Since mental ambivalence is irreducibly plural, it appears that persons cannot be inherently unitary; unity, rather, might be normative, an aim or norm of harmonious unity which is always at work. I argue that normative unity requires the person's unity in plurality in the sense that actions, attitudes and other engagements are connected and connectible; and that that such connections encompass ambivalent engagements. Thus, accounts of the person in which ambivalence serves merely as a point of departure or as the failure of the pursuit of harmony cannot be right. By contrast, Freud's account of personhood and ambivalence shows that ambivalent engagements manifest the unity of persons and allow for action, creativity, and emotional involvement. Despite having been interpreted as reducing the person to several quasi-personal independent parts, Freud's person is in fact unitary, and his ambivalent engagements are regulated by an ideal of harmonious organization. The paper combines a philosophical analysis with the study of Freud's writings