The paper seeks to contribute to the discussion of Hume's theory of personal identity, by examining a conflict regarding the vivacity of the self in his writings about sympathy. Although the mechanism of sympathy supposes that self is the liveliest perception of thought, when we consider sympathy through the perspective of the ‘desire of company’, we find that self lacks vivacity and, without alterity, it would be in reality nothing. Our objective is to present the conflict and show that, far (...) from being a contradiction in Hume's thinking, it is consistent with how the philosopher conceives personal identity as a product of imagination, that is, a perception that, like any other, exists within the flow of perceptions. (shrink)