An excerpt from a Book I am writing.

1. THE MORAL ARGUMENT

“What seems to us good may therefore not be good in His eyes, and what seems to us evil may not be evil. On the other hand, if God’s moral judgement differs from ours so that our “black” may be His “white”, we can mean nothing by calling Him good; for to say “God is good,” while asserting that His goodness is wholly other than ours, is really only to say “God is we know not what”. And an utterly unknown quality in God cannot give us moral grounds for loving or obeying Him. If He is not (in our sense) “good” we shall obey, if at all, only through fear — and should be equally ready to obey an omnipotent Fiend. The doctrine of Total Depravity — when the consequence is drawn that, since we are totally depraved, our idea of good is worth simply nothing — may thus turn Christianity into a form of devil-worship”
-C.S. Lewis

In my mind the moral argument was, and still is the most convincing argument for the existence of God that I have encountered. This argument was the first in my arsenal in the days when I had fervently applied my time to studying apologetics, consequently, it was the last to fall when deconstructing and analyzing the validity of my beliefs. Some of the major tenants of this argument were promoted by famed German philosopher Immanuel Kant. Kant framed the argument by postulating that moral thought requires the assumption of Gods existence, rather than trying to prove God’s existence outright (ref). However, many modern apologists do in fact use the argument to try to prove God’s existence (Dr. William Lane Craig would be one of the most notable). A syllogistic form of the argument would go as follows:

1. A human experience of morality is observed.
2. God is the best or only explanation for this moral experience.
3. Therefore, God exists.

This is one form, a more common form which relies on the existence of objective moral truths would go as follows:

1. If God does not exist, then objective moral values and duties do not exist
2. Objective moral Values and Duties do exist
3. Therefore God exists

