Andy Clark has a bold - no, a really bold - thesis: our minds and our selves are not limited to our 'biological skin bag' called the brain or even our biological selves. We, in reality, are cyborgs in the sense that we are merging with a world of technology so much that where 'it' begins and 'we' end is becoming a fuzzy line - a line that we might be best to dispense with altogether. Quite literally, our brains can be called only part of our mind.
Curious yet? I know I was. So, here is my experience with the book: I read it, raised my eyebrows quite a bit (and mumbled some under-my-breath "Wow"s) and remained unconvinced that we are LITERALLY cyborges in the sense that Clark has in mind. Whatt I did come away with (the reason for the 4 stars) is a new lens with which to view the world. Every time I see someone talking on their cell-phone, saving data to their hard-drive for retrieval later on, or even driving their cars, I will now be asking questions like, "How much can this piece of technology be said to add to her nature?"
Still sounds weird? Clark's method of argument is to argue that the brain - what we sometimes call the seat of the self - is suprisingly malleable and accomodating to outside influences. Even our own image of what is and is not 'part of ourselves' is radically flacid. His case is suprisingly powerful. For an appetite whetter, though, just think of yousrelf driving a car. When you are driving, you usually do not think about driving as such: "I need to turn left, and to do that, I move my steering wheel left which moves this external car, with me in it, left." You almost feel like the car and the steering wheel is an extension of you in that controlling the car becomes 'second-nature' - turning left becomes as natural [check the metaphor] as moving your left arm.
From here, Clark talks about how it is human nature, seemingly, to use tools to aid us: from pen and pencil to store thoughts, to wristwatches helping us coordiante time, to the internet allowing us to communicate farther and farther distances - that's just what we do; adding that the 'we' in that sentence is no longer simply biology, but actually includes the technologies that we use.
All this, to me, was convincing in the sense that there is much more continuity between our brains and technologies than we usually realize, and that they do help change our natures. But, it does not follow that because the self is a concept that easily adapts to technology (that is becoming constantly smaller, more invisible, and human friendly) that this means literally that we now have 'cyborg' natures: that we are not still biologal selves with ever-increasing relationships with technology. If Clark used the phrase 'our cyborg natures' metaphorically maybe I could go along (and as convincing as the book is, probably would have). But he means it literally, and he is not as convincing as he needs to be.
Buy and read the book though. Lilke me, you may remain unconvinced by his larger point but you might well be swayed by some of his smaller points. Really learning to appreciate how integral a part of our goals, natures, and every-day lives technology is, is an exciting thing. Postulating how technology could change us in the future and even eradicate or alleviate many of our limitations is not something to be feared or scoffed at, but to be embraced.