i admit in advance that i haven't thought this through to the end, and shouldn't really ask you a question without first analyzing the situation properly, but you are so helpful that i cannot overcome my yetzer horoh to present my thoughts even at this stage.
the mishnah talks about when tumas hatehom cancels the nezirus (soser) and when it does not. it seems to me, however, that this only relates to the question of "soser" but not to the question of the tumah itself which is determined by the ordinary rules (tumas hatehom, safek tumah bireshus harabim, bireshus hayachid, etc.). thus, the nazir is tamei mes but not soser in certain situations (not only here but also with regard to reviis dam beohel etc.). indeed, the beginning of the mishnah uses the words soser and aino soser. however, when the mishna explains (i.e. "keitzad") the mishna uses the terms tamei and tahor and not soser or eino soser. now, i understand that the mishna can mean tamei for nazir purposes and tahor for nazir purposes (although the person is tamei for tumas mes purposes). however, then the mishna justifies its answer by relating to chezkas tamei and chezkas tahor, which are relevant concepts if we are talking about tumah and tahara, but not -it seems to me !!
- if we are talking about setirah. i know that at the end of the day the issue is halacha lemoshe misinai and that the rishonim try to explain the relationship between the logical analysis and the halacha lemoshe misinai. but my question is that i don't understand the relationship between the logical analysis (which relates to tumah and tahara) and the issue at hand (which relates to soser and eino soser). i think that my point applies whether we learn the sugya like tosafos or the rambam. i know the shev shematsa discusses this sugya but i haven't had a chance to look at it yet. actually the fact that the shev shematsa deals with this hints that he views this as a rule of chazaka etc (the subject of his sefer) which is my question -i.e. the jump between actual tumah and tahara to the subject of soser and not soser (even if the person is tamei in the rules of chazaka and tumah).
in any case, if my question makes no sense, i apologize in advance, since as i said i am giving in to my yetzer horoh by submitting this question at this stage of learning the sugya. if the question makes no sense, then please do not post the answer on the web.
have a nice day.
dmartin, raanana,eretz yisroel