 According to the massive modularity hypothesis, the mind is modular through and through, including the parts responsible for high-level cognition functions like belief fixation, problem-solving, planning, and the like. Originally articulated and advocated by proponents of evolutionary psychology (Sperber, 1994, 2002; Cosmides &amp; Tooby, 1992; Pinker, 1997; Barrett, 2005; Barrett &amp; Kurzban, 2006), the hypothesis has received its most comprehensive and sophisticated defense at the hands of Carruthers (2006). Before proceeding to the details of that defense, however, we need to consider briefly what concept of modularity is in play. 