This paper is a discussion of the tenability of methodological solipsism, which typically relies on the so-called Explanatory Thesis. The main arguments in the paper are directed against the latter thesis, according to which internal (or autonomous or narrow) psychological states as opposed to noninternal ones suffice for explanation in psychology. Especially, feedback-based actions are argued to require indispensable reference to noninternal explanantia, often to explanatory common causes. Thus, to the extent that methodological solipsism is taken to require the truth (...) of the Explanatory Thesis, it, too, can be regarded as untenable. (shrink)

Noonan's arguments against methodological solipsism ("methodological solipsism," "philosophical studies" 4, 1981) assumes that mental states are individuated by (russellian) content; this assumption entails that narrowness and wideness are intrinsic to mental states. I propose an alternative "extrinsic" reading of methodological solipsism, According to which narrowness and wideness are modes of attribution of mental states, And thus reject the doctrine of individuation by russellian content. Noonan's arguments fail against this version of methodological solipsism.