The amoral crusader returns! (thats me…)
To answer your original question James, I think the logic falls apart at the point where you use the term “objectively advantageous.” I would argue that nothing in reality can be said to be “objectively advantageous” without referencing a particular goal. In your health food example, if you are saying that the fact that the food improved the persons health (regardless of his opinions or desires) means that the healthy food is “objectively advantageous” then this statement would be incomplete in its current form and thus inaccurate. While it may be true that it is “objectively advantageous” to eat healthy foods IN ORDER TO BE HEALTHY, It is not “objectively advantageous” to a body to be healthy. NOTHING is “just objectively advantageous.” It is only “objectively advantageous” to be healthy and thus eat healthy food if you reference a particular goal for which being healthy IS ADVANTAGEOUS. For example: “In order to have more mobility, it is very likely that being healthy is objectively advantageous” or “in order to prolong your existence in the current ecosystem, it is very likely that being healthy is objectively advantageous.” But, for example, if your goal is to prevent inertia: “in order to prevent inertia, it could be argued that becoming morbidly obese is objectively advantageous.”
Now before you go and ridicule my example of a goal for which being healthy is not advantageous, consider the nature of evolution. Evolution is full of cases of mutations that seem dis-advantageous in a particular set of circumstances, but turn out to be essential to that organism’s survival when the ecosystem changes. You can think up the most ridiculous seemingly dis-advantageous case, and with a good imagination someone could come up with a plausible set of circumstances that would make that case advantageous. The theory of evolution is designed to account for such cases. It is entirely plausible that becoming morbidly obese could become extremely advantageous given the right set of circumstances.
Importantly: Bear in mind that in the above description of evolution, the assumed goal is prolonging the survival of a species. Thus cases are said to be advantageous when they achieve this goal. But who is to say that it is objectively advantageous to a species to prolong its survival? That is not built into the definition of advantageous. From google dictionary: “advantageous: involving or creating favorable circumstances that increase the chances of success or effectiveness; beneficial.” There is no mention of which goal it has to increase the chance of success or effectiveness for. It is completely context dependent! I cannot even logically say that my own survival is objectively advantageous.
Up to this point I have been trying to illustrate the nature of the term “objectively advantageous.” I think It simply does not make sense to say that something is “just objectively advantageous” without referencing a particular goal. The conclusion from this is that ANYTHING can be effectively, logically argued to be “objectively advantageous” if you pick the right goals. To which you might argue that “it is ridiculous to think an individual or a society would choose “prevention of inertia” as a primary goal of behavior.” Individuals and societies tend to share common goals. Such as Anon’s assertion that all sentient organisms seek happiness. While I disagree that ALL organisms do this (you never know what kind of fucked up wiring an organism might have - happiness may not be their primary directive biologically and sometimes some ideas can become primary directives to a point where it would be difficult to categorize their behavior under the category “pursuing happiness”) it IS safe to say a very large proportion of humanity have very similar fundamental goals. But then the fact that most people feel this way does not an argument make for its objectivity.
By using the term “objectively advantageous” you have shifted the moral question to “what are good vs bad goals?” instead of “what are good vs bad actions?”
Your argument about calculators and that people are too dumb to do math but yet believe they can do complex moral calculations falls apart when you talk to an expert philosopher (thats me! ) When you talk to an expert mathematician he/she may be able to answer your difficult math question objectively. When you talk to an expert philosopher, or at least a thoroughly logical philosopher, I think most of them should see the reality as I see it. The reality is this:
There is no such thing as objective value in the universe. The universe, as far as we can currently tell, is just stuff bouncing around. Value is created by minds. This should inform you about the nature of morality. Morality should be considered as a different variation on a concept we seem much more willing to accept as purely subjective. Beauty.