Natural philosophy once spanned the fields of philosophy, science, and medicine. Scientific disciplines and medical specialties have rapidly achieved independence, and the availability of the internet and open-access publishing promises a further expansion of knowledge. Nevertheless, a consideration of the grounding concepts and ethical principles that underlie health care remains paramount. It is timely, therefore, to contribute to the global conversation on health care with an open-access journal that focuses on addressing the conceptual basis of medicine and related disciplines, considering the ethical aspects of clinical practice, and exploring its intersection with the humanities (including history of medicine). © 2006 Stein et al; licensee BioMed Central Ltd.