Once again I find myself disagreeing with tags and ratings. In my opinion, the book is both well done, very timely and an important contribution. For me, it contained clear-cut explanation of several things I have often wondered about. I suspect that the reason the book has such low rating is that she blows holes in a good many cherished ideas. I am glad I read it and I wish she would write a follow up with a view of more recent works. The book was written in 1969, so it is missing recent works. Perhaps that is one reason why one tag calls it out-dated, but certainly as a view of the history of this genre the theories are good, I would just like her views on what has happened since 1969. Highly recommend. ( )