Iris demented
The big-screen stars (Broadbent as Bayley, Judi Dench as the elder Murdoch, Kate Winslet as her younger self) are winning and impressive through sheer screen presence here, and Broadbent really is wonderful in what may be the true central role in the film. And Hugh Bonneville is very good as the younger Bayley, in part because he is so persuasively a younger version of Broadbent as well.
Still, it’s too easy to find yourself wishing that there were more Iris in Iris. The quasi-Proustian intercutting of youth (Winslet) and old age (Dench) generates a certain pathos, but the more "Murdochian" of the two (Dench) is in a sense wasted in a role that is primarily about the relative absence of Iris Murdoch in the later parts of her life.