Thursday, October 13, 2011

Why Plantinga's EAAN Argument is a Non-Sequitur

In Christian theologian Alvin Plantinga's book Warrant and Proper Function, Plantinga argues that, if both:

(N) naturalism – the view that there are no supernatural beings

(E) evolution - current evolutionary doctrine

are true, then the probability that:

(R) our cognitive faculties are reliable and produce mostly true beliefs must be either low or inscrutable.

Plantinga claims that this argument gives anyone who accepts N&E with a undefeatable defeater for any belief produced by those faculties, including N&E itself. Hence, N&E has been shown to be self-defeating (this is his Evolutionary argument against naturalism).

Basically, he is saying that "the combination of evolutionary theory and naturalism is self-defeating on the basis of the claim that if both evolution and naturalism are true, then the probability of having reliable cognitive facilities is low."

Now I am not going to criticize Plantinga's skills of philosophy, but it seems to me he actually hasn't thought about the ramifications of the claim.

If no cognitive judgments can be made, then rationality, is an illusion. We only think we are being rational, but in reality, our ability to make a rational, cognitive, decision would exhibit the same probability as a coin toss.

I offer an extremely easy to do scientific experiment which would show that Plantinga's theory is, in truth, a non-issue. It's basically a non-sequitur, and here's why.

Let's test the theory. We shall use a coin. We will give a control group certain problems to solve, while another group will be given the same problems. These problems will require using the cognitive function of the brain and thinking rationally to solve. While the other group will be attempting to answering the same problems based on random coin tosses.

If we see that the ratio of cognitive based problem solvers happen to provide the correct answer, and solve more problems, more often than the coin tossing based problem solvers then we can safely say cognitive function exists--regardless of whether naturalism and evolution both being true makes the probability of cognitive function low. Indeed, having tested the ration of random coin tosses with the ability to rationalize we would at least know, that having validated cognitive function, that the existence of cognitive function is real despite Plantinga's theory that it would be nearly non-existent. 

So we must test it. Here is my proposal.

Friday, October 7, 2011

Due Criticism: The Appeal to Authority

The appeal to authority may be the most widely relied upon informal fallacy there is. Of course the reason for this is most likely biological and psychological. From infancy we have no choice but to rely on the protection and safety of higher powers. These powers are usually represented by our parents and guardians, elders, leaders, and governments. It is also why many people, once fully actualized adults, still seek authority figures in their lives. Without a King, or President, or a functioning government--most people wouldn't have the structure they need in their lives--a structure which reflects their entire upbringing since the day they were born.

Indeed, society as a whole is largely structured with authority in mind. It is why armies need dictators, militaries rely on governments, the pious rely on the priests, and so on and so forth. It is no wonder then that we innately appeal to authority when we are trying to justify our desires, needs, as well as actions.

What I am concerned with here, however, is a specific form of authority used in academia. It is the argument from authority. Now, the appeal to authority is one means in gaining support to justify an argument, idea, or belief. Basically any position we take must be validated before it can become formally accepted. If you write a book on the history of George Washington, it helps to cite historians, and better yet, historians whose expertise is centered on the time and place of your topic. Another important factor is whether there is a consensus on the relevant information. Do the experts agree?

The thing we must keep in mind, however, is that the appeal to authority should be just one aspect of the support we seek--it should not be the sole piece of evidence we have supporting our position--because even authorities can be mistaken or misunderstood.

Appeal to Authority

The appeal to authority may take several forms. As a statistical syllogism, it will have the following basic structure:
Most of what authority a has to say on subject matter S is correct.
a says p about S.
Therefore, p is correct.
The strength of this argument depends upon two factors:
  1. The authority is a legitimate expert on the subject.
  2. A consensus exists among legitimate experts on the matter under discussion.
Subsequently, if an appeal to authority doesn't meet the aforementioned prerequisites, then chances are the appeal is fallacious. What this means is, if the authority lacks the expertise to be considered an authority on that subject, or else, the authority is a minority who holds a belief radically opposed to the general consensus, then chances are the authority is invalid. In which case, the argument based on that single authority would be invalid--thus rendering your position invalid.

