The emphasis, de-emphasis, or no emphasis of 20 dimensional categories (e.g., unconscious processes, purposive behaviour, early development) were compared by hierarchical cluster analysis for 15 formal personality theorists (e.g., Freud, Rogers, Bandura). Results uncovered three relatively unique families of theorists with 100% reclassification: (a) Adler, Erikson, Freud, Horney, and Murray were grouped as Neo/Freudians; (b) Allport, Bandura, Jung, Kelly, and Rogers as Phenomenologists; and (c) Cattell, Dollard/Miller, Eysenck, and Skinner as Empiricists. The first of two discriminant functions was based on positive loadings from each of purposive behaviour, multiple motives, and self-concept; and successfully discriminated among all three clusters (Neo/Freudians exceeded the Phenomenologists who exceeded the Empiricists). The second function was based on positive loadings from each of developmental continuity, early development, and learning; and negative loadings from purposive behaviour, uniqueness, organismic focus, and ideal self. This function successfully discriminated between the Phenomenologists and both Empiricists and Neo/Freudians (who did not differ).