I progress slowly through Freedom Evolves as bedside reading. Still fighting the common resistance to determinism Dennett calls incompatiblism, he now demonstrates that the naturalist Robert Kane's hope of introducing an indeterminate element into decision making is based on defining a container where the indeterminism can act. Dennett carries this approach to the conclusion of a small pearl that grants free will: "If you make yourself really small, you can externalize virtually everything." (p122) He then draws the inevitable comparison to the Cartesian ghost in the machine, and asserts that your mind, your consciousness, your identity includes your entire brain.
Here, I think there's a potential weakness in his treatment. Why should the differentiation between brain and body be the magic delineation? Dennett argues that the internal self (the concept of me) is a nebulous construction of consciousness, defined arbitrarily and subject to flaws (as in the case of MPD). He fails, though, to extend this to the external self (the concept of you) and considers "you" to be your brain, or at least the neural patterns embodied by it.
From my amateur philosopher's armchair, it appears naive to consider "you" as a wrinkly grapefruit of neural tissue, without considering the rest of the nervous system, and therefore, the rest of the body, and the environment that acts on that body, etc. The current temperature, light levels, audio atmosphere, and such will impact my decision making. I might not be motivated to finish writing this sitting at the train station were it not for the isolation of having the iPod turned up. So, isn't the music a part of "me"?
This is a dangerous path, for I could continue extending until the metaphorical butterfly flapping its wings in England four decades ago is a part of "me". But Dennett seems to be saying the magic pearl boundary is too small, and including the whole world is a libertarian straw man argument, so he needs to defend his arbitrary boundary placement.