Dear Mr. Chick,

You probably don't know me, but I'm writing to send you my thanks. I used to be a hardcore, evil, godless atheist, but after reading some of your wonderful Christian fundamentalist cartoon tracts, I've realized just how wrong I've been. Now I know that there is a God who loves me and who died for my sins, and that his name is Jesus Christ. I also now understand that playing Dungeons & Dragons too much will lead to you being initiated into a witches' coven and taught how to cast real spells; that Roman Catholicism is a Satanic cult and keeps its followers in line with demonic Egyptian death cookies; and that Jesus is the one who holds the protons together in atomic nuclei. (I always knew those godless physicists were just making it up when they talked about so-called "gluons"!)

Thanks to you, I'm ready to accept Jesus Christ's free gift of salvation and be washed clean by his precious blood. However, I can't do that just yet. There's one other thing I have to do first, but I'm having a problem. I thought I'd write to you in the hopes that you'd offer me some advice. Please allow me to explain.

One of your tracts which made the greatest impression on me was the one titled "The Contract". In this tract, an impoverished farmer makes a deal with the Devil to sell his soul in exchange for the money he needs to keep his farm. He receives the money, as promised, and uses it to do just that. Years later, he has a last-minute conversion to Christianity on his deathbed and goes to Heaven anyway.

I think this is a fantastic idea! Forget all those phony get-rich-quick schemes - here's one that really works. All I have to do is sign a contract with Satan, promising him my eternal soul in exchange for enormous worldly wealth and power, and then repent and turn to Jesus. That way, I can break the contract, get to enjoy eternal bliss when I die, and still get to keep all the cool stuff in the meantime! There's no downside! And I have you to thank for the inspiration. (That guy who told everyone not to "lay up treasures for yourselves upon the earth" was a real sucker! He went about this whole Christian thing all wrong. I guess he just wasn't as good at seeing these opportunities as us.)

Anyway, that's my foolproof plan - but it's hit just one snag. Namely, I can't get the Devil to show up and offer me the contract. I've tried everything I can think of to draw his attention - stamping my foot in public and audibly muttering, "I'd sell my soul for a billion dollars!"; listening to rock-and-roll music; reading demonic books like Harry Potter and The Origin of Species - but so far, I've had no luck.

Mr. Chick, I'm sure I'm not the first person to have this idea. I bet a great Christian evangelist like yourself has already thought of it - heck, you wrote the tract! I'm thinking you must know how to get the Devil's attention, and I bet you've already tricked him into giving you all kinds of free stuff. (Don't worry, I won't horn in your racket. I know the whole international, multimillion-dollar comic strip ministry was your idea. I'll ask him for something else!) Can you give me any tips? Pointers? What am I doing wrong?

If you get this letter, please rush your reply. As you can imagine, time is critical here - if I sign the Devil's contract but then die before accepting Jesus as my personal savior, I'll be eternally damned, and I don't want that. But I also don't want to get saved before getting my hands on all the worldly goods Satan can give me. The way I see it, Satan is God's enemy and I'd be cheating him out of all that stuff, so it has to be okay. I know I can't take it all with me, but that doesn't mean I can't enjoy it while I'm here, right?

Thanks in advance for your anticipated assistance.

Sincerely,

Adam Lee
http://www.daylightatheism.org

Inspired by a recent post on Philosophy, et cetera, I want to talk a little about zombies and what they imply for a materialist theory of the mind.

When I say "zombie," I don't mean the shambling, flesh-eating undead of horror films. This thought experiment is about philosophical zombies, which are a different beast altogether. The philosophers' zombie is a hypothetical creature which, to all outward appearances, is indistinguishable from an ordinary human. The difference is that they lack phenomenal consciousness - they lack qualia.

Qualia are the subjective sensory perceptions of our inner mental life. We see colors: the redness of red, the greenness of green. We hear tones, sharp or high-pitched or dull or low. We taste flavors, salty or bitter or sweet. We feel emotions like joy, anger, or sadness. Zombies, by contrast, have none of these experiences. They are not truly conscious of anything, any more than a stone is conscious, but they act exactly as if they were. A zombie can duck a thrown baseball or write a restaurant review. Point a gun at one and it will flinch and act as if it were afraid.

