[Avodah] Tayshvu K'ein Taduru

[David Riceman]

kennethgmiller at juno.com wrote:
> As I understand it, the mitzvah of sukkah exists on three levels, and all of them are d'Oraisa:
>
> 1) There is a Chiyuv D'Oraisa to eat bread in the Sukkah on the first night, whether he wants to or not.
>
> 2) After the first night, if he chooses to eat a Seudas Keva, he has a Mitzvah Chiyuvis, on a d'Oraisa level, to eat it in the Sukkah.
>
> 3) If he chooses to eat a Seudas Arai, he has a Mitzvah Kiyumis, on a d'Oraisa level, to eat it in the Sukkah.
>
> <snip>
>   
> The smallest of my questions is that if Tayshvu K'ein Taduru teaches that eating a Seudas Arai in the Sukkah is optional, then from where do we know that we get s'char if we choose to do so? In other words, if Tayshvu K'ein Taduru teaches that the Mitzvah Chiyuvis doesn't exist for a Seudas Arai, then from where do we learn that the Mitzvah Kiyumis *does* exist? Maybe there's no Mitzvah Kiyumis at all, and it is merely a Hanhaga Tova?
>   
I like my house.  I do many things (such as work) in my house which many 
people do in places other than their houses.  I could, for example, walk 
a block to the library to read email (the library has wifi).  But I 
don't, because I like hanging out at home.  I think the idea of a kiyum 
comes from this simple observation.  Most people use their houses for 
more than the minimum of what people use their houses for.  So those 
other usages are also k'ein taduru.
> It makes me wonder if Levels 2 and 3 are d'Oraisa at all. Is it possible that there really is no pasuk anywhere that requires a Seudas Keva (after the first night) to be eaten in the Sukkah? Is it possible that this chiyuv is actually a d'Rabanan?
>   
The d'orayysa and d'rabbanan distinction is a red herring.  The 
determination of what actions require a sukkah is sociological.
> But is that really so? Let's think back to the recent discussions about Shmini Atzeres in chu"l. There are a variety of conclusions on what the Halacha L'Maaseh is, but I'd like to cite one of the arguments which was used in those discussions. Consider this statement: "Presuming the weather is good enough, it is not out of the ordinary to eat a seudas keva in the backyard instead of in the house." It seems to me that no Rishonim or Acharonim disagreed with that statement. (They might disagree with the halacha, but they don't seem to disagree with this statement of common eating practices.)
>   
I recall recent aharonim arguing like this, to avoid the problem of bal 
tosif.  Does this argument appear anywhere in Hazal or rishonim? I 
suspect that halacha gelled in an era when people didn't eat full meals 
outside except in extremis, and the basic sifrei psak reflect that 
archaic reality.

David Riceman