The public health service likes to describe itself as a kind of "third pillar", which together with the two other "pillars"--out-patient and in-patient care--supports the system of health service of the FRG. In fact, in the years since 1945 no health or sociopolitical programme of an extensive health care system could be developed which would have linked these three "pillars" in a sensible division of labour. On the one hand, original tasks of the public health system have been transferred to the private system of health care stressing the subsidiary of governmental action. On the other hand the public health service did not succeed in transforming the classical health care into a convincing system of local health service, which could fill the obvious gaps in the other parts of the health system. At present it is again under discussion whether public health service will play an original part in the system of health care, whether, following the principle of subsidiary it will only be assigned those tasks which nobody else will or can tackle or whether these will be complementary to those of the other sectors.(ABSTRACT TRUNCATED AT 250 WORDS)