How does a doctor or therapist bridge the gap between particulars and generalizations regarding patients and various phenomena or diseases? The authors of this volume illustrate the multiple ways practitioners in the fields of clinical psychology and medicine address the tension between the universal nature of scientific knowledge and its particular applications. They discuss the fact that some decisions, if made erroneously, have impacts that cannot be reversed. An error in the realms of medicine, ecology, peace, and war brings with it psychological strategies that differ from those a practitioner faces where errors are correctable.