Sunday, October 2, 2011

The essence of moral reasoning, part 3: informed decisions

In my previous post in this series on morality, I talked about the biological underpinnings of our moral judgments, and argued that variances in the development of "empathy circuits" in various regions of the brain can powerfully shape the manner in which we make moral decisions, and that in our natural environment we may experience a conflict between the emotional circuitry in our brains and our rational faculties, which makes moral reasoning more complex. For the final post, I want to turn to the rational component of moral judgments.

There's a question regarding morality that is commonly posed to non-believers: "If you don't believe in an objective, transcendent and absolute moral authority, how can you say that the behavior of the Nazis was wrong?"

False morals

There are really two components here. The first is that what the Nazis did – treat people as mere objects – requires an erosion of our empathetic circuitry. Save those who suffer from abnormalities in various brain regions affecting empathy, it is simply not in our nature to be cruel to others; in fact, we have very specific, involuntary biological responses to seeing others in distress in which we experience many of the same symptoms that the other is showing. This response, however, can be temporarily eroded – we can be "de-conditioned" of our natural empathy.

The second component has to do with the more rational component of moral reasoning. Although it is in our nature to desire fairness and to feel compassion, we must reconcile those feelings with objective information about the natural world. So in forming rational moral judgments, it becomes absolutely vital that the information to which we have access is accurate.

A Nazi cold-water immersion experiment
And that, quite simply, forms a solid foundation upon which to reject "Nazi morality": the beliefs underpinning the Nazi's attempt at global domination and extermination of Jewish people are false. The German people were not a genetically superior "race" of people, but were every bit as human as the Jews they so villainized. The notion that the Jews were partly, if not entirely, responsible for Germany's economic woes was similarly pure nonsense. That's how you get Nazi morality: you have people who passionately believe information that is patently false. It's quite plausible that many Nazis, if not most, took no delight in the suffering of other people; but, by adopting the false belief that Jews were not actually people, they were able to overcome their natural human empathy, to the point that great atrocities were committed.

Since we recently passed the 10th anniversary of the 9.11 attacks, they will serve as a similar example. The bombers were not, in their own minds, villains; on the contrary, they viewed themselves as righteous soldiers in God's army. How can we say they were morally wrong? Easy: because they were factually wrong. False beliefs such as racism, sexism, nationalism, and religious fundamentalism can be flatly rejected as immoral precisely because they are indeed false.

I'll provide one more example. The journalism show Vanguard recently documented the anti-gay culture in Uganda, and showed that evangelical pastors were spreading false information about the behavior of homosexuals that incited outrage from congregants (view the full episode here). It's entirely plausible that such people are true believers and are not knowingly spreading false information, but it highlights a central point to my post: sound moral reasoning is dependent on accurate information.

Making informed judgments

It is for this reason that the pursuit of science is so important to our moral development. Many who treat others cruelly may not be abnormally low on the "empathy bell curve" I mentioned in the previous post; instead, they may sincerely believe that they are acting in the best interest of those they love; any erosion of their empathy circuitry, such as when Nigerian pastors cruelly exile children under accusations of witchcraft, is most likely temporary and reversible since those suffering from abnormalities in the brain comprise a relatively small portion of the population. Many such African nations are bereft of good science education, which will powerfully and adversely affect its people's ability to form rational moral judgments.

It's important to note that rooting our moral reasoning in accurate information provides a sound, non-arbitrary means of making moral judgments. By understanding how empathy works at the level of the brain, we can understand how our emotions inform our behavior and mitigate our rational judgments; and by valuing accurate information about the world around us, we can root our moral reasoning in objective truths, rather than being subject to the arbitrary whims of ideological falsehoods.

