Objective morality exist, Top Down (God) vs Bottoms Up (Natural)

Thank you, Con.Prior to presenting my rebuttals, I would like to clarify one point. My opponent seems to be under the impression that I am saying that the Christian God is necessary as a basis for morality. I am actually arguing that theism in general is necessary, not Christianity in particular.IntroductionMost have at least heard of Jack London's classic novels White Fang and Call of the Wild. But very few are familiar with his brilliant work The Sea Wolf. The book has essentially no plot, as London wants us to focus entirely on the character of Wolf Larsen. London created in him a literary manifestation of his own naturalist philosophy. At one of the most exciting parts of the narrative, Larsen asks another character why he became nervous when their shipmate was in peril."Do you know the only value life has is what life puts upon itself? And it is of course overestimated, for it is of necessity prejudiced in its own favor. Take that man I had aloft. He held on as if he were a precious thing, a treasure beyond diamonds or rubies. To you? No. To me? Not at all. To himself? Yes. But I do not accept his estimate. He sadly overrates himself. There is plenty more life demanding to be born. Had he fallen and dripped his brains upon the deck like honey from the comb, there would have been no loss to the world."[1]It is in this paragraph that London presents the crux of the problem with the attempts of the atheist to have an objective moral code: it is merely wishful thinking. Throughout the novel, Larsen refers to a character who is also a naturalist but believes in right and wrong as "the sentimentalist."[2] This is language strangely similar to that of Francis Schaeffer. Schaeffer, one of the most esteemed and beloved philosophers of the twentieth century, writes that "Before these dates everyone would have been working on much the same presuppositions [objective moral truth]. [...] Now it may be argued that the non-Christian had no right to act on the presuppositions they acted on. This is true. They were being romantic in accepting optimistic answers without a sufficient base."[3]During this debate round, I will be showing why London and Schaeffer held philosophically consistent views of naturalism while my opponent's is flawed.Rebuttal #1 - Biology cannot be a standard for moralityAlthough I believe that my next rebuttal will make this point irrelevant, I thought that it might be good to briefly respond to this assertion.The human body did not evolve through natural selection of the most moral but the most adaptable. Using it as a litmus test for morality, and mixing philosophy with science in general, is something we must therefore be cautious about. This is especially true when we consider that our psychology can predispose us to do many things which are usually regarded as moral evils. Kleptomania, compulsive lying, psychopathy, sociopathy... the list continues.[4][5] Directly contrary to you point on the body's aversion to harm is the fact that many are genetically predisposed to risk-taking.[6]It might also be worth considering the philosophical position that harm and death add meaning to human existence, but that falls outside the scope of this debate. One may also consider that many find solace or sexual excitement through pain, and so to say that it is objectively bad is questionable. Once again, I believe that will be an unnecessary point to make in this debate.The sum and most important aspect of this rebuttal is that physiology is not necessarily a good working basis for ethical reasoning.Rebuttal #2 - Con has not distanced himself from opinionCon's claims that harm negates the need for a moral authority are the result of not following his argument to its logical end. In actual conversation, his position results in an infinite regress.To argue your position on the basis that life or non-harm are preferable to the individual is to make the presupposition that the individual's preferences must be valued. To call once again upon London's creative mind, let us consider Wolf Larsen's response to your position. It would most likely be a simple "why?" and this is entirely justified. "It doesn't matter what your opinion on killing is. Harm is bad. Killing is harm. Killing is bad.""Impossible, not so fast. I can say theft is morally wrong because theft is a form of harm to the victim."Both of these statements are heavily grounded in the opinion that the preferences of human beings are to be valued and that life is to be considered important. As we saw when I quoted him earlier, Wolf Larsen would consider such assumptions laughable. And, indeed, he is correct if there is no God. With no ultimate moral authority, it cannot be said that Wolf's opinion on the value of life is any less valid than yours. When you had replied that human life is to be valued because you hold to X value, Wolf would simply question why X deserves to be valued.In order to continue this line of thought, my opponent must prove that human life has objective value within the naturalist framework.Rebuttal #3 - My theologically-motivated value of life does not place me in agreement with youAlthough I would certainly agree with you that life is to be valued, this does not mean that I must agree with you in the sense that you wish me to. Let us remember that what we are debating is whether or not your belief system is internally consistent. I would argue that it is not, and that while my worldview causes me to value life you value life despite your worldview.To use Schaeffer's words when describing non-theists who operate on a basis of antithesis, you are "romantically operating on this basis without a sufficient cause, an adequate base, for doing so."[7]Sources1. The Sea Wolf by Jack London 2. Ibid.3. The God Who Is There by Francis Schaeffer 4. http://bjp.rcpsych.org...5. http://www.manipulative-people.com...6. http://genetics.thetech.org...7. Schaeffer, Ibid.