You realize that the tail of a conventional airplane like the picture of the V tailed Doctor Killer actually "lifts" in the downward direction, to point the nose up and balance the airplane about the center of lift, which is somewhere in the main wing. It is actually acting against total uplift. It is exactly like our rudders on cats, you push on the tiller, make the stern of the boat go down (or away from the direction you want to go), so the bow will go up, like a teeter-totter, it pivots about the daggerboards (wings).
That is why Rutan designed canard type airplanes, (they tried this on an earlier America's Cup boat back in the 80's too, putting the rudder in the front to increase lift when turning) where the canard is in the front of the main wing, and does help to lift the total weight of the airframe along with the main wing. And he designed it so the canard would stall before the main wing stalled, so it was much safer. I don't know why Boeing never built one too.
Here's some light reading on the subject of Burt Rutan's designs. Now, if we could just get him to design catamarans... <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
