Last modified on September 26, 2018, at 20:07

Smoking gun (scientific discourse)

For the general usage of the metaphor of the "smoking gun", see Smoking gun.

In scientific discourse, the phrase Smoking gun is sometimes used to denote an evidentiary trace (or subcollection of traces) that unambiguously descriminates one hypothesis from among a set of currently available rival hypotheses as providing "the best explanation" of the traces thus far observed.[1] It is always possible that future observations or theoretical developments will depose a smoking gun and that another hypothesis (new or old) will attain status of the best explanation. Some of the factors that go into transforming a trace(s) into a smoking gun for a particular hypothesis may be sociological or psychological, especially in the field of historical science where direct observation of past events is not possible and testing of hypothesis producing supporting evidence might be obscure. A search for a smoking gun may also turn up evidence against a target hypothesis.

Some historical scientists use the term "smoking gun" very loosely and rampantly in their informal and popular works to degree that it became a subject of criticism by James Powell who refers to it as to the "tiresome metaphor of 'smoking gun'".[2]


  1. Cleland, C.E. (September 2002). "Methodological and Epistemic Differences between Historical Science and Experimental Science" (PDF). Philosophy of Science 69: 474–496. Retrieved 25.1.2012. 
  2. James Powell (1998). Night Comes to the Cretaceous. Harcourt Brace, 115. ISBN 978-01560-07030. “One could describe this result using the tiresome metaphor of "smoking gun"...” 

See also