Some time ago I was doing a longform series on Exocortex, my cognitive prosthetic system. I left off with some fairly broad and open-ended questions about the implications of such a software system for identity and agency. Before I go on, though, I think I'd better define some terms. Identity is one of those slippery concepts that you think you get until you have to actually talk about it. One possible definition is "the arbitrary boundry one draws between the self and another," or "I am me and you are you." A more technical definition might be "the condition or …