So, previously, I talked about some well respected thinkers' assessment of the "is-ought" fallacy (part 1) here.
As Dr. McDurmon reiterated and as Hume and Moore actually believe, when one is entirely consistent with (atheistic) naturalism, all three thinkers are exactly correct in understanding that one cannot derive any notion of an "ought" from an "is." In other words, we cannot logically say that since little Johnny is Timothy's son (is/indicative), and therefore, Johnny must obey his father (ought/imperative). This is further confirm when Moore rightly understood that naturalism "offers no reason at all, far less any valid reason, for any ethical principle whatsoever; and in this it already fails to satisfy the requirement of Ethics."
At this point, it is probably helpful to define what exactly I mean by "naturalism." Generally speaking, we can think of naturalism as subdivided into several different "strains." Metaphysical (philosophical) naturalism from which you can derive moral naturalism, and methodological naturalism (science related).
Methodological naturalism is the label for the required assumption of philosophical naturalism when working with the scientific method. Methodological naturalists limit their scientific research to the study of natural causes, because any attempts to define causal relationships with the supernatural are never fruitful (Rational Wiki). There is a lot to be said about methodological naturalism but I am going to focus more so on metaphysical naturalism in this post, although methodological naturalism does have relevance to this discussion as well.
Metaphysical naturalism (MN) (or "ontological naturalism" / "philosophical naturalism" is a philosophical worldview and belief system that holds that there is nothing but natural elements, principles, and relations of the kind studied by the natural sciences. Metaphysical naturalism holds that all properties related to consciousness and the mind are reducible to, or supervene (dependent) upon, nature. Broadly, the corresponding theological perspective is religious naturalism or spiritual naturalism (Wikipedia).
"Nature" in the sense that MN defines it necessarily excludes anything immaterial (e.g. God, logic etc..). It is crucial to understand how MN defines nature because the Christian view of nature is remarkably different in certain respects. If you ever studied science (chemistry, bio, physics) in college or high school, you will understand that science's inherent function can never study anything beyond the material, or "natural," realm.
So, from a proper understanding of metaphysical naturalism, "nature" (as MN understands it) is purely physical and material, and never immaterial. Within MN, morals, ideas, emotions etc... are logically accounted for by regarding them as merely chemical reactions or physical movements of molecules in our brains etc... With this "naturalistic" understanding of morals, ideas etc... (anything immaterial), if they are simply chemical reactions, or movement of molecules, and if we understand that there is no such thing as an immaterial concept/object, the conclusion will necessarily follow that morals, ideas etc... are ultimately meaningless, arbitrary and are not under a transcendent standard. You can try putting it into a syllogism to test out how the propositional variables will logically lead to my conclusions.
From this understanding and conclusion of MN, we can see how the "is-ought" statement really is a fallacy when looking at it from a purely MN point of view. Johnny obeying his father could simply be seen as a merely pragmatic thing to do (in order to survive etc...). Timothy knows more to keep Johnny safe and secure and to help him grow etc... So, there is some value in Johnny obeying his dad, but it is never regarded as an imperative. It is only regarded as a survival/evolutionary issue. If the immaterial doesn't exist, we have no basis for saying that Johnny must obey his father.
If we look at a garden variety non-Christian, we see that MN is working in his mind and heart. From the Bible, we also see that he does have the natural law that was implanted in his heart from his birth (Rom 2:14-16). Related to MN, we see that the non-Christian is heavily influenced by evolution, and the "scientific" claims that there is no God. If there is no God, MN is necessarily true. So, in the non-Christian, we have three things that are in an inconsistent "harmony" with each other. The evolutionary worldview and from this, MN originates. And the natural law that God has implanted in a man's heart.
It is important to understand that this is the current state of every man who does not know God. And this is crucially important to help understand why the (R)2K doctrine and the way in which Escondido espouses natural law, while beneficial in a limited temporal sense, can never actually be a fully epistemologically sufficient means of arguing ethics.
The (R)2K doctrine emphasizes heavily upon appealing to nature and attempting to convince a non-Christian on the basis of nature for various creational truths (marriage, man, woman, morals etc...). Yes, appealing on the basis of nature is necessary condition (A cannot occur without B). However, what all (R)2K proponents misunderstand is that simply appealing solely upon the basis of nature is NOT a sufficient condition (A guarantees B).
