Pettigrew Petrified 2

Digital photograph of polished petrified wood used in the construction of the historic Pettigrew Home and Museum in Sioux Falls, SD

The method of Abduction, as described by C.S. Peirce and expanded by Gregory Bateson:

"A surprising fact, C, is observed. But if a proposition, A, were true, C would be a matter of course. Hence, there is a reason to suspect that A is true."