Building resilient systems is a promising way to prepare for the unexpected. It goes far beyond the ‘what-if?’ approach, far beyond learning from bad experience (a posteriori). The ‘whatever-may come!’ approach has to find another a priori source of information. This can be found in nature and evolution. The creativity of evolution is not based on experience; it is totally random mutagenesis. Experience comes with the following step of selection, so ‘learning from nature’ is a possible way to tap a priori knowledge about design principles for ‘resilient systems’. In this way we tie in with the original ecosystem and evolutionary approach of Holling (1973). But this is only the beginning. The next step is the quite complex ‘biomimetic process of abstraction’ in which the identified architecture and parameters of natural systems are transferred into design principles and capabilities. Finally, the contributions from the approach of ‘learning from experience’ in socio-technical systems (risk management) and of ‘learning from nature’ (biomimetics) are assessed in order to formulate the demands of a guiding concept of ‘resilient socio-technical systems’.