I was doing some research on schizophrenia for a little project on the side and came across some of his articles. He developed a systems theory of family so I'm hoping some of the folks who do research in that area can tell me what's in and what's out these days, lol. If you are not familiar with him, check out his wikipedia page. He initially focused on anxious attachment relationship between schizophrenics and their mothers but then moved on to develop a theory about other dyads and also triads in the family and importance of differentiation of the self. He introduced other concepts too, some of which are mentioned here:
http://www.psychpage.com/learning/library/counseling/bowen.html
http://www.psychpage.com/learning/library/counseling/bowen.html