  The concept of resilience embodies the quest towards the ability to sustain
shocks, to suffer from these shocks as little as possible, for the shortest
time possible, and to recover with the full functionalities that existed before
the perturbation. We propose an operation definition of resilience, seeing it
as a measure of stress that is complementary to the risk measures. Emphasis is
put on the distinction between stressors (the forces acting on the system) and
stress (the internal reaction of the system to the stressors). This allows us
to elaborate a classification of stress measures and of the possible responses
to stressors. We emphasize the need for characterizing the goals of a given
system, from which the process of resilience build-up can be defined.
Distinguishing between exogenous versus endogenous sources of stress allows one
to define the corresponding appropriate responses. The main ingredients towards
resilience include (1) the need for continuous multi-variable measurement and
diagnosis of endogenous instabilities, (2) diversification and heterogeneity,
(3) decoupling, (4) incentives and motivations, and (5) last but not least the
(obvious) role of individual strengths. Propositions for individual training
towards resilience are articulated. The concept of "crisis flight simulators"
is introduced to address the intrinsic human cognitive biases underlying the
logic of failures and the illusion of control. We also introduce the
"time-at-risk" framework, whose goal is to provide continuous predictive
updates on possible scenarios and their probabilistic weights, so that a
culture of preparedness and adaptation be promoted. These concepts are
presented towards building up personal resilience, resilient societies and
resilient financial systems.
