Summary: Socrates posed several questions, one of them being 'what is good?'. As thinking beings we have purported through the milleniums to think about this question, and many more, and specially tried to relate such intellectual activities to the 'real' world of our everyday practical lives.
Iris Murdoch is one of those intellectuals of a group (my hypothesis) concerned with morality and in particular, questions to do with moral philosophy in the broadest sense. Others in that category vary from Nietzsche, J. M. Keyenes, Et cetera to major theological thinkers and texts.
Reading the 'Metaphysics' brings one closer to Murdoch. One begins to understand better that she did her philosophy through her stories. 'Afterall, aren't we all telling stories?' To paraphrase one of her characters from an earlier novel. She was concerned with re-discovering the roots of some of the bigger questions that any thinking person might ask; and in this book, she brilliantly, clearly, wittily follows through to their uses, changes, revelations - weaving her own genius throughout. I was reminded of her description of the fictious philosopher in 'The Philosopher's Pupil' when she writes, 'all the books are in him now'; I felt, that all the books were in her, and all I had to do was to read this one person's insights from her various narratives and I might just glimpse a 'truth' myself.
Indeed, seriously reading 'Metaphysics' must be, in the beginning, a pursuit to know oneself. However, in the end, turns towards the very opposite: not a deconstruction, nor a rebuilding of the self; but rather a 'blowing out'. A realisation of the grativy of people, even morally 'good' people, to draw towards them a veil of memorabilia, illusions, desires, regrets, life-denying, selfishness. Such a realisation would require a 'radical' rethinking of the self and it's senses of, and de/re-construction of morality in relation to the world around us.
I do not think that Murdoch was in any way an enlightened being, though she pursued that path seemingly endlessly and exhaustively. Though without recourse to Buddhist 'ideology', but rather through rational contemplation of her own.
If you want a fresh perspective on themes such as art, religion, morality, et cetera and how such abstract notions relate to the practical world where the Self is the King/Queen, then this is in fact a great starter. Murdoch allows room to stop and read up on the original texts of such thinkers as Plato, Arthur Schopenhauer, Simone Weil, Et cetera; in order to get a better understanding of her interpretations.
Indeed, this text, along with 'Sovereignty of Good' makes perfectly clear some of the insightful conjectures upon society that she makes in her novels. In fact, her novels are the real philosophy, me thinks. Her laboratory as such.
'The Sea, The Sea', which won the Booker prize in its time, is a good book to begin Murdoch with. Even if you find it disturbing, yet want to discover more about the genius of Iris Murdoch (who has influenced/inspired such modern thinkers as Karen Armstrong, author of 'A History of God', et cetera), read 'Metaphysics as a Guide to Morals' - and let the wisdom in ^_^