This paper critically evaluates fundamental concepts of object relations theory with reference to both cognitive theory and developmental theory. For example, Melanie Klein's view that objects are a permanent unchanging substratum of personality acquired in infancy is challenged as placing too much emphasis on an inner world and too little on the external world and its ongoing influence. While object relations theory makes a noteworthy contribution to a psychoanalytic view of personality, in the opinion of the author it overlooks important observations from cognitive and developmental psychology.