Few figures of classical rhetoric can claim more spatial relevance than "chiasmus," the figure of symmetrical convergence used by poets, novelists, rhetoricians, mnemonicists and others. Is chiasmus a tool of literati who appropriate spatial forms to pull their plots to closure, or is there an independent architectural tradition of chiasmus? If one pulls together the clues about metonymy, the logic of arrangement, one can discover an intriguing link to Jacques Lacan's similar design of the human psyche and his topological investigations. The Vitruvian sequence of venustas, utilitas and firmatas may suggest to some nothing more than an arbitrary division of architectural interests. Ritually, however, the relation of firmitas not just to material stability but to the traditional rituals required to secure buildings from both collapse and curse, even if figurative, offers connections to the chiastic design of foundation rites, where sacrifice secures the life and security of structure.