As this is from Murdoch, the book gets five stars. The next question is, how does it compare to her other works?
Unfortunately, not very well. I don't usually say this, but the book would be much improved if it was twice as long. In the book's 150 pages it rushes from one drama to another with not enough quiet moments or lead in or build up. It needed more room for people to have normal conversations and to give support for the high points of the book. Oddly enough, the descriptions of the natural world and the house hold surroundings get the usual lush and lengthy treatment, while the actual character interactions and dialog are these brief, sharp engagements. There are lots of conversations where people who barely know each other have short, impromptu exchanges about the upper reaches of metaphysics. It is a bit like reading Rand, except that the speeches are 1/50th as long and are in Murdoch's code rather than Rand's. Alternatively, it is like reading straight Simone Weil, rather than Murdoch's more usual Weil as adulterated by story and character. As is, The Italian Girl ends up being something of a parody of an Iris Murdoch novel.
Despite all of the above, The Italian Girl is not devoid of things to love. The protagonist is a standard Murdoch type, but he is still delightful in his quiet horror of marriage, messes, dirt, grease, alcohol, wetness, etc. etc. Otto is a wonderful pig, and the way he shovels various raw ingredients into his mouth and fails to notice hunks of butter about his person are great. And at least at the start Murdoch does a good job of quietly undercutting and satirizing her characters and their constant drama. In my favorite books she does this throughout the story, and this constant counterpoint is both part of her program and helps makes the drama and high abstractions more palatable. Also, as usual Murdoch is never afraid to throw a story on its head. It's a bit like reading a Philip K. Dick in that the world can shift rapidly and unpredictably in the space of sentences. Several of the shifts are standard Murdochian ones, but there is still a great deal of surprise.
I give it 2 Tallis'.