I am sorry to be so blunt about this, but previous reviewers Sierra and whomi do not appear to have really grasped Winnicott's work in this book (Sierra really has no clue at all). I have to respond at some length. But better to just read the book.
Winnicott (henceforward DWW) creates--in an enormous leap away from Freud--a vision of the complex and beautiful relationship of the infant and primary caregiver. In fact he speaks of the "mother infant dyad," rather than two separate persons during the first few months of life. From this union, if all goes well, the child gradual emerges and develops a sense of self through a process of disillusionment by the mother, in doses the infant can withstand.
As this occurs, the child symbolizes the lost union with the mother in what DWW calls "transitional objects" and begins, with the comfort of these objects, to begin to play in what DWW calls the "potential space." We might call it the realm of culture, of love, and of religion. Only with successful caregiving does the child have a chance to fully develop as a person, and DWW shows, in loving detail and case histories, how this happens through the devotion of the mother.
This is why DWW's work is vital not merely to psychoanalysts, but to every person on this planet. His work has influenced two generations of therapists, theorists, and educators and, indirectly, every one of us. Further, his work has increasingly been supported by developmental insights gained from attachment theory and other experimental and verifiable studies.
I don't normally write reviews on amazon.com, but I could not let foolish misreadings by other reviewers stand unchallenged. Sierra's attitude is not only condescending, it is lazy. Enough said. As for whomi, I appreciate the thought there, but DWW *does* allow for gradual disillusionment through experience of the external world. If whomi missed it that does not mean it is not there. As for using Derrida to read DWW, I imagine that is useful. Go to it, if you like. But let's not forget that the work of Lacan is inconceivable without DWW, and the work of Derrida inconceivable without Lacan.
DWW indisputably and deservedly stands as one of the most influential psychological thinkers of the 20th century. Further, his use of language is simple and yet always provocative, finding new depth and meaning in the simplest of words.
Please consider reading DWW and judge for yourself.