Here's a topic that is probably long over due.
Not too long ago I came across a person who told me that what was true for me was not true for him, and what's true for him may not be true for me. This would not be a big deal, if we were talking about the best burrito in the fast-food industry. But we weren't; we were discussing reality. Specifically, religion and beliefs.
Let me start by defining truth. Truth is a notion or idea that accurately describes reality as it is.
There are two categories that truth falls under. First, you have "relative truth". "Relative truth" is a truth like what my friend was promoting. A relative truth is one that can conflict with another, yet not cause any issues. These tend to be matters of opinion, perspective, and taste- such as one's preference for Taco Bell over KFC, while someone else can hold it the other way around. Have you ever heard someone say "Its freezing in here!", while the person standing right next to them says, "Are you nuts?! Its burning up in here!" The temperature (freezing or burning) of the room is a relative truth.
Second, you have "objective truth". This is a truth that is true whether someone believes it or not, proves it or not, or observes it or not. 1+1=2 would be an example of one of these truths. Two opposing claims in the same context cannot be both objectively true. Only one can be true. Now, many can be false (1+1=3; 1+1=4.2; etc...), but only one can be true.
Many people like to deny the existence of the second type of truth because by definition, it is quite intolerant of false notions (and labels them quite noticeably) and is exclusivistic. "Exclusivistic" means that it alone is true, and no other opposing claim (in the same context) can be true. It seems to me that in today's global society we want so badly to "get along" that we are willing to compromise the very notion of truth itself to accomplish it.
Unfortunately, for these people, the Law of Noncontradiction stands in the way. This law states that no two opposing claims can be true simultaneously in the same context. Anytime that someone attempts to escape this law, they affirm it. The way an escape is attempted is to simply say that it is incorrect- one does not need to try to justify it because it has already failed. The way the attempt at an escape has failed is that the person making the claim- that the law is incorrect- is saying that the opposite (contradiction) is not correct in the same context. The Law of Noncontradiction is an example of an inescapable objective truth.
This is why I always urge people to do their best to make sure that when they debate someone, they understand the other's position. If the two of you are debating an objective truth, but don't define a few things (establishing the context), then you could be debating when realizing that the fact that you are referring to different contexts is the solution to the problem. Part of establishing context is to avoid a strawman argument (I discussed this in my post "Misengaged in Battle") and defining your terms (I'll go more in depth on this one later in a series of posts).
Objective truths are debated all the time in philosophy and theology. The most popular example is if there is a God or not. Another (less popular, but related) is if objective morals exist or not. Here's one that gets the emotional juices going- are all religions true or not?- or in another way- do all religions eventually lead to God (if He even exists) or not?
The different disciplines of science also search for objective truths. However, different from philosophy and theology, science focuses on the objective truths of nature. Please see my post "Consistency Among Disciplines" for more.
All of these truths (either from philosophy or science) are either true for everybody or they are false for everybody, regardless of anybody's opinion, perspective, or taste.
I have found that in a debate, it is crucial to establish if agreement exists between the parties as to whether or not the topic being debated is a "relative truth" or an "objective truth". If a topic is actually a "relative truth", then there really is no sense in debating (neither side will be held responsible for disagreeing with the other). If it is an "objective truth" then whoever is wrong (not, necessarily, who "wins" the debate) must recognize that the he will be subjected to the implications of disagreeing with the true side of the debate.
Ravi Zacharias gave a talk called The Basis for Truth. This talk was recently provided on Just Thinking. Here are the episodes:
Stuart McAlister from Ravi Zacharias International Ministries discusses truth on this episode of the podcast Just Thinking.
The Gospel in a Pluralistic Society- Part 2
Randall Niles recently posted a video on YouTube discussing the pursuit of truth. Here it is: