Is utilitarianism a logical fallacy?

[Alcon]

Yes.

One could use utilitarianism to justify rape, among other things.

You do realize, that by arguing that a system is fallacious, because it would allow for something "bad" that is not considered "bad" under that system, you're committing a logical fallacy yourself?  And you're entirely misappropriating the term "logical fallacy," as well.

[Alcon]

He's really just making the badness of rape an unstated premise. If you grant him that premise, as well as his explicit one, then the only thing wrong with his conclusion is the use of "logical fallacy" in place of "fallacious."

Of course, that's not to say that anyone who accepts the premises would, when presented with the argument, have to accept the conclusion. Instead, he might rethink his support for the premises.

But arguing against something on the basis of a premise the other party doesn't concede, and is entirely opposed to their thesis is...retarded.

Not exactly a logical operative term , but still.  This is one degree removed from "nihilism sucks because it supports apathy."

[Alcon]

He's really just making the badness of rape an unstated premise. If you grant him that premise, as well as his explicit one, then the only thing wrong with his conclusion is the use of "logical fallacy" in place of "fallacious."

Of course, that's not to say that anyone who accepts the premises would, when presented with the argument, have to accept the conclusion. Instead, he might rethink his support for the premises.

But arguing against something on the basis of a premise the other party doesn't concede, and is entirely opposed to their thesis is...retarded.

Not exactly a logical operative term , but still.  This is one degree removed from "nihilism sucks because it supports apathy."

As plausible as what you're saying sounds, its assumption is wrong. It's simply not true that a person who maintains x can't simultaneously hold beliefs that, upon inspection, turn out to flatly contradict x. None of us have ever carefully sat down and thought through all of the implications of the various beliefs we hold; and how any set of them may relate to some other belief.

Let me try this on you. Are geometric proofs a waste of time? And if not, why not? Aren't they equally subject to your critique? (Anyone who ever doubted the Pythagorean theorem must have disagreed with the premises, no?) Indeed, aren't all logical arguments equally subject to it?

Oh, I have no problem with consistency tests.   I was only making fun of BRTD because I (maybe wrongly) assume that wasn't his intention (based on the question "is utilitarianism a logical fallacy?")  I mean, I assume BRTD understands what a logical fallacy is in a general sense, enough to know it's different from a consistency test.  But maybe not.

You'll have to explain your Pythagorean Theorem reference if it's anything other than an explicit analogy.  I got a "B" in geometry four years ago

[Alcon]

An ethical philosophy can be so if one uses fallacious arguments based off it. Is "Moderate Heroism" a logical fallacy? Not exactly, but the basis of it is a commonly accepted fallacy (Middle Ground.)

Positing that moderation is better (for some given set of reasons) is not a logical fallacy; positing that it is inherently better because it is moderation (unless you define "good" using "moderate" for some reason), is a logical fallacy.

It's one of a wide range that basically consist of confusing correlation and causation.  If you were picking an option blindly, the moderate option might generally be best; but abandoning additional information for "moderation" is fallacious, if you can evaluate it on actual merits.

When I was a kid I used utilitarianistic arguments against doing things like cleaning my room. I'm sure those would be considered fallacious.

Why?  There is nothing logically unsound about an ethical system that posits that victims of rape should abandon irrational feelings of violation in favor of utility.  How is that fallacious?

Your argument, as John points out, was not utilitarian anyway; it was narcissistic and hedonistic.  That doesn't make it fallacious either, if you define your world around your own personal pleasure -- or your ethical system around each individual's.

[Alcon]

Here's another example of utilitarianism:

A lapdance costs $20 at most clubs I go to. I find someone carelessly leaving their wallet around at some bar or party. Inside there's a couple hundred dollars. I know they won't miss a single $20 bill, so I steal one and then go get an awesome lapdance.

Utilitarianism says this is a justifiable action.

Yes, so?