What does such a bizarre idea have to do with atheism? The answer is that some prominent philosophers claim that zombies are a conclusive disproof of any strictly naturalistic theory of how the mind functions. The train of argument usually goes that zombies are not a metaphysically impossible notion; it involves no self-contradiction to imagine their existing. If they are not self-contradictory, then they are possible. If they are possible, then we could hypothetically build one - a sophisticated robot, let's say. Such a being would act with rationality and apparent intelligence, yet lack consciousness. But if it's possible to be an intelligent, rational being without consciousness, the question is, why aren't we zombies? What makes us different from the robot? The answer, they say, is that there must be a supernatural component to the mind, in other words, a soul. This supernatural component is what gives us our consciousness, our qualia, whereas a being lacking that component could never truly be conscious no matter how much mental processing power it might have.

The problem with zombies, as with many philosophical notions, is that they do not truly prove a point but simply play on people's differing intuitions about what is possible. No obvious self-contradiction arises when we imagine a zombie, I grant. It is logically possible for such a thing to exist. But that does not mean that zombies are possible in our world, under the laws of physics that hold sway here. Our ability to imagine them is no disproof of this. We, fallible humans, are not cognizant of all the laws of physics, much less their almost infinitely complex hierarchy of ramifications. An intelligence like Laplace's demon, with perfect knowledge of the universe, might well see some consequence of physical principles which we overlook, and which renders zombies impossible in our world.

Consider a similar example. Just as dualist philosophers claim they can imagine creating a zombie, I claim I can imagine creating a perpetual motion machine. I couldn't tell you exactly how to build it, just as no one can say exactly how to build a zombie, but I can readily imagine some marvelous machine - blinking lights, coils of wire conducting electric arcs, spinning flywheels, a big brass switch - that, once it's powered up, begins producing free energy out of nowhere. No self-contradiction arises when I imagine this. But does that mean we can actually build one? Have I just disproved the laws of thermodynamics without getting out of my armchair?

Obviously not. Though we may think we can imagine a working perpetual motion machine, reality is bound to disappoint. So far, every attempt to build one has ended in utter failure, stymied by some physical principle they failed to take into account. The laws of our universe, it appears, interlock in such a way as to perfectly rule out the possibility of perpetual motion machines. There is no loophole where an inventor, however clever, can slip through. It only seems possible because our imaginations do not take into account the critical details that any practical attempt cannot avoid.

The dualists, I believe, are in the same boat. They may think they can imagine zombies, but that doesn't mean they're actually possible. Indeed, I suspect the opposite is more likely true: any creature complex enough to behave with all the creativity and adaptability of a human being would have to have consciousness and qualia, or something very much like them.

After all, how could a zombie dodge a thrown baseball, unless its eyes (or cameras) conveyed images of nearby objects; unless those images were in some way converted into an internal model of the world; and unless that model contained some data stream or symbol which represented a small, round, rapidly approaching object? How could a zombie write a restaurant review unless its chemical sensors were linked to a sophisticated mapping of what readings correspond to what flavors and the many subtle ways in which various combinations could interact with each other? How could a zombie convincingly simulate fear unless it had a wide-ranging ability to keep track of events in the external world and infer which ones could pose a threat to its continued existence?

It is not at all obvious to me that a being with such a sophisticated repertoire of memory, understanding and perception could fail to be conscious. In fact, I strongly suspect the opposite: any being with this capability would have to be conscious, given the physical laws that hold in our world. Consciousness is not an optional add-on, but an inevitable product of a certain degree of cognitive sophistication. In particular, I believe the ability to explicitly represent one's own self in one's mental catalog of objects, and to introspect one's own internal information processing - which, again, a zombie can do - is a vital building block of true consciousness as humans possess it, if it is not consciousness itself.

The dualists assume that an intelligent being could fail to possess qualia, and therefore conclude that intelligence and consciousness are separable. But this claim is an example of the fallacy of circular argument. If you assert that it's possible to hold everything else about the world constant, but subtract consciousness, then you're not arguing for dualism, you're assuming dualism! The conclusion which you wish to reach is already contained in the starting assumptions you feed into your argument. Whether consciousness is an inevitable outcome of the working-out of physical laws inside intelligent brains, or whether it's an unnecessary epiphenomenal accompaniment, is the very thing at issue. I argue that, contrary to some people's intuition, consciousness and intelligence are in fact not separable. I can't prove it; but neither can the dualists prove that they are.

