On the relationship between “things” and “ideas” — with a special emphasis on medical practice. Dualism has a long track in philosophy. Although often overlooked, it supports much of our worldview, and lies at the center of many frontline scientific issues. This dialectic has specific phrasings in different scientific areas, but it is arguably the expression of the same conflict in diverse contexts: namely, the framework between Matter and Information, or, metaphorically, the frontier between the Territory and the Map. This book attempts to analyse this Map/Territory frontier in several quite different settings, including its relevance in the present trans-humanist projects. It tries to draw parallelisms and similarities between diverse territories (e.g. the idea of Entropy as the distance between the Map and the Territory, the dependence on deep 'hyperpriors' such as Space, Time or the 'Me/Not-Me' duality, etc). It also points at certain resonances between a number of very actual scientific problems and certain trends in oriental philosophy. This Map/Territory polarity is especially present in Medicine, and a significant part of the book addresses this polarity as it is perceived in clinical practice.The gap between the Map (disease as an entity) and the Territory (the patient’s ailment) is at the heart of most theoretical (and practical!) medical problems, and is the cause of many patient-physician misunderstandings. We cannot conceive a clinical practice without the concept of disease. But at the same time, we are all painfully aware of the inconsistencies and contradictions brought by this paradigm. The impending crisis derived from this approach, as well as some other alternative medical narratives are discussed.