The incline plane is three dimensional- Down- Out and Through. To stay On Plane all three will feel like One.
If you break them into stations- Down goes the right shoulder and arms, Out goes the clubhead with the turning body and clubhead travels Through the ball On Plane. Of the three- DOWN will always be felt. You can't cheat Down.
I quoted from text that Lynn posted, not sure if its from the book. I understand the inclined plane and all that but in the passage there is a distinction made between "down" and "toward".
I took it to mean 'driving toward the plane line' but not 'down the plane line' hence I can't discern the difference.