["Health is a Crossroad"--Nature and society, individual and community, in safeguarding public health].

Any person actively engaged in the sphere of Public Health who refers to "molecular medicine" is bound to arouse suspicion. Nevertheless, neither Public Health nor public health protection or the health sciences in general can afford to ignore medicine and biology. This fundamental fact is explored in a historical and subsequently in an anthropological context. The connections between molecular medicine and public health are discussed at length. Accordingly, health on an individual as well as on a social level is essentially bound to the knowledge of genetically determined dispositions. We may expect that this molecular-genetic reality will become as "true" in future as the hygienic-bacteriological reality has become "true" today. The medicalisation of all human realities will be continued by their "molecularisation". It is important to fundamentally understand the actual effects of this transformation, which is the subject of a wider public discussion. This is the only way to rationally estimate both the opportunities offered by molecular medicine and the involved risks. It is essential for a debate of this kind within public health care institutions that the public health movement addresses the current developments of molecular medicine in a critical but constructive manner. "Nature", and with it the medicine and biology of public health, is an essential aspect of protecting public health. This is the only way to clarify the sphere of activity of public health protection in general, to appreciate its dynamics and to develop adequate measures: "Health is a crossroad" according to Julio Frenk: "It is where biological and social factors, the individual and the community, and social economic policy all converge".