One of Osipow’s major contributions to the fields of vocational psychology and career counseling continues to be his efforts to describe, evaluate, and compare theories of career choice, development, and adjustment. Osipow’s interest in this topic spans his career in counseling psychology. He began his reading and reflection on career theory when, as a graduate student at Syracuse University in the late 1950s, he wrote a term paper on the topic. After completing his doctoral studies, Osipow worked in the Counseling Center at Pennsylvania State University (1961-1967) which was directed by Donald Ford who had written a book on theories of counseling and psychotherapy (Ford & Urban, 1963). Osipow’s relationship with Ford, along with the intellectual climate at Penn State, nurtured Osipow’s ambition to expand his term paper into a textbook that organized and explained the theories of career development. That book, Theories of Career Development, first published in 1968, is now in its fourth edition (Osipow & Fitzgerald, 1996). Osipow’s (1968) book along with Crites’ book on Vocational Psychology (1969) helped crystallize vocational psychology as basic science discipline, distinct from the applied psychology of career counseling. Furthermore, Theories of Career Development became the standard textbook for generations of graduate students enrolled in career counseling courses.