Scott Campbell has recently defended the psychological approach to personal identity over time by arguing that a person is literally a series of mental events. Rejecting four-dimensionalism about the persistence of physical objects, Campbell regards constitutionalism as the main rival version of the psychological approach. He argues that his “series view” has two clear advantages over constitutionalism: it avoids the “two thinkers” objection and it allows a person to change bodies. In addition, Campbell suggests a reply to the objection, often raised against views such as his, that thoughts must be distinct from their thinker. In this paper, I argue that Campbell's responses to the “two thinkers” and the “thoughts/thinker” objections are unsuccessful. Furthermore, his reply to the latter leads to four-dimensionalism of the kind he wanted to avoid – and this view too allows a person to change bodies. Moreover, I argue that it speaks against the series view that generalised versions of it fare much more poorly than do generalised versions of constitutionalism and four-dimensionalism.