There are two kinds of people in this world:
People who like Star Trek IV: The Voyage Home, and people who don’t.

Sure, but you can create a binary proposition like that for anything. There are two kinds of people in this world:
People who had a bagel today, and people who didn’t.

I don’t think that’s true exactly. For example “There are two kinds of people in this world: People who like the Beach Boys, and people who don’t.” Well, what about people who only like Kokomo, but hate all of Pet Sounds? I wouldn’t say they like the Beach Boys, but it’s inaccurate to say they don’t like them at all.

I guess that’s true. People certainly do have a tendency to reduce every situation to two opposing propositions.

I blame Zoroastrians.

Really? What does an ancient Persian religion have to do with modern thought processes?

Well, if you look at ancient belief systems, they usually had a pantheon. Rather than any one god being a direct opposite of another, they simply represented individual aspects of life and the world. It was the Zoroastrians who first introduced the notion of opposing forces of light and darkness. This dualism was then picked up by Gnostics to a certain degree, and heavily influenced pre-roman empire Jews.

But Jews don’t subscribe to a belief system with an evil equivalent to God, they treat sinfulness and human suffering as an aspect of the physical world and its distance from the Holiness of the Lord.

Sure, they do NOW, but for a period of time around 400 B.C to 300 A.D. it was very common to see the Devil portrayed, if not as God’s equal, as a kind of dark shadow. And of course, while Judaism has returned to it’s roots, relegating Satan to his original role as a warning about what happens to those who cross Yahweh, the Saved Jews, or Christians, held on to this notion, eventually giving him dominion over hell. He went from an inmate to the warden.

Ok, but isn’t the duality really more the result of Manichaeism? After all, Saint Augustine had been a Manichean before he converted, and his role in modern Christian thought is enormous.

I can’t discount that, but I’d argue that
A: Manichaeism wouldn’t have existed without Zoroastrianism, so I’m still right.
B: Zoroastian influence had paved the way for Saint Augustine.

So what you’re saying is, the modern system of analysis where-in each issue must have two opposing sides is because of an ancient Persian cult? Doesn’t this ignore an innate preference for symmetry in homo sapiens? I mean, it’s there in almost everything we create. It’s even in our biology, with our two hands and two eyes to our dual reproductive organs and the hemispheres of our brains.

I feel that ascribing biological pre-disposition to a way of thought is either lazy or dangerous, depending on the argument in which it’s being used. If we’re predisposed to that mode of discourse, why did it take so long to develop?

So what alternatives do you propose, if not a finite system of right and wrong. Would you prefer total ambiguity?

What exactly do you mean by that?

You know, a Nihilist or Experiential approach where morality is seen as completely relative and only defined by the individual’s beliefs and situation.

See, once again, you’ve gone for absolutes. If it’s not binary, it must be all encompassing. There is a very reasonable middle ground in Pluralism. While there can be a variety of cases where-in something is “true”, there are also any number of absolute “false” situations.

Give me an example.

Well, lets look at homicide. One person can believe that killing another person is always wrong. Another can believe that killing a person in defense of his own life is acceptable. Both of these beliefs can simultaneously be “true.” However, if a third person believes that it is acceptable to kill at random for his or her own amusement, this is morally “false.”

How does one determine a moral absolute?

There are probably a few ways, such as taking a few basic principals and assuring that all actions extend from them logically. I’m a fan of Kant’s method personally.

Ah, the “Categorical Imperative.”

Basically. The quick version is “consider your action as if behavior of that type were to become law.” That is, take an action, and think, “If everyone did this/behaved this way, what would happen?” If the broad impact to the world at large is positive or benign, it is morally tenable. If the action or behavior would cause harm, it is immoral.