The return of the abortion debate -- and its pious rhetoric I see we're debating abortion again. This is where I came in 30-some years ago. Out come old arguments from the mothballs, along with old proponents and opponents. Only this Monday I read somebody saying that, well, you can outlaw abortion, but women will just keep doing it in back alleys. Arguing without a shared premise is like playing tennis without a net. We've reached an impasse 30-some years ago, but pro-lifers are getting restless, and one judicial appointment could change things. This impelled my old pal and debating partner, the civil libertarian Alan Borovoy, to ride again, presumably to stem the tide of fetal menace threatening to engulf us all (" Why personhood is beside the point ," Oct. 29). Indeed, Borovoy argues that "even if we assumed that personhood begins at conception, why should that 'person' have sanctuary in the body of someone who doesn't want it there?" Well, ahem, because she put it there in the first place, Alan, wouldn't you say? But Borovoy raises the point only to make clear he doesn't want to hear about it: "The abortion debate should focus less on the mysteries of embryonic life and more on the limits of governmental power." Well, yes, shifting gears is wise because embryonic life isn't all that mysterious. What comes out of the womb in nine months, sans interference, is a baby, not a tissue sample. One could respectably argue, though, as Borovoy