You are given a choice between two rewards. The first reward is to be twice as intelligent as you are right now–you will be able to read twice as fast and remember twice as much, the size of your vocabulary will double, and you’ll be able to solve intellectual problems with twice your current aptitude. The second reward is that you will never again feel sick (even when you are) and you can always be whatever weight you want, regardless of what you eat or how little you exercise–you can simply imagine the body you would like to have and that is the weight you will magically become.
Which reward do you choose?
Well, the mind-body problem is a classic one in Western philosophy, and it shouldn’t be easy to pick between the two. In this case, it is. Here’s why: the body reward just isn’t that great, while the mind reward is.
The body reward really isn’t much of a reward. On the face of it, never feeling sick sounds great. No more coughing, sneezing, itching, and so on. Except…pain serves a purpose. Just look at the cases of congenital analgesics for an illustration. Klosterman is careful to mention that you are still getting sick, you just don’t feel the pain of the symptoms. Um–that could be really bad.
How many people have discovered a cancer just early enough when they notice a small sensitivity, as if slightly bruised? And what about vomiting–vomiting can save your life if it means the ejection of an ingested poison. All in all, this part of the reward seems ill-conceived to the point that it could be dangerous. Plus, mortality is part of being human–are you ready to distance yourself from humanity to that extreme degree?
The other part of the question isn’t really worth talking about. It is obtainable (for most people) without any sort of magic, difficult though it may be. Moreover–despite the social stresses placed upon body type and image–your body type really shouldn’t matter that much, as long as you’re healthy.
On the other hand–immense intelligence. I’m not exactly sure how to measure intelligence as it is discussed here, but doubling it has to be extremely significant. This increase is sure to have numerous positive implications. If you’re of average intelligence now, it means definitely above-average intelligence, which you may be able to parlay into a higher-paying job or even a happier life, according to some psychologists. If you’re already of above-average intelligence, you could be rocketed into genius status. It’s unclear whether this is likely to make you any happier–I can even see how it would accomplish the opposite, as your great intelligence would alienate you from much of human society. Still, great intelligence can a) increase your happiness and wealth, and b) increase your ability to help others (through greater ingenuity, etc).
I think mind is almost certainly the better choice.