The futility of utility

Utilitarianism is one of the many desperate attempts to replace a moral reality grounded in cosmic order (the Tao, the Dharma, Maat, the Way of Heaven, etc.) with one invented by humans. The calculations it suggests we should perform are absolutely impossible. Even if it were possible to quantify "utility," in a way that allowed interpersonal utility comparisons, the utilitarian calculus supposed is still ridiculous: an agent would need to know exactly how their action would impact every single other person in the world, for the rest of time, so long as the world exists, to correctly calculate whether their action "maximized utility" across all humans (or all living beings, if one is an animal rights sort?).

Pretty obviously, no one can actually perform anything remotely approaching such a calculation: in fact, no one can even perform such a calculation even if we (artificially) limit the calculation to "How will your proposed action impact your (family / neighborhood / city / etc.)?"

So what utilitarianism in practice amounts to is:

• "I want to do X."
• "I can figure out a somewhat plausible subset of the people affected by X who I can imagine would benefit by my doing X."
• "Therefore I will do X."

Thus, a Marxist can justify bombing a factory by the proper utilitarian "calculations" that include the factors that redound to his benefit, while leaving out factors that don't, while the capitalist can just as easily justify running the factory by a similar sort of "calculation."

Conclusion: while utilitarianism purports to be more "rational" than traditional ethical systems, in fact, it is simply a tool for justifying doing whatever it was you wanted to do in the first place, while covering your naked interest with a "rational" veneer.