Naturalism provides a sound basis for morals

Your argument falls to pieces in your first 5 sentences. By your own admission, objective morality is not possible without an objective moral law-giver (i.e. a creator). Therefore morality in your view must be subjective. Therefore the extant to which any thought, action, or in-action is "good" or "bad" is relative to an individual's opinion. Therefore naturalism does not provide a sound basis for morality, if by "sound" we mean reliable. How can you rely on morality when it is subject to an individual's opinion? In your view, Hitler's morality is no better or no worse than Gandhi's morality. This is because morality is subjective and Hitler may think his actions were "good" and Gandhi may say they were "bad" and vice versa, but there is no objective standard by which to judge these two sets of morality. Therefore morality in your paradigm would have to be irrelevant and unreliable. I really don't have to say anymore, nevertheless I will address the rest of your argument. The rest of your argument is contingent upon the disappointing statement, "Our search for naturalistic explanations finds solace in Darwin"s mechanism of natural selection." This assumes that natural selection is a valid mechanism for which to place one's trust in naturalism. Natural selection only works to select from what is already present in the genome, it does not and cannot add anything new. Unless you cite a mechanism which demonstrably can change a scale into a feather over time, your whole argument is invalid. Let's continue. Your argument of reciprocal altruism is flawed. As you state, "Simply: if you scratch my back, I"ll scratch yours." Reciprocity is the key element to note. Can you really say this phenomena is the animal kingdom is an example of pre-human moral development? The reason a monkey helps another monkey, even if it puts itself at risk, is that it expects other monkeys to do the same for him. This is a far cry from a selfless act of honor, and it in no way supports your main argument. You say, "With this mechanism at hand, it is not hard to see how our morality might have evolved." What mechanism? You cite no mechanism, all you do is state certain phenomena but make no demonstrable link to human morality. And if you think you have, then consider yet another flaw in your argument. You seem to be asserting that morality is rooted in survival, that is, if I do something to help another survive, like preform CPR for instance, I have done something morally "good." But really, there is no reason to say it is morally "good" as I could just as well decided not to help the person for my own reasons which can be just as morally "good." If an animal helps his fellow animal by warning him of danger, it is not morally "good" as the same animal can kill his fellow animal for the same reason: survival. A male lion will often kill cubs in order to coax the female into mating again. This can be seen as good for survival but you cannot say it is immoral. And besides this, whose to say survival of a species is good? Consider this quote by naturalist Jacques Cousteau, "In order to save the planet it would be necessary to kill 350,000 people per day." Is this a moral or immoral statement? Well if morality is determined by survival of a species then sure its moral, but what species should survive? Should humans be preserved? Should animals? Both? It's up to one's opinion. Back to square one of the problem with your argument thus far. Your most confounding statement is when you say, "Perhaps, then, after we have observed a potential explanation for why we have these moral intuitions, we can resolve that naturalism does indeed provide an explanation for morality." Firstly, you seem to imply that, thus far, neither you nor anyone else has resolved the exact position you are arguing for. Therefore you have shot yourself in the foot. Indeed neither you nor anyone else has or can provide such a sound explanation. Secondly, you seem to acknowledge that as human beings, we have moral intuitions. The Bible of course tells us why, humans have God's moral laws "written in their hearts, their conscience also bearing witness..." (Romans 2:15). Only man was made in the image of God (Genesis 1:27). While the Bible provides a sound answer, your naturalist paradigm does not, as even you admit. You're left to study beasts in order to explain why humans know murder is wrong, stealing is wrong, lying is wrong, etc. Is it wrong for a lion to kill an antelope? He has to survive right? Is it wrong for Hitler to kill Jews? They have to survive right (as Hitler taught that Jews carried diseases and the like which would eventually affect all humanity and be the cause of their extinction)? The ultimate flaw in your argument lies in the idea of "good" and "bad." What determines whether a though, action or inaction is "good" or "bad." It is basically the same question of morality, only at a more fundamental level. Why should selfishness be "bad" as you seemed to imply? Why should survival be "good"? Without an objective moral standard, you cannot soundly state that one though, action or inaction is either "good" or "bad." The reason I do my best not to kill, steal, etc. is because I have a moral standard, the Bible, and I know I will face judgment one day. The reason you do not kill, steal, etc. is based entirely on opinion. You may very well kill, steal, etc. and that would be based on your opinion as well. No, you cannot have an objective morality without God, and a subjective morality is not sound. So according to your resolution, I have won. I await your response.