Peace Depends on Truth

Truth can be a matter of life and death.
That’s no surprise, since it’s happened many times in history. But I want to make a much more difficult argument:
A theory of truth can get people killed.
Huh? What’s a theory of truth? And how could it possibly get anyone killed?
Theories of truth are part of philosophy. Everyone has a philosophy. If you don’t consciously choose your philosophical ideas, you’ll unconsciously absorb the ideas from your environment. In many cases, those ideas will be wrong. Sometimes, they’ll be harmful.
What is truth?
A theory of truth tries to answer two questions:
* What does it mean for beliefs to be true?
* How do we know that beliefs are true?
 The common-sense answer is called the correspondence theory of truth. It says that if a belief is true, then it “corresponds” somehow with a non-mental fact. According to Maimonides, who held the correspondence theory, truth means:

“That what has been represented is outside the mind just as it has been represented in the mind.” [1]
Here’s the cartoon version of the theory. It’s accurate enough for our purposes. Suppose you believe there is a Coca-Cola bottle on the table in the next room. You walk into the room and you see the fact: a Coca-Cola bottle is on the table. Your belief was true because a fact corresponded to your belief. The fact exists independently of you or anyone else perceiving it. Therefore, if your belief is true, it implies that there must be a Coca-Cola bottle on the table. That’s the fact. 
That’s the fact, Jack
But let’s take another look at that fact. The first thing to notice is that it can be true or false. When you perceive a Coca-Cola bottle on the table, you might be mistaken. It might be a bottle of Pepsi or even a small lamp. What verifies your explicit belief (“A Coca-Cola bottle is on the table”) is an implicit belief (your perception of what you see as a Coca-Cola bottle). No matter how much you examine the object, you’re still basing beliefs on your own perceptual judgments -- in other words, on beliefs in your mind rather than what is or isn’t on the table.
Moreover, to recognize a Coca-Cola bottle on a table as a Coca-Cola bottle on a table requires you to know what bottles, Coca-Cola, and tables are. It requires the ability to classify bottles as a type of container, Coca-Cola as a type of carbonated beverage offered for sale, and tables as a type of furniture used by humans for specific purposes. It requires cultural knowledge of soft drinks and commercial products. Depending on who sees it, it might also include knowledge of how glass is made, or a list of the chemical ingredients of Coca-Cola. [2]
How much of that is sitting on the table? Hardly any of it:

“These and many other notions are so bound up with the identification that our thought would lose its character with the removal of any one of them … And these essential elements are not given in sense at all. They are elements in a system, and a system of no little complexity.” [3]
Most of the so-called “fact” is in the mind of the perceiver. And that’s where we get into trouble.
Most people unconsciously think of truth as correspondence because it seems like common sense. And the same people have beliefs, some good and some bad, about all kinds of situations. The idea that their beliefs correspond to facts independent of their own interpretation means that anyone who disagrees with them must be wrong. It can’t be just a difference in viewpoint. If the belief is about something important, it’s a short jump from “wrong” to “evil,” and thence to violence. 
Facts are mostly mental
Let me introduce you to the San people, an African tribe depicted in the 1980 film, “The Gods Must Be Crazy.”
The San live in the Kalahari desert and have had no contact with modern civilization. One day, a plane passing overhead drops a Coca-Cola bottle that lands intact on a soft area of ground. The San have never seen a glass bottle and they consider it a gift from the gods. They think it might be a musical instrument or a tool for craft work. Later, a Western biologist sees it and recognizes it as a Coca-Cola bottle: a manufactured glass container that normally contains a sugary beverage.
The San neither believe what the biologist thinks nor would they understand it. They have never seen factories or manufactured items. They’ve never before seen glass. They have never tasted Coca-Cola or seen any bottled beverage. They know the object fell from the sky and has unusual properties. They consider it a religious artifact. Are they wrong, or do their different beliefs simply result from their different concepts and experiences?
Disagreements about bottles on tables are trivial. But now apply the principle to something of greater consequence, such as the nature of God, the meaning of the Bible, or who has a rightful claim to the Temple Mount. Suddenly it’s no longer just a trivial disagreement. At best, there will probably be bitterness and hatred. At worst, people will get killed.
The correspondence theory of truth is not only incorrect, but harmful. What’s the alternative?
Truth is coherence
The alternative is the coherence theory of truth, which says that beliefs are true if they fit logically with a system of other beliefs. “Fit” means that:

* The belief logically implies some other beliefs of the system and, in turn, is logically implied by them.
* It uses some of the same concepts in the same ways as other beliefs in the system. 
Now, that’s a little counter-intuitive. It means there are degrees of truth. A belief that fits into a large system and has many logical connections to other beliefs is more true than a belief with a smaller system or fewer connections. It’s also more certain because the surrounding system provides lots of evidence for it. Spinoza didn’t quite advocate the coherence theory, but he came close, and he recognized degrees of truth. [4]
Because the coherence theory implies there are degrees of truth, it recognizes the existence of both objective reality and absolute truth.
Everything we perceive and believe is interpreted by our belief systems and conceptual schemes. There is an objective reality, but we can’t get to it. For us, “objective reality” means reality that can be confirmed by other people. [5]
Beliefs are absolutely true if supported by an infinite system of other consistent beliefs, but we are finite so we never have access to an infinite system. All of our beliefs are relative to our own, finite systems of belief. Only God knows absolute truth because only God can comprehend the infinite:

“In all likelihood, there will never be a proposition of which we can say, ‘This that I am asserting, with precisely the meaning I now attach to it, is absolutely true’ … The road of history is so thick with discarded certainties as to suggest that any theory which distributes absolute guarantees is touched with charlatanism.” [6]
Logically, it means that apparently inconsistent beliefs can all be true, each relative to its own supporting system. The beliefs are about different things so they don’t really conflict. The San people believe a Coca-Cola bottle is a religious artifact because that’s how it fits into their system. We believe the religious artifact is a Coca-Cola bottle because that’s how it fits into our system.
Coherence and social peace
By itself, understanding the nature of truth won’t bring social peace. Human beings will still be human beings. Conscience and intelligence will still battle Yetzer Hara and the biological nature we share with lower animals. Terrorists still won’t think about their philosophy before trying to murder innocents.
However, if our understanding helps us support greater tolerance of differing viewpoints and ways of life, we can improve things a little. That’s the truth.

Works Cited
Blanshard, B. (1938), The Nature of Thought, Volume 2. London: George Allen & Unwin.
Pines, S., translator (1961), Moses Maimonides: The Guide of the Perplexed, Volume 1. Chicago: University of Chicago Press.
Shirley, S., translator (2011), Baruch Spinoza: Ethics. Indianapolis: Hackett Publishing Co.
Footnotes
1. Pines, S. (1961), p. 111.
2. For a high school chemistry project, I analyzed Coca-Cola. The company was kind enough to provide me with a case of Coca-Cola for testing. They said that they weren’t worried because part of their secret was the order in which the ingredients were mixed.
3. Blanshard, B. (1938), p. 229.
4. Shirley, S. (2011), p.32ff. Spinoza thought that our understanding of things was proportional to how much we knew about their causes. A belief based on more knowledge of causes is more true than a belief based on less knowledge.
5. Of course, our perception of other people is also interpreted by our beliefs and conceptual schemes, but we just have to take them on faith. We have to start somewhere. Solipsism is logically irrefutable but completely useless. 
6. Blanshard, B. (1938), p. 270.