The only remaining question, which I admit is a vexing one, is: why qualia? Why does consciousness have any subjective character at all? The way in which our minds represent characteristics of the external world as ineffable interior perceptions does seem strange, and not like most other phenomena we encounter. It does indeed seem difficult to imagine that any science, however advanced, could explain precisely how such subjective experiences arise from the collisions of atoms inside the brain.

But our inability to imagine it, at this point in time, is no proof that it's impossible. The existence of life was also once considered to be an impenetrable mystery, inexplicable except by postulating a supernatural "vital force". Yet life has since been shown to have an explanation comprehensible in terms of physical laws. (Overcoming Bias writes about "encapsulating the mystery as a substance" - an apt description of the situation.) I see no reason to believe that qualia will prove to be any different. Though they may seem to be a fundamentally different kind of thing, that's just an artifact of our present ignorance. Most likely, qualia arise from the physical laws of the cosmos no less than any other natural phenomenon. We don't understand precisely how - and maybe the mysterians are right, and we never will - but still, that is no proof that it is impossible.

Last year, around the time I inaugurated my Poetry Sunday series, I contacted Prof. Philip Appleman to ask for permission to reprint some of his work which I'd seen in Freethought Today. He graciously assented to my request, and even said a few kind words about "The Gods", my own brief foray into free verse, which I had the brashness to ask for his opinion on.

He called my poem "hopeful," which was an honor to me, but there was one other thing he said which I've been dwelling on - that he was pleased because hopefulness, these days, is a rare virtue. And, I have to say, I understand very well what he meant.

I've been reading more science fiction this past year or two, and one major theme I've noticed is that we have so many dystopias. I've lost count of how many fictions I've read where things fail, where everything goes disastrously wrong, where humanity shatters itself or dwindles away. Why, I wonder, are we so obsessed with our own destruction? Why is it that we seem to delight in imagining the most horrendous fates possible? Writing like this can serve as a warning, I know. But shouldn't we also want something to inspire us, to give us hope? Shouldn't we want to set a goal we can aspire to?

Part of it may be a contingent fact, a sign of the times. Every time there is war, disaster, uncertainty, people feel more pessimistic about the future, and a spasm of despair passes through humanity's literary output. And so far, the first decade of the twenty-first century has given the world a great deal to be anxious about - the resurgent threat of terrorism, the growing danger of global climate change, rising energy prices and food instability, and increased tension in many historic trouble spots. Perhaps the pessimism of our creations is just a symbol of what's on everyone's mind?

But if that's the explanation, we have to face the fact that the world has always been a troubled place. There was never a time in human history when the globe was universally peaceful and life was everywhere good. On the contrary, there have always been wars, famines and disasters; there has always been corruption, greed and poverty; and people have always been lazy, ignorant, corruptible, selfish and credulous. In fact, one might argue that war and violence has taken a greater toll on humanity in every era, culminating in the world wars of the twentieth century, the bloodiest and most destructive conflicts humanity has yet witnessed. Is this a trend which we can expect to continue? As the twenty-first century proceeds, we've seen the rise of several new nuclear powers, the spread of virulent religious fascism, a swelling human population testing the limits of what the planet can sustain, and the natural resources upon which we all depend growing increasingly stretched and thin. It's entirely possible that this century may witness truly apocalyptic wars, with the most awful loss of life ever. And it's not inconceivable that, if such wars happen, even the survivors may be left so bloodied and fragmented as to herald the beginning of a long, slow fall back into darkness - the dystopia of our grimmest fantasies, this time enacted in reality.

Even beside these nightmare scenarios, the more mundane, chronic problems of our planet can still seem overwhelming. Every day, millions of people around the world languish in poverty, feel the bite of hunger, and suffer from entirely curable epidemics. Millions more live in fear under totalitarian governments or in war-torn failed states. Even where life is relatively peaceful, sometimes it seems as if the masses are content to live in stupor, willing to march to war at the command of jingoistic politicians or trade precious, hard-won liberties in exchange for pop-culture anesthesia. Granted, there are brave souls who labor their lives to improve the situation; but against the pervasive backdrop of human misery, and the widespread apathy and self-interest that permits it to continue, their efforts sometimes seem futile. The problems that face us have their own inertia, and some days it seems towering, far too massive to shift. Are there really enough people who care to make a difference?

