Standing up means voluntarily accepting the burden of Being. Your nervous system responds in an entirely different manner when you face the demands of life voluntarily. You respond to a challenge, instead of bracing for a catastrophe. You see the gold the dragon hoards, instead of shrinking in terror from the all-too-real fact of the dragon. You step forward to take your place in the dominance hierarchy, and occupy your territory, manifesting your willingness to defend, expand and transform it. That can all occur practically or symbolically, as a physical or as a conceptual restructuring.
