Introduction -- Variable, identical, differential. Architecture and the identical copy : timelines -- Allography and notations -- Authorship -- The early modern pursuit of identical reproduction -- Geometry, algorism, and the notational bottleneck -- The fall of the identicals -- The reversal of the Albertian paradigm -- The rise. Alberti and identical copies -- Going digital -- Windows -- ID pictures and the power of facsimiles -- Alberti's imitation game and its technological failure -- The invention of the Albertian paradigm -- The fall. Form -- Standard -- Agency -- Epilogue. Split agency.