Then again, perhaps I judge humanity too harshly. I have to admit that I understand why so many people don't choose the course of activism. When you see a problem in the world, or something that disturbs your conscience, you have three options. You can take action to make it better, but that requires time and effort. If you believe it can be fixed but don't take action to do so, this causes uncomfortable moral dissonance. By far the easiest course of action is to persuade yourself that it's a bad situation, but there's really nothing that can be done, or that it doesn't involve you. The course of apathy is soothing and keeps people's consciences intact in the face of evils they can do nothing about. Once again, it's a Prisoner's Dilemma: the more who opt out of action, the greater the pressure becomes on everyone else to do the same.

I am an optimist by nature and temperament, but even I keep being pulled back by the realities of our world. There are days when the effort of caring seems futile, pointless, and the temptation to write it all off and let humanity build its own pyre is strong. I haven't yielded to it so far, but how can I justify being hopeful? Is there any justification for an informed optimism that confronts the daily reality of suffering and is not bowed under?

I believe that there is. Optimism can be and often is caricatured as a starry-eyed, head-in-the-clouds naivete about "the way things really are", as opposed to unflinching, clear-thinking cynicism. But I much prefer a tough, informed optimism, one that takes in all that is wrong with the world and accepts things as they are, yet does not proclaim that losing hope is the appropriate response.

Pessimism is too easy. In a way, it's cowardly. As I said, the pessimist's choice can be a soothing one, a position which reassures its holder that apathy and inactivity are morally acceptable. After all, if you believe that failure is inevitable, it relieves you of the responsibility to have to do anything. To be frank, it's easy to believe the worst of everyone and everything. Even a foolish optimist risks disappointment; the hardcore pessimist never does.

In that sense, pessimism is a self-fulfilling guarantee of failure. True pessimists believe that failure in a worthy endeavor is impossible, so they don't participate; and if that endeavor should fail because of their lack of participation, that becomes a self-justifying excuse not to participate in the future. By contrast, even an optimist will fail on occasion, but optimism, unlike pessimism, does not cause its own downfall.

The usual solution to a Prisoner's Dilemma is regulation by a higher authority, but there is none in this case. We can't force people to be dedicated to worthy causes or to care about the welfare of others. The only other solution is for individuals to freely step up and answer the call of need, and trust that their actions can inspire others to do the same. That's the goal I try to strive for. My optimism is not the sort that says success is inevitable, but merely that it's possible - and that this possibility is reason enough to try.

I don't deny the badness in humanity, but we possess many good and noble qualities as well. The naive optimists and the embittered cynics, both of whom deny one of these aspects completely in favor of the other, are both equally in error. The exact balance between our light and dark sides is a matter of dispute, but I'm inclined to say that the goodness of humanity must outweigh the evil. We couldn't have come as far as we have, built as much as we have, if that were not the case. We would never have risen above a state of anarchy. The goodness of people consists in many small, quiet acts, often overlooked against the backdrop of thunderous strokes of evil - but they are there, nonetheless.

And if you look at human history, we do see a trend of increasing moral knowledge and progress. It's not a steady climb, rather a zigzag rise with many backward steps and local reversions, but it is there. Our wisdom still lags our technological prowess, but that is growing as well. It's by no means guaranteed that the one will overtake the other in time. But neither is it guaranteed that this will not happen. The future is open, and we can write the outcome through our efforts. That knowledge - the knowledge that the story is not yet over, that we have the power to control our own destiny, and that we can still choose a good one - is what informs my optimism, and what gives me the continued motivation for hope.

Although abortion is stereotyped as the most controversial and divisive social issue there is, I think the moral issues at stake are actually fairly unambiguous. This installment of "On the Morality Of" will explain why.

Pared down to its essence, the moral question posed by abortion is a simple one: is an unborn fetus a human being, with all the moral rights and protections that pertain thereunto; or is it a non-human, an assemblage of cells, the existence of which may be terminated without wrongdoing?

