If I'd studied philosophy, I'd be able to give you a detailed answer to that question; but you wouldn't really be interested in reading it. The history of philosophy is useful only in exposing the stupidities of past thought.
I can give you some idea. Brace yourself. Hegel came up with the idea of the dialectic. He figured that anything that was real was self-consistent and rational. Human intelligence could discover the real by contrasting a statement (thesis) with its opposite (antithesis) and so arrive at the synthesis. This synthesis would contain all that good rational and self-consistent stuff.
A dialectic, then, is like a dialogue or formal debate. With this view of truth, it is not surprising that Hegel believed in the inevitability of war and class systems. This system has more in common with the oriental idea of yin and yang in a monad than with human experience. With trillions of people on the Earth, there have to be more than two points of view.
The technique of limiting discussion to two points of view can be a powerful tool for destroying dissent, particularly in the political arena. If we consider the town hall meeting in Columbus, Ohio, Wednesday, we see opinion before it has been squeezed into the dialectical box. The administration proposed limited, unspecified attacks on Iraq to lessen Saddam Hussein's offensive capabilities.
Leftists chanted against a "racist war." Some people were genuinely concerned about the lives of innocent Iraqis, by which they meant noncombatants. (Why does a man lose his innocence when he's drafted into an army?) Other people thought the idea of limiting the attacks was foolish. What would the repercussions be? Wouldn't the problem of Saddam's bellicosity be magnified? Who could predict the exact results?
In contrast, the debate on the Vietnam War was a neat formal debate and has remained so to this day. It has the nice clean "either-or" character of a dialectic. I've heard people propose that we attack Iraq's oil fields rather than its hard-to-find, easy-to-rebuild chemical and biological weapons manufacturers. Certainly, there were many such options available in Vietnam. President Johnson, however, was able to dialecticalize the debate into Johnson policies vs. peacenik policies.
It was the perfect example of the dialectic or binary fallacy (I just made that up and wonder if it's a real fallacy). By declaring himself the "hawk," he was able to silence the hawks who called for victory over North Vietnam. He also effectively limited the strategic debate. No other method of fighting the war was given a turn at the podium. People are all too willing to accept this either-or form of thinking.
Our two-party system encourages this limitation on ideas. Each party takes a side and parrots the prefabricated arguments of its think tanks while our mainstream press thrives by standing outside politicians' offices and waiting for handouts and declaring itself the bastion of free speech. Stepping outside the bars of the dialectic cage exposes one to the charge of being a radical. Staying inside is a guarantee of emotional support and funding.
In 1996, Congress proposed a 3% growth in the size of government. The president proposed a 5% growth. No other voices were heard in the national debate. Ironically, this dialectic sleight of hand is not used against us libertarians or other real radicals like the communists or greens. The press simply doesn't take the time to cover such ideas. In recent recent years it has been used to marginalize the hard right and "super" patriot positions.
The real hawks were left out of the Vietnam debate, for instance. And consider the case of Timothy McVeigh. Television commentators constantly praised the wonderful job that government prosecuters were doing against McVeigh. The opposition that they chose to debate were people who thought that McVeigh was being railroaded. Who was left out of the debate? There was certainly a case to be made that the government prosecutors were doing a terrible job because they had to cut a deal with the Fortiers, who were probably as guilty of the crime as McVeigh's friend Nichols.
Television commentators set up a parallel debate over Waco: overzealous FBI vs. lunatic cult leader. How about this position: The FBI spent 50 to 100 million dollars to prevent another Jonestown and failed miserably. An immediate frontal assault on the compound would probably have saved dozens of lives, particularly those of women and children.
If there are always two sides to every story, at least one of them is a lie. However, if there are more than two people involved, there are more than two sides. The left and right perceive reality as points on a line. Reality is closer to a four-dimensional hyperduodecahedron.