It seems that, at this point, the argument that DovBear is putting forth is that the entire concept of the World to Come (and the Resurrection) stems not from Sinai, nor from the Torah itself, but rather is purely aggadic in nature, and thus, can, in theory at least, be disregarded as non-literal or even rejected outright. This is my understanding of his argument; correct me if I am wrong.
But, as it stands, it is here that I seriously part ways with Mr. DovBear. I completely fail to understand how this argument can be made with any level of seriousness. The Mishnah and Gemara itself writes that if someone does not believe in these things they are an apikores (11th perek in Sanhedrin)! This is a halachic decision. The Mishnah takes the World to Come for granted, and then proceeds to list those that forfeit it, such as those that deny the Resurrection. Are we to say that the Mishnah is aggadic? Are we to say that this Mishnah is not binding? It’s a Mishnah for goodness sake.
So what are we going to do? The Mishnah is lav davka? We’re making things up now?
The Mishnah sees this as binding. Thus, the Mishnah sees this as part of the tradition from Sinai, and the various drashos are nothing more than seeing where it is in the Chumash. Indeed, by the fact that the drashos that are there are not exactly ironclad, more like asmachtos, it might well be a halacha Moshe MiSinai with no real source in the Torah — but the Gemara there certainly implies that it is a drasha gemurah in the Torah! Anything that the Gemara sees as a drasha gemurah is perceived as a peirush Torah Sh’ba’al Peh. So you’re running either into regular Torah Sh’ba’al Peh, or halacha Moshe MiSinai. I’m no expert on drashos, but either way, I fail to comprehend DovBear’s position on this matter.
Or, at the very least, the Mishnah sure doesn’t.