Welcome to Eth, a small planet circling a medium sized star on the far side of this galaxy. It's standing room only in Eth's Great Chamber as the debate of the age is about to take place. Eth's greatest intellectuals are trying finally to settle whether or not God exists.

Garglefroth Blart, Professor Emeritus of Divinity at Eth's most prestigious university, is involved in vigorous debate with his opponent, Bogubus Donk, the Arch Logos Inquisitor. The audience comprises Eth's finest thinkers.

BLART: I'm here to explain why I, and so many other Ethians, believe that God exists.

DONK: What do you mean by 'God', exactly?

BLART: I'm referring, of course, to a being that is all-powerful.

DONK: Ah yes. God, if he exists, is omnipotent. He can do anything. But why suppose such a being exists?

BLART: This universe might not have existed. Why does it exist? Why is there something rather than nothing?

DONK: Well, scientists tell us the universe began with a Big Bang nearly 14 billion years ago. The Big Bang explains that

BLART: But that merely postpones the problem, doesn't it? For why was there a Big Bang? The universe has a cause - the Big Bang. But the Big Bang must in turn have a cause, an explanation. That explanation is God. But God, being a necessary being, does not require cause. So you see: God neatly explains why the universe exists. How do you atheists explain it?

There are ripples of approval from the theists in the audience.

DONK: Well, I'm not sure....

BLART: So you can't explain it. But we theists can. That God exists is the best explanation available for why the universe exists. So there's one good reason to believe. And there are others!

DONK: Such as?

BLART: The fine-tuned nature of the universe. If the laws of nature had been only very slightly different, we wouldn't be here. Indeed, life would not have emerged. The universe would have immediately vanished with a pop, or dissipated into a thin, sterile soup. To get life, you need to really fine-tune your universe. The probability of the universe having the Goldilocks property of being 'just right' for life by chance is astronomically low. But of course, if there's a God that wanted to create living things, then that would neatly explain the universe's fine-tuned character. So again, theism provides the best explanation. How do you atheists explain the fine-tuning?

DONK: Er, well...

There is much murmuring around the Great Chamber. It seems to many that Blart is winning this debate hands down. But Donk has a card up his sleeve...

DONK: Let me ask you a question. God is not just all-powerful is he? He has other attributes too, correct.

BLART: Of course. As we all know, God is all-powerful. And he is also all-evil. His cruelty is beyond our comprehension. His malice is without limit. He is the foulest, most cruel and sadistic being imaginable. He created this universe in order to torture every sentient creature in it.

DONK: But that is absurd. Even if there was some sort of cosmic creator or designer responsible for this universe, it's absurd to suppose that being is all-evil.

BLART: Why do you say that?

DONK: Well, why do you suppose he is evil?

BLART: Clearly there must be such an evil being. You would be foolish to deny it!

DONK: Why so?

BLART: Well, can you imagine God - the most evil being conceivable?

DONK: Well, yes I can conceive of there being such a being, I suppose.

BLART: But this being you conceive of cannot exist only in your imagination, can he, for if he did, then he wouldn't be as awful and terrible as you can imagine him being - as existing in reality, right?

DONK: Well, yes I suppose it's even more evil for him actually to exist.

BLART: So the being you're conceive of must exist in reality as if he did not he wouldn't be as evil as you can conceive of him as being. You see, only a fool, would deny the existence of this evil God!

DONK: Hmm. But look, isn't there a great deal of evidence against the existence of this evil God?

BLART: What evidence?

DONK: Well, there's just too much good in this universe for it be the creation of such a powerful and wicked being.

BLART: For example?

DONK: Some of us act selflessly to help others and reduce suffering, for example. That's a very great good. Why would an evil God allow that? Surely he will want to maximize suffering. He won't allow such kindly, benevolent behaviour. He'll stamp it out!

BLART: That's easily explained, You see, evil God gave us free will. Why? So that we can do evil of our own volition. Evil God could have made us mere puppet beings that always did whatever maximised suffering. But if we're puppet beings, we're not morally responsible for what we do, and so moral evil would not exist. For moral evil - the worst kind of evil - to exist God must cut our strings. He must set us free, so that we can freely choose to do evil! And so he has. Now it's true that some of use choose to do not evil but good. Evil God hates that. But it's the price he has to pay for moral evil to exist!

DONK: Well, what about natural beauty, and naturally occurring goods, such as health and vitality. Even animals enjoy that. That's not caused by us, by our acting freely, is it? So why does evil God create it?

BLART: To maximise evil! Some evils require certain goods. So, for example, Evil God gives us health and vitality, but only as a contrast. He gives us health and vitality briefly and then slowly takes it way - we age, become ugly, incontinent, decrepit, and die painfully! That's so much more cruel than never giving us the wonderful thing in the first place.

DONK: But why does evil God allow love, which is a good thing? An evil God would surely want to eradicate love, yet he gives us children to love who love us unconditionally in return. It makes no sense!

BLART: Evil God hates love. But love is the price he pays for some of the greatest evils. Consider the evil of parents' suffering as they watch helpless as their child dies of disease. If the parent did not love, or care for, their child, then they would not suffer so. Ask a parent what is the worst, most unimaginable pain of all. That pain cannot exist without love!

DINK: But this is...is...ridiculous! You have an answer for everything!

BLART: Not everything. I admit I can't make sense of all the goods there are in the world. But I don't need to. Remember, we are mere humans. For all we know there are reasons why an evil God would allow the goods we see, reasons that are beyond our ken. Just because we can't think of such reasons does not mean they don't exist, does it?

DONK: Well, no I suppose not.

BLART: So there you are! For all you know, there is an evil-God-justifying reason for every last good we see in the world. For all you can tell, this really is the worst of all possible worlds! But then your so-called 'evidence' against my evil God vanishes!

The discussion comes to an end and hush settles over the Chamber as the audience decide their verdict. Eventually, a spokeswoman stands to reveal the result.

SPOKESWOMAN: We have decided. Professor Blart has established that the existence of evil God beyond reasonable doubt. Evil God provides the best explanation for the existence of the universe and also its fine tuned character. He has provided an argument for God's evil character. And he has successfully dealt with all of Arch Logos Inquisitor Donk's objections. The motion is carried. Evil God exists.

Of course, not withstanding all of Blart's ingenious arguments and explanations, we can know that belief in an evil God is downright ridiculous. We can know that just by looking at the kind of universe we inhabit. And if we can know that, then why can't we know that belief in a good God is no less ridiculous?

Actually, we can.