The essence of moral reasoning, part 2: making moral decisions

In my previous post on morality, I argued that simply saying that people are inclined to be "evil" fails as an explanation for human cruelty – it not only fails to take into account certain facts about our biological inclination toward empathy, but it leaves important questions about how we make moral decisions – and how our empathetic hard-wiring can be eroded – unanswered. I touched briefly on the fact that many of our "moral" decisions are made impulsively, and we reason about them retroactively. In this post, I want to examine more thoroughly some of the processes involved in making moral decisions – including how our empathetic nature can both influence us and be eroded.

Empathy on the brain

In his excellent book The Science of Evil, Cambridge psychologist Simon Baron-Cohen discusses the many regions of the brain that are associated with our ability to empathize with others. What's fascinating is that damage to specific regions of the brain cause empathy to malfunction in highly specific ways. Damage one part of the brain, and we can lose our ability to feel any empathy at all (sociopathology); damage a different part of the brain and we may be able to feel empathy, but be confused as to how to react appropriately; damage yet another different part of the brain and we may have difficulty reading facial expressions and accurately inferring others' emotional states.

The list goes on, but what this shows is that the physical state of our brain has a powerful effect on our ability to make moral decisions. If we can't feel empathy or accurately understand others' emotional states, for example, then our decisions will be more utilitarian and egocentric. This is not speculation or hypothesis, either – it is well documented in the behavior of those suffering from personality disorders.

The causes of personality disorders appear to be combinations of nature and nurture – something which may seem obvious, but is now well substantiated with research. Abuse and neglect during childhood can have an irreversible effect on the development of the brain which manifests in antisocial behavior during adolescence and adulthood. This has important implications: the deck is not stacked the same for everyone. Empathy exists on a bell curve, with individuals at one extreme being highly extroverted, sensitive, and compassionate; and individuals at the other extreme being literally incapable of feeling empathy. It's beyond dispute: our biology has a powerful influence on how we make moral decisions.

The brain in the environment

Of course, our brains don't just sit in vats all day; they're constantly bombarded with sensory input from our environment. We live in an environment in which competition over limited resources influences our moral reasoning. Much like soldiers trained to de-humanize their enemy, we can be conditioned to overcome our basic human empathy. And even if we are relatively normal on the empathy bell-curve, desperate situations may influence us to temporarily repress our empathy for others.

Our moral decisions take two forms: the impulsive, emotionally-driven reactions I mentioned previously; and moral reasoning, in which we attempt to dispassionately judge what is fair. The famous Trolley Problem illuminates the conflict between these two broad reason:

In the first scenario, subjects are presented with a trolley on course to kill five people; with a flip of a switch, the trolley can be re-directed to another track, where one person will be killed. Most individuals immediately judge that it is better to throw the switch and kill one instead of five.

In the second scenario, there is again a trolley headed toward five unfortunate souls. This time, you are on a bridge where a large man is standing. If you push him off the bridge, his corpse will stop the trolley.

In the second scenario, most respondents hesitate – and it is precisely that hesitation which betrays the fact that our moral decisions are not entirely rational (quite the contrary, in fact). In utilitarian terms, both situations are identical; but the second scenario requires us to directly harm a bystander, which causes the empathic circuitry in our brains to remind us that it is unfair to hurt another human being. Interestingly, people low on the empathy bell curve due to lack of development or damage to parts of the brain responsible for empathy (their "empathy circuitry") do not hesitate, since for these individuals all moral decisions are primarily utilitarian.

So we now know that emotions heavily influence our moral decisions, and that individuals whose empathy circuitry in their brains have been adversely affect by genetics and/or their environment will not make the same moral decisions as most of us simply because they do not feel a compulsion to nurture others, to ease or prevent their suffering, or to otherwise respond to their distress. They are unlikely to value fairness or self-sacrifice, as their inability to empathize with others creates an egocentric form of moral judgment. Since moral norms are concerned with how we ought to behave, it's vital that we recognize the pivotal role our biology plays in shaping our relationships with others, that we may properly understand how moral proscriptions are derived.

