There is a free lunch after all

The title of William Dembski’s book No Free Lunch (Dembski 2002a) indicates that he perceives the no free lunch (NFL) theorems (Wolpert and Macready 1997) as pivotal to his thesis asserting that “specified complexity cannot be purchased without intelligence.” Indeed, many statements in Dembski’s book emphasize the crucial role of the NFL theorems. However, in his response (2002b) to a review rebutting his use of the NFL theorems Dembski claims that the NFL theorems are secondary for his thesis, while his principal argument is related to a “displacement problem.” I will show in this chapter that neither the NFL theorems nor the notions related to the displacement problem support Dembski’s thesis. Critiques of of Dembski’s work can be found in a number of publications (Wein 2002a,b; Shallit 2002; Rosenhouse 2002; Perakh 2001a, 2002a, 2002b, 2003; Young 2002; Orr 2002; Van Till 2002). Here I will discuss only chapter 4 (Evolutionary Algorithms) of Dembski’s book, concentrating on his use of the NFL theorems and on his “displacement problem.”