The answer to this question, of course, depends critically on how you define a human being. Is a fetus a human being if it has a face, or arms and legs, or a beating heart? None of these criteria seem to me to be definitive. Being a human is far more than a matter of superficial physical appearance - we do not grant humanity to department-store mannequins, after all. Nor is humanity the mere arrangement of internal organs. If a person's heart or lungs are failing and they need to be kept alive by machinery, does that deprive them of their moral personhood? Obviously not.

What if we were to define a human being as a living organism which possesses a certain, characteristic set of genes? This definition seems somewhat closer, but again, I think it misses the mark. If humanity consists of being a living organism which possesses human DNA, then we would also have to grant personhood rights to HeLa cell colonies, or to fetuses with anencephaly (warning: disturbing image). More to the point, if a living thing with human DNA is human, then every single one of our cells should be considered to be a human in its own right, and the millions of them that are naturally sloughed off our bodies each day would constitute a holocaust of unthinkable proportions. Obviously, this is absurd.

I submit that there is one and only one defining characteristic of a person, one thing which sets us apart and gives us our unique moral worth. That thing is consciousness - the facility for self-aware thought. That is what most clearly differentiates us from all other species on this planet, and it is also what gives us the uniqueness and individuality that is rightly viewed as a key component of moral worth.

Taking consciousness to be the defining characteristic of humanity gives us a clear dividing line to use in deciding whether abortion is immoral. Ending the existence of something which does not possess the ability for conscious thought - whatever else it may be - is not the destruction of a human being. Ending the existence of something which does possess that ability is the destruction of a person. This is a solid, rational standard. It's a good sign that this position also neatly mirrors the common position on end-of-life care and euthanasia: once a human being has suffered brain death, or any other injury that results in the irreversible cessation of consciousness, they no longer possess moral personhood and we are under no obligation to ensure their physical continuance.

So, when does consciousness begin? This is a question which has an empirical answer. As Carl Sagan wrote on the topic:

Different kinds of mental activity show different kinds of brain waves. But brain waves with regular patterns typical of adult human brains do not appear in the fetus until about the 30th week of pregnancy—near the beginning of the third trimester. Fetuses younger than this—however alive and active they may be—lack the necessary brain architecture. They cannot yet think.

This boundary line - which is the same boundary line the U.S. Supreme Court drew in Roe v. Wade, although for different reasons - is a feasible and defensible standard. It safeguards the autonomy of the woman, and her moral right to exercise control over her own body and not be forcibly subjected to the risks and burdens of pregnancy, without compromising the important principle that every human life should be protected. If a woman wishes to obtain an abortion, it seems to me that half a year is more than adequate time for her to become aware of her pregnancy, make the decision to abort, and obtain access to medical services.

As Sagan points out, six months is actually a conservative boundary, since regular brain waves are often absent in fetuses. Also, it's conceivable that a fetus could possess them and still lack the ability for conscious thought. Nevertheless, it's still a good standard and not one we should seek to push. When we know, based on our physiological understanding of how the brain functions, that consciousness cannot exist, then no person is present and we are under no corresponding ethical obligation. However, if there's a rational possibility that consciousness may exist, then we should err on the side of caution and defend that life, just as it would be immoral to shoot into a closed box without knowing if there's a person inside. Of course, if continued pregnancy would pose a threat to the life or health of the mother, then terminating the pregnancy is an unambiguous matter of self-defense.

Until the capability for conscious thought exists, a fetus cannot have the same moral status as a person. Doubtless, the fetus is a potential person. But potentiality is not the same as actuality, and a person who only potentially exists cannot claim moral rights which match or supercede the rights of an actual, living, conscious person. (The language is imprecise here; in truth, a person who only potentially exists does not exist, and a non-existent person cannot claim anything. There is no one to make the claim.) Therefore, no harm is done when a woman aborts a pregnancy before this point. There is no person for harm to be done to.

Other posts in this series:

• On the Morality Of...

Today's Poetry Sunday features a few selections from the American poet Ella Wheeler Wilcox. Wilcox was born in 1850 in Wisconsin and soon acquired renown as a poet, becoming well-known for her writing by the time she graduated high school. Her poems were resolutely plain and optimistic, and though her simple, sometimes singsong verse was often scorned by critics, during her lifetime she was immensely popular among the public. Among the best-known quotes from her poetry are "Love lights more fires than hate extinguishes" and the well-known line, "Laugh and the world laughs with you; weep, and you weep alone" (from "Solitude"). Some of her many published works include Drops of Water (1872 - written in support of the temperance movement), Poems of Passion (1883), Poems of Pleasure (1888), and Poems of Sentiment (1906).