In the final post in this series, I'll get away from the emotional component and talk about moral reasoning specifically, and how we can use information to make non-arbitrary moral judgments.

The essence of moral reasoning, part 1: why "evil" fails

In my previous post about morality, I argued that all moral reasoning requires a subjective value judgment – that is, rather than adhering to some objective standard which tells us whether an action is unequivocally right or wrong, we examine each situation contextually and, based on the available information, decide whether an act is right, wrong, or somewhere in between. I also argued that our reasons for behaving morally are rational and non-arbitrary. Over the next three posts, I'll talk about how we make those moral decisions and how we reason about them.

The evidence from biology is unambiguous: certain behavioral tendencies are hard-wired through our evolution. We are, more often than not, cooperative, empathetic and reciprocally altruistic. Save for sociopaths, we tend to feel empathy and sympathy for others who are suffering. Of course, people also behave badly. We can be selfish, ambivalent, or cruel. We can be conditioned to erode our natural empathetic connection to others, to the point of barbarism.

The conventional answer to this dilemma is more or less the following: people behave that way because they're evil. Perhaps we're simply inclined to do evil because, well, that's what we are. But as an explanation, this is a non-starter. It fails to account for the fact that most of the time, we are empathetic, altruistic and cooperative. While stories of people behaving cruelly make for captivating news, they do so precisely because such behavior is not the norm. There is something unusual, something perversely remarkable about those whose sense of empathy has been eroded – and that is precisely why we react with shock and horror at the abject cruelty of things like Nazi medical experiments, US military officers torturing prisoners at Guantanamo Bay, or Islamic fundamentalists throwing acid on the faces of women. Were "evil" simply the norm of human behavior, we'd be much more surprised to see an act of goodwill.

But what I'll dub the argument from evil fails in a more important way: it doesn't accurately account for how we actually make moral decisions. Broadly speaking, there have been two competing theories in the behavioral sciences to explain morality. The first is veneer theory. This suggests that evolution has left us as cruel, selfish, and inclined to mistreat one another. It is only through our higher capacity of moral reasoning – perhaps our ability to understand a religious or legal "moral code" – that we have been able to overcome our innate destructive tendencies.

Veneer theory leaves many important questions unanswered. If it is only through moral reasoning that we have been able to overcome this innate evil, how did our species – and our evolutionary ancestors – survive long enough to develop such a moral code? Certain social norms, such as prohibitions against assault, theft, murder and perjury, are integral to the fundamental cohesion of any human society. Had those in primitive human (or proto-human) societies simply given in to every cruel or selfish whim, they never would have been able to coexist. Reciprocal altruism has always been required for us to find food, to protect ourselves from predators and the elements, and to raise children.

In his book The Age of Empathy, primatologist Frans De Waal expounds:
Don’t believe anyone who says that since nature is based on a struggle for life, we need to live like this as well. Many animals survive not by eliminating each other or by keeping everything for themselves, but by cooperating and sharing. This applies most definitely to pack hunters, such as wolves or killer whales, but also our closest relatives, the primates. In a study in Ta├» National Park, in Ivory Coast, chimpanzees took care of group mates wounded by leopards, licking their blood, carefully removing dirt, and waving away flies that came near the wounds. They protected injured companions, and slowed down during travel in order to accommodate them. All of this makes perfect sense given that chimpanzees live in groups for a reason, the same way wolves and humans are group animals for a reason. If man is wolf to man, he is so in every sense, not just the negative one. We would not be where we are today had our ancestors been socially aloof. What we need is a complete overhaul of assumptions about human nature. [p.6]
Veneer theory further fails to account for the fact that even young children have been shown to display empathy. In a study of children ages 7 to 12, researchers at the University of Chicago found that the empathetic response was present even though the children had limited understanding of moral reasoning:
"This study is the first to examine in young children both the neural response to pain in others and the impact of someone causing pain to someone else," said Jean Decety, Professor in the Departments of Psychology and Psychiatry at the University of Chicago.
The programming for empathy is something that is "hard-wired" into the brains of normal children, and not entirely the product of parental guidance or other nurturing.[2]
Finally, veneer theory fails to account for a very important fact – one which I will expand on in part 2: many of our moral decisions are made involuntarily. If we spot a small child wandering in the middle of a busy street, we impulsively rush to protect her. We do not pause to contemplate the cost/benefit to ourselves or society as a whole – it is only after the event that we conjure up rationalizations for our behavior (this phenomenon is illustrated in the Trolley Problem, which I've discussed here). Were cruelty our first inclination, as veneer theory suggests, we would not act with compulsive compassion.  

