@Razzleg,
First, I don't think Joefromchicago is a Utilitarian. And even if he were, it certainly isn't "a hardline Utilitarian answer" to point to Rawls's Original Position. Second though, let me address your specific questions:
Razzleg wrote:Thomas, specifically: my standard response to a lot of utilitarians regarding your response, were they to make it, would be: can you explain the maths involved?
Basically, yes. Maximizing for utility comes down to finding the best possible tradeoff between efficiency and equality, both of which we can measure in quantitative terms. Granted, Utilitarians disagree about the specific quantitative terms to use. They also disagree about the proper rate for trading off efficiency against equality. That's why I'm hedging my "yes" to your question with the word "basically". But even so, our intellectual grasp on the concept of utility is at least as tight as the medical profession's grasp on the concept of health. So if medicine is rigorous and realistic enough to work as a science, Utilitarianism certainly is rigorous and realistic enough to work as a political and moral philosophy.
Razzleg wrote:And can you describe the specifics regarding the institutions you would design to optimize human happiness, assuming that you wouldn't have the opportunity to design (or define) humanity?
My social contract would start with a presumption of anarchy, because I expect, as a rule, that
laissez-faire leads to competitive markets, which in turn maximize the general welfare. But the rule has exceptions. Market failure does happen, in ways that economists understand well enough for practical purposes. Therefore, I would then add public interventions that are narrowly tailored to correct those market failures. This includes government itself, which is a source of both positive externalities, negative externalities, asymmetric information, and monopoly power. That makes government an intellectual hairball to deal with, but I think Utilitarians have the intellectual tools to untangle it.
Razzleg wrote:It seems to me that a lot of your response could only be proven by "trial and error", and that thus you are only half (give or take) right.
I agree, but I don't see how that's a philosophical problem. Why shouldn't the people behind Rawls's veil of ignorance have a library? Why wouldn't they inform their decisions by reading up on the practical consequencees of particular social institutions?
Razzleg wrote:(In other words, would the thought experiment described actually make you a utilitarian, or has experience, and methods to make it seem correct, deemed that the appropriate response is utilitarianism?)
It would
make me a Utilitarian. I'm egoistic. I'm rational. I want to maximize the expectancy value of pleasure
I experience throughout
my life. The library I just mentioned has informed me about the world I'm about to be born into, so I know approximately how it works. But I don't know my future place in the society I'm creating. Hence, the best I can do for myself is to create one that maximizes the average surplus of pleasure over pain, given the realities of the world. As it happens, that's the goal of Utilitarianism, too. Observe, however, that my Utilitarianism would be a conclusion of the thought experiment, not an assumption.
Razzleg wrote:In a related side note, it seems to me that most utilitarianism is rooted in a belief in an "objective quantifier", or a "metaphorical equalizer" within most situations. Is this a mistaken belief, and how so or how not?
I can't answer that question, because I have no idea what the terms "objective quantifier" and "metaphoric equalizer" mean.