I first heard of this American psychiatrist from my parents who had been in a neighborhood discussion group with one of his followers, Bob Kvarnes, who introduced himself as "a psychiatrist, but I am not a Freudian: I am a Sullivanian".
Sullivan was a child of Irish immigrants from the potato famine, in fact, an only child of parents who had twice miscarried. He grew up poor in an anti-Catholic town, and troubled by a vast social difference between his parents' families. Somehow he got through his own childhood troubles and into the field of psychiatry. In this field, he made so many innovations that everyone has felt their influence.
Not me, you are thinking; I never heard of him.
But you have heard of self-esteem, right?
Right, you may say, but if he is where that idea came from, I wouldn't give a nickel to learn anything more about him.
Here's what's so interesting. Probably every single one of the American psychiatrists that you have heard of, -- Erik Erickson, Eric Fromm, Karen Horney, the list goes on and on -- was once a co-worker or student of Sullivan and made a substantial reputation on one of his ideas. Wouldn't it be interesting to study the single mind where all those ideas came from and see how they were integrated within one perspective? For that matter, wouldn't it be interesting to see a trenchant criticism of the limits of Rogerian psychotherapy from one of his peers? Sullivan is your man!
Furthermore, at the end of his life, Sullivan somehow turned again to the Church. I do not know the details of this, only that he managed (very carefully) to arrange for a Catholic funeral, which was boycotted by many or most of his psychiatric colleagues. It is partly, but not only, in view of this final act that we are justified in looking at his entire career as a movement through the minefield of psychiatry towards the truths of the Church, to which he was introduced in childhood.
Anyway, his great contribution to psychiatry was to move psychiatric counseling away from the Freudian model of fitting all difficulties into a single pattern of perverse sexuality. Instead, Sullivan viewed his client as a person with "problems in living", especially in interpersonal relationships, even such problems as we all have. ("We are all more human than anything else," he said again and again, emphasizing the simply human nature of various types of mental disorder.) He was the first to work successfully with schizophrenics, and had many insightful critiques of the Freudian approach which was completely helpless before this "difficulty in living". Freudians therefore regarded schizophrenia as one of the worst diseases, rather than merely the disease that best exposes their weakness.
I have found my introduction to this man wholly fascinating and look forward to reading more. If you are required to take a course in psychology, see if you can't do an independent study on Harry Stack Sullivan. You may learn something really useful.
Harry Stack Sullivan Interpersonal Theory and Psychotherapy by F. Barton Evans III