The facts are unambiguous: we must acknowledge that empathy and altruism are hard-wired and integral to the very survival of our species. We can think of this as the second theory of moral behavior: what I'll dub the grounded theory of morality, to reflect its bottom-up development. But clearly, hard-wired feelings of empathy or an inclination toward reciprocal altruism cannot fully explain our moral behavior. Somehow, these inclinations can be eroded to the point that we are capable of great acts of cruelty. We can, as a society, make rules that reflect a desire for equality and peace, or we can impose militaristic rule and enact barbaric punishments for petty crimes. In the next post, I'll discuss how evolutionary hard-wiring interplays with our environment, and how we reason about moral values.

Morality is subjective

In the previous post I argued against the notion of "objective morality". Now, I want to turn to the subjectivity of moral judgments. All moral judgments are, by necessity, subjective. But that doesn't mean our concept of right and wrong is arbitrary, nor does it mean that our judgments themselves are arbitrary. To illustrate this, I'm going to revisit an example I used in the previous post.

First, I want to suggest that there are three broad "tiers" of moral judgment; an act can be:

  1. Forbidden
  2. Permissible 
  3. Obligatory

Is lying an objectively immoral act? The Biblical God explicitly forbids it in the 10 Commandments, and most of us believe, in general, that lying is wrong. But it doesn't take much effort to imagine a circumstance in which lying is either permissible or even morally obligatory –unambiguously the right course of action.

In Nazi-occupied Poland, families sympathetic to the plight of Jews would hide Jewish families in the attics, walls, or basements of their houses. When Nazi officers came around inquiring as to the whereabouts of these Jews, the families lied to protect them.

Most reasonable people would agree that in this circumstance, it was not merely permissible to lie – lying was the morally obligatory course of action. If this is true, it means that the act of lying cannot be intrinsically, objectively wrong; rather, we make subjective value judgments as to the "rightness" of the action depending on the circumstance. If lying were objectively wrong, it would always be wrong.

It's easy to imagine this with virtually any other act. Is it moral to indiscriminately kill civilians en masse in a time of war? We've evolved our weapons of warfare to minimize civilian casualties – we use laser-guided bombs and missiles, precise rifles fired by trained marksmen, etc. If we had no care of killing the innocent, we could simply drop as many nukes as it took to wipe our enemies off the face of the earth.

But in World War II, the United States dropped two nuclear bombs on Japan. In those two explosions, hundreds of thousands of people died – most of them civilians. And the ones that were evaporated were the lucky ones – many more suffered slow, excruciatingly painful deaths from radiation poisoning. But in this case, the US military had made a subjective value judgment – that the show of force of the atomic bombs would force Japan to surrender, ending a war that, if protracted, would likely escalated to a full-scale invasion of Japan and cost millions more lives.

Regardless of whether one agrees that this action was either wrong, permissible, or obligatory, the fact remains that it was an act of genocide that was circumstantially justified through subjective value judgments. As horrible as we generally think genocide is, even genocide is not objectively wrong. If it were as simple as saying something like "lying is objectively wrong", then we would quickly run into an impasse as various objective moral tenets conflicted with each other. The Nazi example is a fine one; is it not also wrong to passively allow the abuse and murder of other humans when it is within our power to prevent it?  While surrendering our power to help others is an act of omission, and lying is an act of commission, I think most reasonable people would agree that in this case, the act of surrender would be the greater moral crime, and lying was the right thing to do.

