E valuating and treating personality disorder (PD) begins with an understanding of personality. However, since the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III; American Psychiatric Association, 1980), the modern editions of the DSM have defined PD syndromes by a symptom criterion-count method rather than by explicit focus on personality functioning. In contrast, the Alternative DSM-5 Model for Personality Disorders (AMPD; 5th ed.; DSM-5; American Psychiatric Association, 2013) organizes features of personality into a hybrid categorical-dimensional framework for PD diagnosis. With the emphasis on personality, the complementary lenses of different paradigms of personality theory and personality science become inherent in AMPD diagnosis. But, we ask, what is personality?Theorists from Allport (1937) to Kernberg (2016) have viewed personality as a dynamic (nonstatic) synthesis of aptitude, belief, temperament and trait, and implicit habit of mind that participate in expressing core life themes associated with personal history. Genetics and constitutional givens, experience and history, and personal agency are woven into a sense of self and identity. The personologist Dan McAdams (1995) asked, "What do we know when we know a person?" (p. 365). For McAdams ( 2015), the answer is plural, as he relies on the metaphors of actor, agent, and author to define qualities needed to know a person; these include (a) observable actions reflecting temperament and trait, (b) characteristic adaptations expressing internalized patterns or schemas of agentic coping and adapting, and (c) guiding self-reflexive themes