the law means there's a thousand edge cases that have probably been brought up over the centuries and some ruling made. It all feels a bit like trying to rules lawyer god which is amusing to me as a TTRPG player but sounds exhausting if it were my real life.
[0] Though you also have to shut off the inlet water to the tank because the new water entering and being heated by the existing heated water (which you can use) counts as a violation. Source: https://www.star-k.org/articles/kashrus-kurrents/579/getting...
I would refer people to the dual definitions of the word "Talmudic"[1] for further proof of this:
1. of or relating to the Talmud (the collection of Jewish law and tradition)
2. characterized by or making extremely fine distinctions; overly detailed or subtle; hairsplitting.
It is extremely difficult to translate rules that were written thousands of years ago into guidance on modern life. Much of Jewish religious tradition has therefore embraced the debate, theorizing, and further definition of these rules into something that is more clear, logical, and can be practically applied by people who wish to follow them.
"Does electricity count as fire?" might seem like an arbitrary and non-sensical question to someone on the outside, but it is incredibly important to how a modern Orthodox Jewish person would practice their religion and they therefore need an answer to it. "Trying to rules lawyer god" through debate and writing on the subject seems like one of the better ways to reach a satisfying and conclusive answer to this style of question.
The parts where it goes from 'seriously trying to follow the precepts of my religion' to 'rules lawyering' to me is the stuff like the eruv that encircles most of Manhattan [0] extending the 'private' zone where jews are allowed to carry things on the Sabbath or the decision that you can keep food warm in an oven so long as you take it all out at once so the additional burning that takes place after you open the door (your actions changing the functioning of the machine) is wasted and therefor unintentional (similar to the Sabbath mode on elevators).
Both of the cases you mention are still 'seriously trying to follow the precepts' (for many Jews, at least). A lot of (Orthodox) Jews seem to have this idea that an Eruv is this big wink-wink-nod-nod loophole which blatantly circumvents a biblical prohibition through somewhat arbitrary (ie. Lacking in essential religious meaning) legal gymnastics.
This is not the case. An Eruv is actually a beautiful example of the halakhic (translate: "Jewish law") process working as it's supposed to. Its implementation combines sharp hermeneutics with a sensitivity to the needs of real communities and a strong understanding of the meta-halakhic principles which drive the entire process
I'm not really sure if a sub- comment on HN is the right place to expand on this, but I'm happy to discuss it via some other medium.
Oddly enough, Jews are encouraged to do this! We were given brains for a reason and we were also given the frameworks for making decisions about the law as technology and society changes.
Many of the decisions also require deep knowledge into the subject matter (not just the Jewish law) in order to make a ruling. To allow electric switches one would need to know all the intricacies of both Jewish law and electricity before a valid ruling could be made.
This is interesting. Although I'm an atheist and have been for pretty much my entire life, I find Judaism fascination from a cultural perspective, and I have immense respect for it as a belief system.
How exactly are Jews encouraged to "rules lawyer God?" Is it literally what you said: that God gave us brains, and he expects bus to use them? Where can I find out more about this? Is there some kind of "guide to Jewish law for goyim" I can check out?
I'm sorry I don't know of any particular singular resource you can check out (I know they exist, but I can't think of a good one off the top of my head), though feel free to email me and I will happily answer any question you might have.
Note that the mystical and the magical elements of the story are often seen as the rhetorical flourishes and metaphors of the Talmud's storytelling style. The fundamental point is that even if a voice rang down from heaven declaring the law to be a certain way, a majority opinion among sages would overrule said voice. The Torah (law and teachings) was given to Jewish people, and it's now our job to interpret and wrestle with the particulars.
(I mentioned this is as a partial answer to your question, because there is a lot of nuance and further thought based on the idea. It does not, for instance, suggest an each-person-for-themself personal reinterpretation of the body of laws. It is more supporting the idea that as a society it is up to us to collectively define, refine, debate, and expand on these teachings.)
There's a famous Jewish story about four Jewish sages disagreeing about something and one of them calling out to God to confirm he's right, and the voice of God actually booming from heaven and saying "yes, so and so is right!". The remaining sages retort "well, there's still three against two". The canonical meaning of this is that the sages in the majority actually were acting correctly. So the rule lawyering is not a bug, it's how it's meant to work :)
I have a horrible feeling I'm Jew-splaining here, but I absolutely love the story and want to give more context for people who don't know it.
