Table 1. Comparison of assumptions about resilience and surprise. Communicative Planning Perspective Social–Ecological Resilience Perspective What is “resilience?” An ability to maintain equilibrium or “bounce back,” in the way that physicists and engineers refer to a material’s ability to absorb energy when it is deformed elastically and then to recover that energy upon unloading (Hollnagel et al. 2006). How far a particular relationship between social processes and ecological dynamics can be perturbed without dramatic loss of identity and structural and functional complexity (Holling 1973). What is “resilient?” A social condition, defined at the level of community, organization, city, region, or globe. Ecological and technological factors are monitored and managed to sustain social integrity, but are not part of what is resilient. A multi-scalar social and ecological condition, because a social system cannot be dissociated from the biosphere. What are “surprises?” A narrow range of unexpected destructive shocks, rapid and discrete events such as technological failure, hurricanes, and violent attack. Range from sudden, rapid, discrete, and irreversible disasters to more gradual and insidious events, such as climate change. Also encompass incremental, discontinuous, and spatially heterogeneous events like declining agricultural productivity, as well as events that escape notice because they are novel or occur imperceptibly over generations. Where do surprises come from? Originate outside of the community, as threats to the community’s security and durability. Can be both external to a community and endogenous to it, such as regime-change thresholds and other system dynamics. What is the relationship between surprises and resilience? Surprises are harmful and undesirable events that threaten resilience, and conversely systems that are vulnerable to surprises are always less resilient. Surprises are sometimes harmful and sometimes beneficial, because they can contribute to resilience or detract from it, endangering system continuity and integrity or marking thresholds for system transformation when existing conditions are untenable. Conversely, vulnerability to surprise could threaten or enhance resilience.