The Howell Theory of Blood Coagulation: A Record of the Pernicious Effects of a False Theory

Theories of blood coagulation originated with Hippocrates and Aristotle. There have been as many theories as investigators, and many have represented regression rather than advance of the subject. The accepted views in 1988 are based on the Morawitz-Fuld-Spiro formulation of 1905. However, this formulation was not accepted in North American medical teaching between 1911 and 1941. This was due to acceptance of the views of W. H. Howell. Howell proposed a hypothetical inhibitor, antiprothrombin, which he identified as a phospholipid and gave the name heparin. These views were identified as the Howell theory of blood coagulation and taught in all North American medical schools. The influence of this ubiquitous theory on editors and referees was so great that the new discoveries—measurement of prothrombin, preparation and nature of prothrombin, antihemophilic globulin, vitamin K, etc.—met great difficulties in publication and some were even blocked. The same influence caused equal and more prolonged difficulties for the development of heparin and in obtaining recognition of its unique chemical nature and biological actions.