[Avodah] Halacha as a System and Deriving halachah for new situations (two subjects for the price of one!)

[David Riceman via Avodah]

RMB:

<<Doesn't it have to be because HQBH gave us the system?
Othewise, why does the Tanur shel Akhnai story end with Him laughing 
"nitzchuni banai"?>>

Look at the Sidrei Tohoros ad. loc. (Keilim 5:10):

http://www.hebrewbooks.org/pdfpager.aspx?req=20463&st=&pgnum=191

He posits a mahlokes rishonim about whether this is a mahlokes about (1) 
whether hakol holech ahar hama'amid is a din d'orayysa which applies 
l'kula and l'humra, or a din d'rabbanan which applies only l'kula, or 
(2) whether the oven still has the status of a broken kli, i.e., what is 
customary usage of ovens.

The ST prefers reading (2).  According to reading (1) God thinks that 
this is a din d'rabbanan, but he acknowledges that the Rabbis have the 
authority to construe it to be a din d'oraysa.  I think the gemara in BM 
needs more elaboration according to this.  It stretches the concept of 
d'oraysa very far.  Perhaps RMB can elaborate.

According to reading (2) whether something is an oven is determined, not 
by Platonic ideals of an oven, but by prevalent human behavior. The 
Rambam in several places in H. Mamrim perek 2 (see especially 2:7) talks 
about BD observing what people do, but I'm not aware of anyone who 
suggests a methodology for this.  Could it be that R. Eliezer's opinion 
reflected local practice in his home town and Hachamim were trying to 
normalize practice everywhere? In that case "nitzhuni banai" could mean 
that their methodology gave them the wrong answer about how many people 
connected oven pieces with sand, but they nonetheless had the authority 
to enforce their mistaken result.

RMB:

<<And why would decisions about what would work override actual 
miraculous evidence? I am developing the theory that the reason for "lo 
bashamayim hi" is because "befikha uvilvakha la'asoso". That just as all 
of Torah is an elaboration of "mah desani lakh, lekhaverkha lo sa'avod" 
to an extent beyond a human's ability to work out, the same is true in 
the converse. Halakhah cannot be decided in shamayim, detached from a 
heart that has a natural moral calling.>>

To some extent this is what the Ran argues in the passage I cited in a 
previous email.  But "natural moral calling" is too constraining. One 
can make a plausible argument that dinei tumah and taharah have a moral 
dimension, but can one make such an argument about the construction of 
break-down ovens?

I'm hoping to write one more email about my own opinion on this topic.

David Riceman