There is a philosophical temperament that sometimes surfaces here, that indeed thinks that anything less than the whole truth must be not only partial, but just because of that somehow false....It derives from Plato's idea that the lover of wisdom, when he gets out of the cave into which the rest of humanity is confined, not only learns more but also learns that what the others take for truth is in fact illusion. The Platonist Iris Murdoch was an artful exponent of this implausible line, constantly denigrating everyday life in the name of something higher.
The only evidence for this last sentence is a footnote to Murdoch's Metaphysics as a Guide to Morals. This last sentence pulled me up short when I read it; it sounded so utterly implausible a claim about Murdoch that I went back and re-read the whole of MGM to see if I had missed something. I hadn't; there is no trace of what Blackburn says she was "constantly" doing. In fact, you get passages like this, in Chapter One:
However, if it is to enlighten us, Plato's attack on art must be seen in the context of his whole moral philosophy. Life is a spritiual pilgrimage inspired by the disturbing magnetism of truth, involving ipso facto a purification of energy and desire in the light of a vision of what is good. The good and just life is thus a process of clarification, a movement toward selfless lucidity, guided by ideas of perfection which are objects of love. Platonic morality is not coldly intellectual, it involves the whole man and attaches value to the most 'concrete' of everday preoccupations and acts. It concerns the continuous detail of human activity, wherein we discriminate between appearance and reality, good and bad, true and false, and check or strengthen our desires.
Which is exactly the opposite of what Blackburn attributes to her. Murdoch's view is that consideration of the true, the good, and other 'ideas of perfection', far from leading us to denigrate everyday life, leads us to find more of value in it. Far from making us dismiss the partial, it gives us a richer sense of the detail of the parts, because it puts them in a context. And what is more, Murdoch insists on more than one occasion that 'something higher' is part of our everday life -- our everyday lives are partially structured by the magnetism of the good and the true. Indeed, this very point is a major part of the argument of the book.
I'm rather mystified as to how Blackburn could have come to attribute to Murdoch the exact opposite of the view Murdoch actually insists upon. It's almost as if he had in mind a caricature of Platonism, decided he needed an actual Platonist for an example (the other example he uses is British Idealism), thought, "Who is a notable modern defender of Platonism?", and said, "Oh, yes, Iris Murdoch, I'll put her down as an example," without any regard for how Murdoch herself fit the caricature. Or conceivably he confused Murdoch's view with fragments of other philosophers whom she discusses. But it's a serious misreading.