Karen Horney (1885-1952) was a German psychoanalyst and psychiatrist, who is sometimes classified as "Neo-Freudian," although she questioned many of Freud's theories (particularly about psychosexual development).
She states in the Introduction to this 1942 book, "It has always been regarded as not only valuable but also feasible to 'know oneself,' but it is possible that the endeavor can be greatly assisted by the discoveries of psychoanalysis... It is the object of this book to raise this question seriously, with all due consideration for the difficulties involved. I have attempted also to present certain basic considerations regarding procedure, but since in this field there is little actual experience to serve as guide my purpose has been primarily to raise the issue and to encourage endeavors towards a constructive self-examination rather than to offer clear-cut answers."
Here are some quotations from the book:
"On theoretical grounds, then, I see no stringent reason why self-analysis should not be feasible. Granted that many people are too deeply entagled in their own problems to be able to analyze themselves ... all of this is no proof that in principle the job cannot be done."
"Briefly, the adult merely adjusts his behavior while the child changes her personality."
"Self-analysis is an attempt to be patient and analyst at the same time..."
"The analyst's general task is to help the patient to recognize himself and to reorient his life as far as the patient himself deems it necessary."
"The method in self-analysis is not different from that in work with an analyst, the technique being free associations."