Bill Daniels wrote:
...
The counter argument that suggests that the horizontal tail is flying at a
positive angle of attack when the glider is flown near minimum airspeed must
assume that the pitching moment of the wing produces an nose-up pitching
moment that exceeds the nose-down moment of the CG acting ahead of the wings
center of lift - OR that the CG is placed aft of the center of lift. Both
of these conditions would produce serious static pitch instability which
would not pass JAR 22 certification standards.
...


Here is the point where I think there is a confusion. What do you call "center
of lift" ? The pitch stability needs only that the neutral point is behind the
CG, the neutral point is the location of the increment of lift provided by
all surfaces (wing and tail plane) when there is an increment in AOA. If you
call "center of lift" the point where you can reduce the lifting forces on the
wing only to a single vector (this is implied by what you say concerning
the pitching moment created by weight and lift) this is a different point which is
moving forward when the AOA increases and may be ahead of the CG at high
AOA, while the neutral point is always behind it. The confusion is both
betweeen an incremental force and its actual value and by the force provided
by the wing only and by wing + tail plane.