In a lecture on Bauhaus delivered in Weimar in 1998, Daniel Libeskind compared the work of memory with "a light we forgot to turn off at night" which "reminds us the next day by its very own faintness of the forgotten events of the night" (SE 21). He also expressed his belief that "the ethic is indeed an optic since it makes visible our own relation to and responsibility for history" (SE 21; my italics). It is probably to Bauhaus that Libeskind owed his interest in optics, through which he connected visual perception to memory. Optics had become important for this movement since 1923, when László Moholy-Nagy joined Walter Gropius's School as professor and overseer of the metal shop. His famous kinetic sculpture, Light-Space Modulator (1922–30), was an abstract experiment in visual aesthetics and the law of optics.¹