While usually focused on designing buildings, designers might also design the medium in which those buildings are suspended. Beyond associations with communication technologies, medium, in this context, means middle or milieu. Considering ground instead of figure, or field instead of object, medium design inverts some dominant cultural logics and offers additional aesthetic and political capacities for addressing intractable problems. Medium is assessed for latent properties that unfold over time and territory, propensities within a context, potentials in relative position, or the agency in arrangement, and like an operating system or a growth medium, it decides what will live or die. In this matrix of activity where it is easier to detect discrepancy, latency, temperament, and indeterminacy, right answers are less important than unfolding or branching sequences of response. Benefiting from an artistic curiosity about reagents and spatial mixtures or spatial wiring, medium design suggests different organs of design or di≠erent ways to register the design imagination. Beyond buildings, master plans, declarations, laws, or standards, it deploys multipliers, switches, or time-released organs of interplay like bargains and chain reactions. While not dominant, this habit of mind is ever-present in many disciplines and leads to readings that include Michel Foucault, Giorgio Agamben, Gilbert Ryle, Gilles Deleuze, Bruno Latour, J.J. Gibson, Marshall McLuhan, Harold Innis, Jacques Rancière, Walter Benjamin, Gregory Bateson, Vilem Flusser, Dunne and Raby, and John Durham Peters. An in-class presentation and final paper complete the requirements of the course. Limited enrollment.