Divided into two parts, Pitson's study follows Hume's important distinction between two aspects of personal identity: the "mental" and the "agency". The first part discusses Hume's conception of the mind as a "bundle" or "system" of perceptions and explores Hume's position on the traditional mind/body problem. In the second part Pitson examines a range of topics including Hume's treatment of character, the relationship between human and animal nature, and the nature of agency.