The aim of this paper is to scrutinize active externalism and its repercussions for externalism about mental content. I start from the claim that active externalism is a version of content externalism that follows from the extended cognition thesis as a thesis about cognitive vehicles. Various features of active content externalism are explored by comparison with the known forms of passive externalism – in particular with respect to the multiple realizability of the relevant external content-determining components and with respect to (...) mental causation. A crucial result is that social externalism is already a version of active externalism. I conclude with a first sketch of a general account of meaning inspired by extended cognition: a use theory supplemented by a functional-role account. (shrink)