All moral actions require subjective judgments which take into account external factors that influence whether an act is forbidden, permissible, or obligatory. No act exists in a vacuum where it can be considered absolutely and objectively right or wrong. Only one issue remains: how do we determine, then, what constitutes right and wrong? As I've already suggested, though our judgments are necessarily subjective, our reasoning is not arbitrary. I'll be doing a third post on morality soon (hopefully this weekend), and the nature of moral reasoning will be its subject.

Objective morality does not exist

It's been parroted by just about every Christian theologian I've ever encountered (even the armchair kind): Without God, anything is permissible. God is the only source of objective moral law. If there is no God, then there is no objective morality, and no one can say with any authority or rational certainty that any given act is patently immoral.

So, why believe a "moral law" exists in the first place? For some reason, we want to be treated fairly. We want our autonomy respected. Even when we treat others unfairly, we usually still want to be treated fairly ourselves. There's some intuitive sense in us that constitutes what is right and wrong. If we're asked why it's wrong to indiscriminately kill and eat infants, our answer tends toward, It just is.  This intuitive understanding of moral behavior indicates that there exists an objective moral law to which we are subject. If such an objective moral law exists, it must come from a moral law giver whose authority is absolute and infallible – God.

I submit that what Christians really believe is actually just another form of subjective morality. Nobody really believes in ultimate moral absolutes.

Righteous killings

William Lane Craig has recently defended, again, the Slaughter of the Canaanites[1]. In this charming Bible story, almighty God orders his holy army to mercilessly slaughter everyone in Canaan. God explicitly tells them to leave no one alive:
However, in the cities of the nations the LORD your God is giving you as an inheritance, do not leave alive anything that breathes.  Completely destroy them—the Hittites, Amorites, Canaanites, Perizzites, Hivites and Jebusites—as the LORD your God has commanded you. [Deut 20:16-17]
It should be noted that is one of many times God commands his righteous army to kill the shit out of everyone. In the judgement of Israel in the book of Ezekiel, God's instructions are even more explicit (emphasis mine):
Now the glory of the God of Israel went up from above the cherubim, where it had been, and moved to the threshold of the temple. Then the LORD called to the man clothed in linen who had the writing kit at his side and said to him, “Go throughout the city of Jerusalem and put a mark on the foreheads of those who grieve and lament over all the detestable things that are done in it.” As I listened, he said to the others, “Follow him through the city and kill, without showing pity or compassion. Slaughter the old men, the young men and women, the mothers and children, but do not touch anyone who has the mark. Begin at my sanctuary.” So they began with the old men who were in front of the temple.[Ezekiel 9:3-6]
Clearly, Yahweh does not mess around. But wait! Doesn't the idea of deliberately slaughtering children offend our moral sensibilities? Isn't this barbaric and... well, evil? Craig has a different explanation. First, he recounts his previous defense, which I have addressed on this blog [2]:
My argument in Question of the Week #16 is that God has the moral right to issue such commands and that He wronged no one in doing so.

Then he adds this juicy tidbit:
There is one important aspect of my answer that I would change, however. I have come to appreciate as a result of a closer reading of the biblical text that God’s command to Israel was not primarily to exterminate the Canaanites but to drive them out of the land.
It is therefore completely misleading to characterize God’s command to Israel as a command to commit genocide. Rather it was first and foremost a command to drive the tribes out of the land and to occupy it.

Well, I have two objections. The first is that it's not, y'know, true. The scripture explicitly tells them to destroy "anything that breathes". If that's not a command for genocide, well, I don't know what is. But the second problem is that it's sort of like saying that if a murderer entered your house and killed your family, it was your fault for not getting them out of there fast enough. It's blaming the victim.