Though no friend of religious orthodoxy, Wilcox was not an atheist - she flirted with spiritualism, Theosophy, New Thought, and other New Age-like beliefs throughout her life, and grew distressingly attached to them after the death of her husband Robert, whom she repeatedly tried to contact from beyond the grave. Nevertheless, I think she deserves to be considered an honorary freethinker on the strength of poems such as "The World's Need", reprinted below.

The World's Need

So many gods, so many creeds;
So many paths that wind and wind,
While just the art of being kind
Is all the sad world needs.

Protest

To sin by silence, when we should protest,
Makes cowards out of men. The human race
Has climbed on protest. Had no voice been raised
Against injustice, ignorance, and lust,
The inquisition yet would serve the law,
And guillotines decide our least disputes.
The few who dare, must speak and speak again
To right the wrongs of many. Speech, thank God,
No vested power in this great day and land
Can gag or throttle. Press and voice may cry
Loud disapproval of existing ills;
May criticise oppression and condemn
The lawlessness of wealth-protecting laws
That let the children and childbearers toil
To purchase ease for idle millionaires.

Therefore I do protest against the boast
Of independence in this mighty land.
Call no chain strong, which holds one rusted link.
Call no land free, that holds one fettered slave.
Until the manacled slim wrists of babes
Are loosed to toss in childish sport and glee,
Until the mother bears no burden, save
The precious one beneath her heart, until
God's soil is rescued from the clutch of greed
And given back to labor, let no man
Call this the land of freedom.

From "Here and Now"

Stand not aloof nor apart,
Plunge in the thick of the fight.
There in the street and the mart,
That is the place to do right.
Not in some cloister or cave,
Not in some kingdom above,
Here, on this side of the grave,
Here, should we labor and love.

From "Settle the Question Right"

However the battle is ended,
Though proudly the victor comes,
With flaunting flags and neighing nags
And echoing roll of drums;
Still truth proclaims this motto
In letters of living light,
No question is ever settled
Until it is settled right.

...Let those who have failed take courage,
Though the enemy seem to have won;
If he be in the wrong, though his ranks are strong,
The battle is not yet done.
For sure as the morning follows
The darkest hour of night,
No question is ever settled
Until it is settled right.

Other posts in this series:

• Poetry Sunday

Over the past two months, I've written about the differing epistemologies of religion - where the individual's personal conviction is taken as a reliable guide to truth ("The Aura of Infallibility") - and science - where the assumption is that individuals are fallible and should work as a group to correct each other in a spirit of free inquiry ("Self-Correction").

The question I now want to turn to is this: How does a lay person tell the difference? Why should people who are not particularly educated in either religion or science - which is most people, after all - choose one over the other? More important, from our perspective, what reason do they have to make the right choice? Looking up "from the ground" at the two mountain peaks of science and religion, how can they tell them apart?

As we know well, science has far better evidence in support of its hypotheses. But to most people, examining both religion and science in the degree of detail needed to confirm that would be an enormous endeavor. And to what end? To decide an abstract philosophical point? It's no wonder that most people stay in the faith they're brought up in. Even if they wanted to find a different system of thought, just getting started might seem like an overwhelmingly difficult task.

From the outside, all belief systems seem similar. Creationists and other pseudoscientists often exploit this confusion. If they can put a man in a suit with letters after his name on stage, to argue against a different man in a suit with different letters, the audience will often assume both sides must be equally matched - even if what the creationist is saying is total nonsense to anyone who actually knows anything about the field being discussed.

So, what reason would a nonexpert have to choose science over religion as a way of understanding the world? I have three reasons to offer that even an outsider can appreciate:

• Science has a clear trend of progress. If, after several centuries or millennia, scientists were still divided into numerous squabbling camps, fruitlessly arguing over issues that had been in dispute since the beginning - then we might have reason to doubt that science produces an accurate view of the world.