As with all syllogisms, for the conclusion to be falsified, one of the premises must be shown to be fallacious. I will attempt to demonstrate why I think that the premises of these arguments do not hold, and then further elaborate on some of the issues I see with the argument from morality. Of course, I’m under no illusion that I will cover the entirety of the argument, as these points have been developed over thousands of years and by brighter minds than my own (I don’t know if many of us have the time or mental fortitude to plumb the depths of moral philosophy), however I’m simply trying to convey why I personally find the argument to be unconvincing.
A human experience of morality is observed.
I have no issue with this premise, this is verifiable in most cases of human beings.
God is the best or only explanation for moral experience.
Here we must define our terms, what is meant by moral experience? I would assume what is meant is the inward compulsion to do or not do things based on a perception of right and wrong. Of course, we cannot directly observe the moral experience of other humans, we can observe our own inner workings, as CS Lewis put it “The only packet I am allowed to open is Man… especially when I open that particular man called Myself”. So, what we are left with apart from our own inner workings is observing other humans and animals and making suppositions based on our own experience. What we can observe is moral or immoral action. Surprisingly moral action does not seem to be relegated strictly to humanity, in fact we seem to see an increase in moral agency/awareness in animals as we see an increase in brain capacity (ref). It follows then that the alternative explanation for moral experience and action might find its answer in biology rather than metaphysics. But before elaborating on the possible biological origins of morality, we must address the part of the argument which assumes that morality is above and beyond us, while internal, it still feels like an external influence. Why is it that we can know what the right thing is, yet apparently choose not to do it? If we were mere biological engines, and morality is a product of biology, then why would we not follow the “moral law” as everything in the universe follows natural law? Wouldn’t moral law be the same as instinct? At this point I realize I’m in a bit over my head but let me do my best in trying to sort out my thoughts on the matter. It seems to me that morality is inherently social (one can argue that idolatry and other forms of “sin” are not, but I’m trying to stick to what is universally agreed upon as moral). And it is conceivable that morality exerts pressure on the individual due to the relationship to the group, and it is possible that self-interest/preservation can be in tension with the well being of the group. So, I would consider the possibility that if the benefit of pursuing an individual’s self-interest is perceived to exceed the potential retribution from the group, that is when the moral code tends to be broken. The key word here is perception, one individual may see the benefit of stealing a candy bar from a drug store as viable while another may not. One individual may overestimate the benefits, and underestimate the consequences, and the other could be adequality evaluating the benefits, while properly estimating the consequences. This could be done consciously or subconsciously. (The idea of retribution is as old as humans have been around, and it seems to be a key element of religion. This leads me to suspect that retribution in religion is derivative of human nature and group dynamics rather than a product of divine revelation). That is just an idea off the cuff of course and in no way settles the issue. Well then, what about the converse? How about when an individual acts against their self-interest, or even sacrifices their own life for the sake of the group or another individual? How could that possibly fit? Now I think we can briefly touch on the possible biological roots of morality.
Biological altruism is the concept or observation that actions taken by individual organisms can decrease the reproductive fitness of the individual while benefiting the group. This phenomenon is not unique to humanity. One example would be the Vervet monkey, which at considerable risk to itself, will issue an alarm call to the group when a predator is nearby. The monkey runs the risk of alerting the predator to its own presence, so why doesn’t it just slink off? Maybe even allow the predator to take out some of its reproductive rivals? One of the most important concepts in natural selection or evolution that I simply did not grasp when I was a young earth creationist was the concept that species evolve and are selected for in groups. So, say we have a group of selfish monkeys which do not alarm when predators are nearby, and we have a group of “altruistic” monkeys which do. Which group will ultimately be naturally selected to survive? I would argue the group with the higher number of altruists. The Stanford Encyclopedia of Philosophy states this concept most succinctly:
“The problem of altruism is intimately connected with questions about the level at which natural selection acts. If selection acts exclusively at the individual level, favoring some individual organisms over others, then it seems that altruism cannot evolve, for behaving altruistically is disadvantageous for the individual organism itself, by definition. However, it is possible that altruism may be advantageous at the group level. A group containing lots of altruists, each ready to subordinate their own selfish interests for the greater good of the group, may well have a survival advantage over a group composed mainly or exclusively of selfish organisms. A process of between-group selection may thus allow the altruistic behavior to evolve. Within each group, altruists will be at a selective disadvantage relative to their selfish colleagues, but the fitness of the group as a whole will be enhanced by the presence of altruists. Groups composed only or mainly of selfish organisms go extinct, leaving behind groups containing altruists.”(ref)
This one example of alarming monkeys only scratches the surface of similar phenomena found in the animal kingdom. I believe this concept can be extended to explain most if not all of human altruistic behavior; seeing as how we are social animals same as the animal species in which biological altruism is observed. I am certain entire books could be written and have been written on the concept (I would recommend The Altruistic Brain, by Dr. Donald Pfaff, and Cooperation among Animals: An Evolutionary Perspective by Lee Alan Dugatkin), but I believe its simple introduction in the context of this book is enough to make my point. It’s possible that this idea could be a better explanation than what I provided earlier of why there might be a compulsion not to act against the group (as opposed to the idea of social pressure competing with selfish ambition) Needless to say the existence of different naturalistic explanations for human behavior and morality, while most certainly imperfect, makes me less convinced that a Deity is needed or is even the best explanation. More likely it seems that Divine agency was inserted into a narrative or that the ideas of religion were created to explain something that was not understood. Thunder and lighting were in ancient times explained as acts or evidence of God, why not the existence of moral experience? Therefore, It seems to me that to say that God is the only explanation for moral experience is demonstrably false, and to say it is the best explanation is debatable at best.
If God does not exist, then objective moral values and duties do not exist.
This premise is a non sequiter, it in no way follows that objective moral values require a God as. Once again, we must first define what is meant by objective moral values. My understanding of the argument is not that one thing is right to do all the time but rather that in any given situation, there is a correct response and an incorrect response, or several correct responses and several incorrect responses. For example, killing another human being is widely regarded as wrong, Christians will acknowledge that the ten commandments forbid murder, but at the same time, we almost universally acknowledge that killing in self-defense is right. This is an example of where a given action is not by necessity evil in and of itself, but rather the context is what determines its goodness or badness. So in an attempt not to misrepresent the position, this is the definition that I will be using when I refer to Objective morality, as this is (I believe) the intended meaning of Theists. Again, to restate the definition: Objective morality is the idea that in any given situation there are one or more objectively right and wrong actions. The premise leads us to the question: has it been demonstrated that God can be the only possible cause of objective moral values? I am also lead to a second question: if something is objectively right or wrong, how would one know it to be so, how could that be demonstrated? Most theists who hold to this premise, in one form or another will affirm some form of what is called Divine Command theory. What this theory asserts is that objective morality is defined as moral values, principals and duties that are declared by God. This goes one step further from the definition that I set forth earlier, in that it describes a reference point, morality is objective because the declarations of God are absolute (and presumably unchanged) and knowable. But the addition, or the implication of divine command theory in the premise causes an issue. The argument right from the get go is committing a question begging fallacy. The claim is included in the first premise. If objective moral values are those which are declared by God by definition, then of course one can claim that if the existence of God goes, then objective morality goes with it, because God is tied into the definition of objective morality. The issues compound when we dig deeper into morality by divine fiat. Just because someone commands something to be good or right does not necessarily make it so, it is not demonstrably true that we are under the obligation to follow anyone’s command. Furthermore, to say that God only commands that which is good does not solve the issue. This presupposes that we already know good from evil, hence we don’t need God to tell us what to do if we can already tell on our own. It is also possible to imagine a God whose morality is completely opposite of ours, our obedience to the morality set forth by this being would then be purely out of fear, us calling him “good” would mean absolutely nothing from our frame of reference. Ultimately the argument from divine decree would be simply an argument of “might makes right”. Apologist William Lane Craig attempts to clear up this dilemma:
“For those that aren't familiar with it, the question is: does God will something because it is good, or is something good because God wills it? If the theist says that God wills something because it is good then the good is independent of God and, in fact then, moral values are not based in God. They are independent of him. On the other hand, if you say something is good because God wills it then that would seem to make what is good and evil arbitrary. God could have willed that hatred is good; then we would be morally obligated to hate one another, which seems crazy. Some moral values seem to be necessary, and therefore there would be no possible world in which hatred is good. So the claim is that this shows that morality cannot be based in God.
I think it is clearly a false dilemma because the alternatives are not of the form “A or not-A” which would be an inescapable dilemma. The alternatives are like “A or B.” In that case you can always add a third one, C, and escape the horns of the dilemma. I think in this case there is a third alternative which is to say that God wills something because he is good. That is to say, God himself is the paradigm of goodness, and his will reflects his character. God is by nature loving, kind, fair, impartial, generous, and so forth. Therefore, he could not have willed that, for example, hatred be good. That would be to contradict his very own nature.”
For me, this diversion from the dilemma does not solve the issue. To say that God is the “paradigm of goodness” is just saying that God is good by definition. It is saying that the decrees of God reflect his character, if you assume a priori that God is good, then it follows that ...