Discusses the concept of boundaries, and describes their implications for sleep disturbances, psychopathology, physical illness, creativity, career choice, and brain biology
Hartmann is a good writer. People with mostly thin boundaries are painters, writers, counselors and other people who need to be open to inspiration and creativity. People with thick boundaries are salespeople, naval officers, lawyers, etc... There are also people with thick inner and thin outer boundaries such as some Catholic-trained counselors. Successful artists may have thin inner and thick outer boundaries. He also relates the "Boundary Questionnaire" to certain personality tests: the MMPI test, the Rorschach test, and hypnotizability test. He also relates the questionnaire to psychopathology.
I guess the ideal is someone who can achieve thin inner boundaries and thin outer boundaries. The only time I can think of that had people like this was the Renaissance. Strangely, few Catholics or artists have need of Freud or Jung. Da Vinci, a Catholic artist, seemed to be the closest to having both thin inner and thin outer boundaries. Sadly, some denominations ban all art from their places of worship. Consequently, they often need a helping hand from someone in the "helping" professions.