Modernist or Christian apologists tend to use an argument along these lines:
The claim that “all truth is relative” is an absolute, non-relative claim. If it is true, it proves that at least one claim (itself) is not relative, and therefore it is false [self-refutation]. On the other hand, if it is false, then it is false [tautology]. Therefore, no matter what, it must be false.
More generally, the argument is that any argument about epistemology — any bedrock claim about how to prove claims — cannot depend upon any epistemic claim besides itself. For example, if I believe that “everything can be known through the rational intuition of the mind” then I had better justify that statement using the rational intuition of the mind. If, say, I justified that claim using the five senses, then I have undermined myself.
Sure. Fair enough. Makes for a good satire article every now and again. In an eighth grade literature class discussion about Lord of the Flies my teacher made the claim “there is no absolute truth.”
(How we got there from LOTF?)
It could be said that my entire philosophic training up to that point had been aimed at preparing me for exactly this situation. They had trained me to pounce, and my opportunity was now: Ambush philosophy!: “BUT THAT STATEMENT IS AN ABSOLUTE TRUTH CLAIM,” I blurted out. My teacher paused. She had no response. After a beat she said, and six years later I remember the exact quote: “man, Ross, I could listen to you talk all day,” which in retrospect was exactly the worst thing to say to the kind of person who would employ that kind of argument.
But I digress. There are two fatal problems with the argument.
First, the claim “there is no absolute truth” almost never means truth-at-all. The person speaking means that “there is no absolute meta-narrative truth.” They do not claim that we cannot know the specific facts of life. Who would think that? Perhaps Berkeley? Instead, the postmodernist argues that we cannot know how to compile those specific facts into something meaningful.
Go read the essay Amateur Sociology Considered Harmful by Ozy Frantz. I’m not kidding, it demonstrates a postmodern rejection of meta-narratives better than Foucault or Derrida, who created it. (Or, maybe, a less sophisticated rejection?)
A relevant excerpt:
Bright-eyed and bushy-tailed, the young sociology student takes her first theory class. The first week, she reads Smith, who presents a plausible and insightful argument that the invisible hand of the market causes goods to be distributed in the way that best benefits everyone. The second week, she reads Marx, who presents a plausible and insightful argument that capitalism is a product of bourgeoisie ownership of the means of production which alienates the proletariat from their labor. The third week, she reads Durkheim, who presents a plausible and insightful argument that industrialization leads to anomie, a condition in which society provides little moral guidance to individuals. The fourth week, she reads Weber, who presents a plausible and insightful argument that the capitalist spirit originates in a Calvinist urge to find signs whether or not one is a member of the elect. The fifth week, she reads Mills, who presents a plausible and insightful argument that the ordinary citizen is a powerless tool in the hands of corporate, military, and political leaders who control society for their own ends.
At this point, if all goes well, she storms into her professor’s office and says “okay, I can kind of harmonize Smith and Weber, or Marx and Durkheim, but mostly these authors not only don’t agree with each other, they don’t even seem to be describing they same thing! They are at utter disjoint! None of them even agree about what categories we should be using! And yet when I read Weber, he makes sense, and when I read Marx, he makes sense, and when I read Smith, he makes sense! HOW CAN THIS BE? AAAAAAAAAAAAAA!”, and a sociologist is born.
In this sense, the postmodernist is not rejecting specific truth. As you see later on in the article, Ozy does not have any problem with attaining facts, and I’m sure that they hold to the same mindset as a secular humanist, who argues that reason and evidence are the two and only two methods for justifying claims. (Since Ozy is a rationalist, I am sure this is the case).
What, then, is the difference between a secular humanist and postmodernist? They can both assent to the warrant of particular claims, but the latter does not assemble those particular claims into something meaningful. How can we? they ask. The postmodernist engages in a “stark refusal to cultivate a nostalgia for the unattainable” (Putt) while the former seeks to systematize and formalize all truth into what would traditionally be considered a philosophically coherent and confident model.
Second, The other problem is that the claim “there is absolute truth” is itself an absolute truth claim, and therefore commits the converse fallacy, that of circular reasoning. I think that Karl Popper was the first to point this out, though I have since lost the blog link when my other computer died and my bookmarks fared accordingly. Popper formulated it like this:
To prove any epistemic claim, one must
1. Use the claim itself (which is circular reasoning)
2. Use another claim (which undermines the original claim’s purported status as an epistemic foundation)
3. Leave the claim unproved (which does not prove the claim)
That critique does not really have a satisfactory answer, that I have yet seen. I have found so far one good answer, and that involves applying Bayesian rationality, describing all beliefs in terms of a probability between zero and one, testing, feeding the outcome back into the original equation to adjust priors, and repeating until the event incident reaches 0.00 or 1.00.
MAYBE that works. It is a fairly new concept to me, and I’m not sure how we can use that type of reasoning on an extremely abstract, (perhaps unfalsifiable?) level like the foundations of epistemology, or even a few layers up the ladder on issues like the reliability of reason or the degree to which the senses accurately perceive the world. The next thing I am set on uncovering is whether someone can prove than Bayes’s formula is a priori synthetic knowledge on par with 2+2=4, Kant style. Can that be done?
If so, there might be an answer there. But either way, the original objection to the person denying absolute truth is, at best only half the full picture, and at worst a complete misunderstanding of the meaning of the words in use.