I am, frankly, much more interested in what Craig said in his first response: that God was morally justified in ordering the genocide. Something tells me that if this weren't creating a little cognitive dissonance for Craig, he wouldn't have conjured up his charitable re-interpretation. It's hard to really, honestly think that killing innocent people en masse is a good thing.

This raises a bigger issue: are horrible things okay if God commands them? The answer, according to Craig at least, is a resounding yes. However horrible we might find the indiscriminate slaughter of children, God had sufficient moral reason for doing so.

What makes something immoral?

But this creates a great conundrum for Christians: if any atrocity can be morally justified by God's command, then no act is absolutely wrong. What Craig is arguing is not that genocide is okay all the time, but that there was a mitigating circumstance in which it was the right thing to do. In other words, there is nothing about the act of murdering children that, in itself, is intrinsically wrong. Because if it were absolutely wrong, then even God would not be able to command it. Remember when William Lane Craig said this (emphasis mine):
God's moral nature is expressed in relation to us in the form of divine commandments which constitute our moral duties or obligations. Far from being arbitrary, God's commandments must be consistent with his holy and loving nature. [3]
If that second sentence is true, then God cannot command us to do something that is morally wrong; thus, the mass child killing must have been right, since that is what God commanded. But that erodes the entire concept of what "objective morality" is supposed to be. Presumably, there is a moral law which we all intuitively understand and to which we are all bound. Let's go back a moment, and listen to how C.S. Lewis describes moral law in Mere Christianity:
It seems,  then,  we are forced to  believe in a real Right  and Wrong.
People may  be sometimes mistaken about them,  just as people sometimes  get
their sums wrong;  but they are not  a matter of mere taste and  opinion any
more than the multiplication table.
But if even killing children can, in certain circumstances, be considered an act of good, then what basis is there to assert "it is wrong to kill children" as an objective moral tenet?

Here's a more obvious example. Lying is forbidden in the Ten Commandments. But few of us would object to those who, in Nazi-occupied Poland, lied to authorities to protect the lives of Jewish people. In some circumstances, lying is the most compassionate thing to do. This means that lying cannot be objectively, absolutely wrong. There are circumstances in which we recognize it as not only permissible, but even morally obligatory. Lying is not absolutely wrong. Neither is taking someone's life. We can probably imagine any atrocity, no matter how disgusting and awful, and then imagine another circumstance in which it was the lesser of evils. That is precisely what Christians do when they are defending genocide commanded by God: they're arguing that, while not pretty, it was the best and most moral course of action.

This simply means that morality is subject to God's whims. The Christian is merely positing another form of subjective morality, in which no act is absolutely, fundamentally wrong; instead, the "rightness" of an act is contingent on whether God commands or condemns it. And, of course, God can change his tune; he can say, "thou shalt not kill", or he can say, "kill, without showing pity or compassion". Is killing objectively wrong? Is this an absolute moral law? If so, then God is evil to command it; if the act can be circumstantially good because God commanded it, it cannot intrinsically be objectively and absolutely wrong.

Subjective does not mean arbitrary

Christians who argue against a non-theistic ground for moral behavior, going all the way back to C.S. Lewis, are making a fundamental folly: they are conflating subjective with arbitrary. Morality is not objective. Even Christians, in practice, do not believe such a thing. We all experience moral impulses and moral reasoning subjectively. However, we have non-arbitrary reasons for adhering to norms of moral behavior. There are rational reasons for treating others fairly, for doing acts of goodwill, and even for sacrificing ourselves for the good of others. I won't tread on the subject here, as this post is already quite lengthy, but a fine primer can be found here.

The very notion of grounding morality in God's commands necessarily makes morality arbitrary. If even the indiscriminate killing of children as a part of a hostile military conquest can be viewed as circumstantially moral, then what act can't be circumstantially moral? Truly, with God, everything is permitted.