Christian author Frank Turek, while not a philosopher in training, engages with issues of epistemology and metaethics. Being an apologist, as well as an evangelical, Turek supports a metaethical theory based on the will of God, as understood in his religious tradition. With co-author Norman L. Geisler, Turek argued for absolute truth in religion and morality in the book I Don't Have Enough Faith to be an Atheist (Weaton, IL: Crossway Books, 2004). While claiming to be a sound response to atheism, skepticism, and secular ethics, Turek misconstrues Absolute truth as a way to defend his Christian theism and metaethical assertions. For brevity, I will respond directly to a summery of points from his book.
One expects the truth from product labels, especially from medicine bottles. Thus, one ought to except truth in religion and morality (36).
People don't demand truth from a medicine bottle, rather, they would like for the label to accurately describe the effects of the medicine. Medicine is a science; its claims can be empirically tested. There are different sorts of truths. For example, Kayaking is exercise is true in a different way than Kayaking is life-changing exercise. One broad way to divide truth is between descriptive and prescriptive truths. In my kayak example, the first claim can be verified through physiology, while the second has a value judgment, and implies that one ought to take up kayaking.
Truth is what corresponds to absolute reality. Thus, truth cannot be subjective (36-37).
This is problematic. Most people, I imagine, assume this is how truth works: there are statements, there is an irrefutable reality (and if there are any questions about reality, if you squint hard enough, you'll get it), and those statements had better map out the hard, objective reality, or else its not the truth. This is the correspondence theory of truth, and I don't buy it.
Problem 1: What is this absolute reality?
If you believe there are objects and forces outside of your sense of perception, that's good and all, that does not demarcate what Absolute Reality is. What about emergent phenomena, that is, properties objects have that cannot be parsed out by examining the parts that make them up? Is money a part of absolute reality? Nothing about the physical makeup of a bill will explain why people will exchange goods for it. Is language a part of absolute reality? Because noting the motions of one's larynx, the characters of an alphabet, or the waves of sound will explain the causal influence words have. What about feelings? Or pain? Orgasms? Qualia, or the subjective phenomenal experience, defies a reductive explanation.
Problem 2: How would we confirm that a statement successfully maps out an absolute reality?
The Montgolfier brothers in the 18th century pioneered aviation with their incarnation of the hot-air balloon. The brothers suspected that smoke contained a gas that allowed the balloon to inflate. This proposition, Gas X, as contained in the smoke from a fire, allows a balloon to float, explained a natural phenomenon, and allowed for the production of a useful technology. While we now know that heat is the causal property, the Montgolfier brothers' proposition mapped out rather well for what they saw as absolute reality. Similarly, things like quarks, black holes, and string theory are not observable or proven beyond their application in the available theory.
Problem 3: Even if the Bible were an inerrant Divine Revelation of an Absolute Reality, we would not be able to read it.
In the novel Good Omens, co-written by Neil Gaiman and Terry Pratchett, the witch Anges Nutter wrote a book of prophesies that are so accurate, nobody understands them until after they happen. Then suppose the Bible were the ultimate source of truth statements that perfectly correspond to absolute reality. How, then, would we make any sense of them? The metaphysical propositions that come out of the Bible, or out of the creeds of the early church, cannot stand on their own, but are reliant on a web of interpretation and tradition in order to make heads or tails.
Truth can be understood in other ways than simply corresponding to a supposed absolute reality. The Coherentist Theory of Truth argues that reductive propositional statements don't lead to a final truth, but rather, that we have a Web of Beliefs (as coined by W.V.O. Quine) that serve us, and that beliefs will need to be modified with new information.
To state There is no truth, or Truth is subjective, is contradictory. Religion truth, then, is objective (37).
Let me address the second claim first. False, there are subjective facts. I am in pain, Mozart's Requiem makes me feel anxious, My finger doubles when I hold it an inch in front of my eyes are all facts, but can only be understood subjectively.
Oddly enough, the greatest Christian philosopher of modernity, Soren Kierkegaard, argued exactly that capital-T Truth is subjective. Questions like, What should I believe? How should I live? or Whom shall I marry? must be answered through recognizing the limitations of one's reason (which is itself rational) and entering through a leap of faith. The most important questions of one's life are bound to be appraised, understood, and responded to through the passions and intuitions of one's subjective experience.
To address the first issue, there's a bit of leap Turek's taking, as he's conflating descriptive truth statements with prescriptive truth statements. Suppose we came to know by an incredibly reliable process that the God of the Old Testament not only exists, but that every word in the Hebrew Bible is historically accurate: God really did curse women into childbearing, God really did stop the rotation of the earth to give Jacob more time to win a battle, God really did kill every life form except for the select few on Noah's Ark, God really did summon a pair of bears to maul a horde of hecklers to death in front of the prophet Elisha. Even if all of that were literally, totally, absolutely, no-questions-about-it true, it still would not follow that the God of Abraham, Isaac, and Jacob is the God worthy of worship.
If truth is objective, then so must knowledge. One who claims they cannot know anything for certain is making a knowledge claim (43).
First, there are things we know for certain: 7+5=12, or the law of identity. Second, if one states that We can't know anything for sure, they are almost certainly talking about empirical issues, matters of fact, not questions about the relationships between ideas, which are, for the most part, necessarily true. The statement I cannot know anything about the empirical world for certain, is a heuristic that is achieved by a priori reasoning, thus the statement is not self-defeating. Second, there is the Gettier problem, named after an obscure philosopher who published one paper that flipped the entire enterprise of Epistemology (the study of knowledge) on its head, and then was never heard of again. Knowledge has usually been generally understood as justified, true belief. However, one can come to believe something that is true, but through flawed methods. Does that still constitute as knowledge, then?
Here's an example: Galileo was convinced that the heliocentric model of the solar system was true. However, his actual attempt at a proof of the rotation of the earth was based on the motion of the tides, unaware how the moon is the salient force for the tides.
While this might sound more scholarly than relevant, consider all the people who consult psychics, Ouija boards, faith healers, or sham economists. In the event that one of these figures happens to confirm one proposition, does that validate their questionable practice, much less validate your broader web of beliefs? How many people are convinced of an entire fundamentalist program, just because they went to a faith healing service and, in the middle of a round of the power of suggestion and group psychology, felt like their back pain had vanished? Or maybe saw an improvement in their lives not from any kind of supernatural influence, but because they finally had a social community to be a part of?
On the contrary, it is absolute, objective knowledge that is the stranger position to take, and is unnecessary in a coherantist or pragmatic theory of epistemology.
If one were a skeptic about everything, then one must be a skeptic about skepticism. Thus, skepticism, as a general disposition, is self-refuting (43).
Turek mistakes Epistemological Falliblism for skepticism. Related to the Gettier problem from above, I can accept that a wide range of my beliefs are justified, but still not true in an objective sense, or may be superseded in time. Still more, an acknowledgment of the fallibility of my beliefs needs not be a propositional statement, which is true or false, but can be a recognition of their incomplete nature.
Actual skepticism is a null hypothesis, thus the act of doubting skepticism is incoherent. One presents evidence or argument to a skeptic to sway them out of a null set. With this perspective, it is fully possible to make moral judgments, as having an absolute, objective ethical standard is not necessary to do the work of being a good person. In fact, we do not have the choice to wait for knowledge of absolute truth in religion, morality, or even medicine. We act with the best knowledge available, and if we are honest with ourselves, hope to modify our beliefs with additional reflection and experience.