Most of us live upon a pedestal, and it's the legs that keep us propped up there. This is the sense in which the legs are used to support the ego: constantly straightening to push us onto the platform (soap box) our conditioned mind has created for us. So, that first instruction of taiji – sink & relax – let the legs give and bend, coupled with the humility of single-weightedness, is a radical combination – the beginning of the battle with our intransigent self. We must become so accustomed to slipping from our pedestal that no part of us wants to regain the arrogance that comes with perching upon it. Then the pedestal erodes away – crumbles effectively – and it is safe to venture into that middle ground between the legs without falling into the trap of double-weightedness.