This chapter discusses the time-honoured question as to whether or not we should credit ourselves with two distinct 'lives'. One consisting in the gross movements of the parts and particles of our bodies, and the other consisting of much more impalpable, ghostly and secret changes, which not only elude outside observers, but also prove somewhat elusive even to those to whom they actually happen. The chapter considers how, if we admit two such lives, we should conceive them as related to each other, whether as the histories of distinct agents, or of the same agent differently regarded. Finally, one should conceive of them as impinging on each other and modifying each other's course of development. The chapter explains how we should let out psychophysical talk be affected by facts about the happenings in out brains, of which we now only know enough to confuse us, but concerning which we may have better knowledge in the future.