Behaviorism and mentalism are commonly considered to be mutually exclu
sive and conjunctively exhaustive options for the psychological explan
ation of behavior. Behaviorism and mentalism do differ in their charac
terization of inner causes of behavior. However, I argue that they are
not mutually exclusive on the grounds that they share important found
ational assumptions, two of which are the notion of an inner-outer spl
it and the notion of control. I go on to argue that mentalism and beha
viorism are not conjunctively exhaustive either, on the grounds that d
ropping these common foundational assumptions results in a distinctive
ly different framework for the explanation of behavior. This third alt
ernative, which is briefly described, is a version of non-individualis
m.