Fun, yet disturbing. Delightful, yet deep. Andy Clark combines a broad array of insights and stories into a charming, yet profound, excursion into what it means to be human as more and more we rely upon -- and may even be coupled to -- our technology. What will it mean to be human as we modify ourselves more and more through artificial means. We have already started: we can't exist without our external technologies for food and clothing, transportation and strength. Books, calculators, and computers are becoming indispensable aids to cognition. Now we are adding implants, chemical enhancers, even electromagnetic ones. Some are necessary for medical reasons, but when the medical cure becomes superior to the biological original, what then?Clark covers all these topics with verve, humor, and depth -- after all, he is a philosopher by profession. I want to teach a course using it. I want to tell my friends. The neatest part is that it is both fun and deep, a hard trick to pull off, but he managed wonderfully. I read it in a day, but I know I will return to it often.