Anthony Kenny suggests in his stimulating paper Wittgenstein's Metaphysics of Mind that Wittgenstein's attack on Cartesianism is driven by a metaphysical view similar to Aristotle's theory of potentiality and actuality. He recommends using the threefold distinction between possessor,vehicle and exercise of an ability for interpreting Wittgenstein's view of mental events. As a heuristic device, this may prove useful, but I doubt that from this proposal there will emerge anything that may legitimately be called "Wittgenstein's Metaphysics of Mind".