The essay deals with the mind-body problem. The first part describes the different views held by philosophers from Plato up to modern times, stressing the standpoint of René Descartes for medical philosophy and dualism. The author outlines the new research field of psychoneuroimmunology, and asks whether this could be one of the keys to the mind-body problem. The concept of anomaly is discussed, taking placebo and nocebo as prominent examples. Finally the author outlines modern holistic thinking based on a general systems theory, with biology as a dynamic interplay of culture, ecology, mind, and body in an open non-lineary system.