The human body is a wonderful machine. But a machine nonetheless. I think that people who try to convince you that there is something other than the physical meaty parts of your body are trying to take away from the wonder that is the human machine. When you start to explore how amazingly intricate each part of the human body is, and how it has evolved, you really get a sense that nature has put a lot of trial and error work into us. Evolution has produced something that is incredible. We are far from perfect however. If you are a male, and live long enough your chances of getting prostate cancer are better than you would like to think about.
The human machine breaks down. What I find really interesting however is how our brains seem to be very complicated organic computers. I found this and this. Now you might think that a drug that turns you into a compulsive gambler or sex addict might make for a good time, at least until you came down off of it. However it shows perfectly that giving the right chemical inputs you get the proper behavior out. Who knows where this will take us.
We could be headed for a dark Orwellian world of control where we are fed our daily trust spray so that we wont fight the evil overlords. Or we could be headed towards complete mastery of the human hormone system and with it the control of most illness. I guess it all depends on what we want to use it for. And if you are wondering, yes this is the sort of thing I think about when I am bored.