In this first section of the book, the authors examine a selection of epistemological approaches provided by a complexity framework. They touch on the notions of boundaries between systems and ways in which systems interact, on the implications of different scales of analysis, and on the limits of the descriptions and models used in order to study phenomena. The authors argue for a plurality of approaches, in particular those that allow for integrating across theories and across methods within a transdisciplinary context or those that accept coexistence with knowledge other than the formal, with dimensions of history, and with subjectivity.