Your anecdote is the last in a series, describing a debate between Rabbis Eliezer and Joshua about the kosher status of the Oven of Akhnai (a clay oven which had been ritually polluted through proximity with a corpse, but was then broken up and remade). The first anecdote has Eliezer saying, "If I'm right, let that carob tree get up and move over there!". The tree did indeed uproot itself and move a substantial distance. His interlocutor retorted "pah, what does a tree know?".
In the last anecdote as you describe, Eliezer calls out to God to back him up, and indeed God booms forth, but Joshua replies, "it [the Jewish law] is not in heaven". That is, human law is for humans to interpret, not God. It amounts to an effective way to protect the system from wholesale change by new prophets who claim to be conveying the word of God.
All cribbed from David Friedman's _Legal Systems Very Different From Ours_, an absolutely fascinating book which I strongly recommend.
As a non-Jew I sometimes find it interesting to read articles on chabad.org, which provides really detailed descriptions of all these rules on almost every topic. For example, here are the rules for reheating food on the Sabbath:
I find the Judaism stack exchange https://judaism.stackexchange.com/ one of the weirdest and most interesting of SE pages. I mean that in the most voyeuristic sense, as a complete atheist. Start clicking front page questions and you'll likely soon go "huh?"
As a Jew, I must admit that Christianity SE gives me much the same impression. (Indeed, any site with a lot of unfamiliar jargon ends up feeling a bit like that.)
That is interesting. Would you consider the teachings of Judaism to be more or less authoritative than the biblical/original scriptures? (Sorry I don't know the Jewish phrasing beyond maybe the "the books of Moses")
These things you describe seem like a lot of work with not much result. Do you find it onerous to observe the rules you described?
The Orthodox view is that primacy is given to the present Rabbinic interpretations (and extensions) of the law beyond the literal meaning of the Biblical canon (called "Tanakh", which includes the 5 books of Moses as well as the writings of some later sages and prophets).
It is considered heresy to view the Bible/Tanakh as the last word on a law. Instead, the Rabbinic derivations are seen as capturing the underlying intent of biblical law as it may actually manifest in real societal practice.
An example is the famous "take an eye for an eye" statement, which is interpreted Rabinically as referring to monetary compensation for damages. Actually seeking to physically harm someone in accordance to harm done to you is a gross violation of law.
The "eye for an eye" makes some sense in your description, as it seems to be against other biblical directives.
Where can I look into your statement "It is considered heresy to view the Bible/Tanakh as the last word on a law."?
This is is a new idea that I had not heard before, and it would explain a lot of discussions I have had over the years if I understood it's source. (I keep the sabbath, annual holy days, but not the Jewish laws, so I have had some interesting discussions over the years)
Orthodox (and broadly, "Rabbinic") Judaism place equal weight on the "Oral Torah" – a set of evolving traditions and insights which orbit the written books in vast and intricate constellations. To deny the validity of the Oral Torah is considered heretical. If you were to just follow the 5 books, and nothing else, most modern (Orthodox) Jews would say "that's not Judaism [as we understand/perceive it]".
For a bit more info I found this Quora question, which has some good answers: https://www.quora.com/Do-people-of-the-Jewish-faith-interpre... (Only the first 3-4 answers, after which the answers divert into jokes, and a very odd fire 'n brimstone answer.)
It’s only the cold water entering the hot water tank that provides pressure for the hot water to flow, so if you turn off the cold water inlet, you still can’t use the hot water already in the tank, by the laws of Newton and Bernoulli.
This is totally irrelevant to the discussion here - you're referring [in a rather toxic way] to ultra-Orthodoxy. My experience has been that ultra-Orthodox Jews are far less interested in and aware of the "thousand edge cases" since they prefer to stay far away from the proverbial 'edge'.
no it is not, it is called that only by those who does not follow (and which these same rules does not make a difference in their lives) and for some reason feel entitled to be offended for others
The accumulation of interpretation and rulings on various situations under the law means there's a thousand edge cases that have probably been brought up over the centuries and some ruling made. It all feels a bit like trying to rules lawyer god which is amusing to me as a TTRPG player but sounds exhausting if it were my real life.
[0] Though you also have to shut off the inlet water to the tank because the new water entering and being heated by the existing heated water (which you can use) counts as a violation. Source: https://www.star-k.org/articles/kashrus-kurrents/579/getting...
[1] https://www.star-k.org/articles/kashrus-kurrents/476/oven-ka...