To the Editor: There is a third world that Blackburn does not acknowledge in the binary system of thought that he uses to describe the problem of coronary heart disease (N Engl J Med 292:105–107, 1975). Those with what he calls the “academic view” comprise the lipoprotein-phenotyping contingent, who in effect say, “Give us more time and money and in the meantime phenotype everyone, even babies, and send off to Washington for the appropriate diet manual.” This looks to me like busy work — not problem solving. In the second world — where Blackburn lives in a large, circular, stone. . .