On Types of Scientific Enquiry: the Role of Qualitative Reasoning

David A. Freedman

in The Oxford Handbook of Political Methodology

Published in print August 2008 | ISBN: 9780199286546
Published online September 2009 | | DOI:

Series: Oxford Handbooks of Political Science

On Types of Scientific Enquiry: the Role of Qualitative Reasoning

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  • Political Methodology
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This article argues that ‘substantial progress derives from informal reasoning and qualitative insights’. It shows the role played by causal process observations (CPOs), and qualitative reasoning more generally, in a series of well-known episodes drawn from the history of medicine. Edward Jenner published twenty-three case studies to demonstrate the safety and efficacy of ‘vaccination’. Ignac Semmelweis discovered the cause of puerperal fever. John Snow revealed that cholera was a water-borne infectious disease, which could be prevented by cleaning up the water supply. Christiaan Eijkman's research plan was to use Koch's methods, and show that beriberi was an infectious disease. Joseph Goldberger believed that pellagra was a deficiency disease. Frederick McKay and his connection with fluoridation, and the discovery of Alexander Fleming to penicillin, are discussed. In addition, the breakthrough of German measles by Norman Gregg is reported. Finally, Arthur Herbst offers the association between diethylstibestrol and adenocarcinoma of the vagina.

Keywords: qualitative reasoning; causal process observations; Edward Jenner; vaccination; Ignac Semmelweis; puerperal fever; John Snow; cholera; Christiaan Eijkman; beriberi

Article.  8385 words. 

Subjects: Politics ; Political Methodology ; Comparative Politics

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