But science, as any person can see, is not like this. Scientific disputes and arguments do occur, of course; but after enough time has passed and enough evidence has been gathered, they are settled, and science moves on. No camp of scientists is still arguing against quantum mechanics, or the heliocentric solar system, or continental drift. Those disputes have been settled, and science has moved on. (There is still a tiny minority of dissenters to the theory of evolution, but even here the exception proves the rule: these dissenters are motivated first and foremost by religious beliefs.) Today, scientists are arguing about the nature of dark matter, and whether Homo floresiensis is a separate species of human, and what the precise effects of global warming will be on the world's climate. If history is any guide, then doubtless in a few decades these controversies will be settled, and scientists will be considering other new problems.

This progressive process, this building upon past achievements, is the unique hallmark of science as a way of knowing. Unlike religion, science solves problems. Rather than fracturing into perpetually warring sects, science over time becomes more unified, not less, as it steadily increases the number of areas in which consensus has been achieved. This alone should give us confidence that science is actually discovering something real - the true nature of the physical world - as opposed to enshrining the varying products of human imagination.

• Science has built-in methods of self-correction. It can't be overstated that science has a way of overthrowing prevailing wisdom built right in. Everyone is free to submit their evidence and arguments to the review of their peers. There is no central authority who decides what scientists must believe, or what statements may not be questioned. This method has worked well since the scientific revolution, continually updating old and mistaken ideas with new and more accurate descriptions of the way the world works.

When religions undergo correction, by contrast, it is always imposed on them from the outside. Search history for an example of the theologians and authorities of a religious sect being persuaded through rational debate that one of their doctrines was wrong, and then agreeing to change it. I doubt you'll find one. Instead, change in religion occurs when a small group of people declares that the prevailing wisdom is wrong. Inevitably, they are met with ridicule, suppression, and often violence from the established theological authorities. (By contrast, try to find two groups of scientists who went to war over some disputed theory.) Often, this process leads to the factioning of new sects and the beginning of a new round of religious warfare. (See last point.) Sometimes, when society's consensus becomes too overwhelming to ignore, sects' official dogmas do change - although, again, it's usually the authorities who are the last to give way. This dogmatic attitude, unlike the self-correcting humility of science, is far less likely to detect whatever errors there may be in a sect's view of the world.

• Science can demonstrate accomplishment. Even to the uneducated, it should be clear that science works. Through scientific research, we have produced a steady stream of inventions and achievements which people of a few centuries ago - or even a few decades ago - would have considered near-miraculous. In just a few centuries, science has taken the human species from wooden sailing ships to transcontinental flight and space travel; from flint and tinder to nuclear fission; from the four bodily humors to transplant surgery and gene therapy.

By contrast, the accomplishments of religion are non-existent. What advances have come about in two millennia and more of prayer and theology? More potent faith healing? More effective prayers, with a markedly improved response rate? More and better prophets who can do more and better miracles? Forgiveness for sins that could not previously be forgiven? No, religion is in the same place it always was, and is still offering the same explanations for why its beliefs and practices fail to have any measurable, tangible effect on the world around us. If religion had anything like the level of accomplishment of science, people would regularly be flying to Heaven and visiting God in person by now.

If you're seeing this post, then you've made it back! This is Daylight Atheism at its new, and hopefully much faster, host. Thanks for your patience. Regular updates will resume shortly.

I do have a request to make of my readers. Until the move, I hadn't upgraded WordPress since I first set up Daylight Atheism in 2006. I figured, since the move was happening anyway, it was about time I got around to doing that long-overdue software update.

As it turns out, the designers had introduced just enough interesting database incompatibilities in the intervening two years to make that job interesting. Nevertheless, after much grumbling and occasional cursing, I think I've gotten it all sorted out. (No thanks to God, but many thanks to the designers of Perl.) Posts, comments, and all the other data should be here, and commenting and other site functions should be working properly. But to be sure, I'd like to ask you, readers, to be my beta testers. If you have the inclination, please explore the site and kick the tires - check out some old posts, the archives, the search function, and make sure everything is present and working as you expect. If you find anything that's missing, broken, or odd, please drop me an e-mail and let me know. Thanks!

