SummaryStarting with Descartes, epistemology has been almost entirely based on first person knowledge. We must begin, according to the usual story, with what is most certain: knowledge of our own sensations and thoughts. In one way or another we then progress, if we can, to knowledge of an objective external world. There is then the final, tenuous, step to knowledge of other minds.In this paper I argue for a total revision of this picture. All propositional thought, whether positive or skeptical, (...) whether of the inner or of the outer, requires possession of the concept of objective truth, and this concept is accessible only to those creatures in communication with others. Third person knowledge – knowledge of other minds – is thus conceptually basic. But such knowledge is impossible without knowledge of a shared world of objects in a shared time and space. Thus the acquisition of knowledge is not based on a progression from the subjective to the objective; it emerges holistically, and is interpersonal from the start. (shrink)