This is why: I mentioned before how the natural man has three things in his heart and mind that are in inconsistent "harmony" with each other. The evolutionary worldview, the MN that flows from it, and the natural law that God gave him. Natural law does say all of these various creational truths, and from the beginning, natural man understands and in fact. ***knows*** these things. However, natural man is also influenced and affected by evolution and MN (and thus sin). Because of this (among other things), he cannot properly understand natural law.
Because of this, there are several problems with the (R)2K understanding of appealing to natural man.
(1) (R)2K's insistence that the non-Christian man can consistently understand nature or at least certain parts of it is true (sometimes). However, (R)2K then overcompensates by then using natural man's proper understanding of nature as the de facto standard for the necessary and sufficient conditions of an argument.
This methodology does not take into account the evolutionary worldview and MN that are at war (or are in inconsistent harmony) with the natural law in his heart. I mentioned how MN's understanding of nature is completely different from a Christian's understanding of nature. The presuppositions are entirely different. MN believes that nature is completely material. The Christian's understanding of nature includes both material and immaterial (natural law).
(R)2K fails to take this issue of entirely different presuppositional understandings of nature into account at all.
(2) (R)2K's insistence that we appeal to what non-Christian man knows or understands "by nature" is of some value (very limited). Because of the natural law in their hearts, there is some intersection of agreement between what we as Christians understand about nature, and what non-Christians can understand about "nature". However, there are some subtle yet very significant problems.
(a) I mentioned before about the issue of necessary conditions and sufficient conditions. It is necessary to bring up nature as a basis (as Christians properly understand it) for morals etc... However the fatal flaw in (R)2K is that they seriously misunderstand in thinking that something being necessary automatically means that it is sufficient.
(b) When you appeal to nature, and to nature ONLY, although your conditions and conclusions about nature are correct, if (R)2K never actually deals with the transcendent basis behind nature (ie: God, the Bible), the arguments placed forth for the Christian position become exactly as arbitrary as the non-Christian's MN position. Therefore, the arguments are not sufficient.
Christian: "I am right about nature and how things should be ordered."
Non-Christian: "Well, I dont accept and don't agree with your statement about nature. What basis do you have to say that I am wrong and you are right?"
Christian: "The natural law"
Non-Christian: "Where does natural law come from? From my MN point of view, natural law is simply a figment of chemical reactions in my brain."
Christian: ......... (since he can't use the Bible to refer to as the ultimate transcendent standard)
To in fact be unwilling to refer back to the Bible and the Triune God as the epistemic warrant for your conditions of natural law, morals etc..., and to simply stand behind your statement that natural law is true (which it is) without proper argument, you are simply asserting it without proof.
When you simply assert something without argument, you are being just as arbitrary as the non-Christian and committing question begging.
(3) Finally, part 2(b) really speaks to a larger issue of evidentialism and presuppositionalism. (R)2K will ardently say that they are being Van Tillian and presuppositionalist. But, simply asserting that you are these things doesn't mean that you actually are.
If we are to understand that we are not ***allowed*** to use the Bible when discussing ethics with a non-Christian, and we are to only appeal to what they already know, I already discussed about how this does not make sense from a presuppositional point of view (part 1).
It is clear from this brief study of MN (and the evolutionary world view) that the non-Christian man absolutely does not have the same presuppositions as the Christian does when looking at nature. He doesnt even define it the same as the Christian!
And yet, we see how (R)2K demands that we appeal to their understanding of the evidence of natural law and what they already ***know***. I mentioned before how this does have limited value because of the natural law in their hearts, and because of that natural law, they do understand certain things.
However, I would never recognize these arguments as sufficient in the way that (R)2K understands it.
(R)2K in fact does recognize these arguments as sufficient.
Think about it. If you insist on only appealing to man's understanding, and the evidence of natural law, and what he knows, this smack's of evidentialism at its methodological and apologetical core. With this understanding, you have never dealt with his presuppositions about what nature exactly is, and what he knows about nature, and how he can come to know exactly what nature is.
The entire basis behind VT and presuppositionalism is in fact the understanding that we don't ultimately argue with the non-Christian on his terms, on "neutral" ground, or on anyone else's basis except the standard of God.
(R)2K will say that they believe the basis is God when they argue for natural law. and I do agree with them that they do. However, their particular methodology belies this point. Even Josh McDowell believes that God is the eternal moral standard. But, how does he argue? He is a strict evidentialist, and argues from that "ultimate" starting point of "evidence."
There are more nuances to this... and I dont want to sound like I am overstating myself. There is value is using natural law arguments, but they have to be done properly.. I will try to show this next time and I will also try to round out the discussion about the "is-ought" fallacy as well.