Given the patently unsatisfactory response of my hosting company to the recent slowness issue, I've begun preparations for moving Daylight Atheism to a new host. The DNS transfer will begin soon, and while it's in progress, my domain name may not function for a day or two. If this happens, don't fret. The site will be back up (and hopefully much faster), probably by the end of the week. I'll post updates in this thread for as long as the domain name still works.

Survey time: Has the slowness problem of the past two weeks gone away or are you still experiencing it?

After some back-and-forth, my hosting company claims to have fixed the problem, and it does seem substantially better on my end. Have you all noticed the same?

In "Unmoved Mover", I wrote about the presuppositional argument used by some modern Christian apologists. In this post, I want to say some more about presuppositionalism.

The presuppositionalists have a point in this sense and in this sense only: a worldview is worth being held only if it is possible to reason consistently from that worldview given its own starting principles. If those principles lead inevitably to their own negation, then that worldview is self-contradictory and must be discarded. This is correct as far as it goes. Where presuppositionalists go wrong is in the assertion that Christianity is the only worldview that possesses or could possess this kind of consistency. This assertion is both fantastically arrogant and unequivocally false.

Here's an example of a worldview that genuinely is inconsistent. The laws of thermodynamics say that, over time, entropy increases to a maximum. The higher-entropy configuration - the more "chaotic" state - is always more likely. Yet our universe as we currently observe it is in a low-entropy state, with plenty of organized pools of energy available to do work.

As we proceed toward the future, the overwhelmingly likely outcome is that entropy will increase. But the laws of physics are time-symmetric: they make no distinction between past and future. Therefore, if we look back into the past, it is also far more likely that entropy was higher back then than it is now. Granted, it's unlikely that entropy would spontaneously decrease, from a chaotic past to an orderly present. But if we assume that the past had less entropy than the present, we have an even more unlikely configuration to explain - we're making the problem worse, not better. Applying the laws of thermodynamics in a naive way, then, leads to the conclusion that everything we observe might be a rare, but statistically inevitable, random fluctuation that produces a temporary island of order in the midst of pure chaos.

And the smaller the island of order, the more likely it is that it could arise through random fluctuations in chaos. Thus, compared to the odds of producing an astronomically vast, orderly cosmos, it's much more probable that random fluctuations would produce a single, isolated observer - a disembodied brain, say - floating in the void of chaos and falsely imagining a whole world surrounding it. This is called a Boltzmann brain.

But there's a problem. If we are Boltzmann brains, then nothing we believe about the world can be trusted - including the very observations which led us to suspect we might be Boltzmann brains in the first place. The circle of logical contradiction is closed: observations lead us to infer conclusions which in turn lead us to doubt and disbelieve those observations. The Boltzmann-brain worldview falls apart from its own inconsistency. (This is not to say it's necessarily false - maybe we are Boltzmann brains, there is no way to disprove that - but even if it is true, we could never know it, because the hypothesis itself undercuts all possible basis for believing it.)

The way out of this dilemma is to assume that the evidence is reliable, and that our sensory perceptions and memories of the past reflect a real external world with a real history. This starting point leads to a position which does not contradict itself.

The atheist viewpoint runs along similar lines. Its intrinsic starting point is that the universe is a collection of physical things which exist independently of us, the behavior of which is governed by orderly, immutable principles which we call natural laws. Although the cosmos is complex far exceeding our ability to fully conceptualize it, and although our senses are imperfect and can be misled, we still have the ability to perceive reality with a fair degree of accuracy, to discover its governing principles, and to make inferences about how events will unfold in the future. In other words, we are rational creatures who can learn how the world works.

Contrary to what presuppositionalists claim, this view is consistent. Accepting it as true does not lead to any self-contradiction. (The usual response - that evolution would not produce rational believers - I dealt with in 2006, in "Are Evolved Minds Reliable Truth-Finders?")

Of course, this by itself does not prove that atheism is true. This is a trivial conclusion, since there are infinitely many consistent worldviews, but only one world. A worldview might be entirely consistent with itself and still be false because it does not reflect the way the world actually is. But self-consistency is the starting hurdle that any worldview must clear before we begin examining it to see whether it corresponds to empirical reality. Atheism is one of the consistent worldviews worthy of consideration, and the attempts of religious apologists to rule it out of hand from the beginning - or to make the ridiculous claim that theirs is the only possible consistent worldview - cannot be sustained.