IDEA has one answer. I have other ideas.
Question by the Intelligent Design and Evolution Awareness Center (the IDEA Center):
Does intelligent design make predictions? Is it testable?
Answer according to the IDEA Center:
“Intelligent design theory predicts:
1) that we will find specified complexity in biology. One special easily detectable form of specified complexity is irreducible complexity. We can test design by trying to reverse engineer biological structures to determine if there is an “irreducible core.” Intelligent design also makes other predictions, such as
2) rapid appearance of complexity in the fossil record,
3) re-usage of similar parts in different organisms, and
4) function for biological structures.
Each of these predictions may be tested–and have been confirmed through testing!”
Yes and no, but the no is bigger.
The IDEA Center is a student-targeted initiative co-founded by Casey Luskin, now of the Discovery Institute. It encourages high school and tertiary students to set up their own IDEA clubs and talk about intelligent design. I use the present tense because it’s never officially folded, but there has been no visible activity by IDEA since a screening of The Privileged Planet in 2007.
I’m not simply flogging a dead horse (with regard to IDEA and intelligent design itself) because the question applies to the now more openly advocated hypothesis of divine design. It concerns a major aspect of claims by any creationist group that their version qualifies as science: is it falsifiable? What does it tell us that we don’t already know? What would disprove it?
I’ll work through the points in IDEA’s answer.
1) Two kinds of “specified complexity” crop up in creationist arguments: irreducible complexity, and “complex specified information” such as that found in DNA.
The discovery of irreducible complexity in a lifeform might go a long way toward proving design, though this hasn’t happened so far. Every purported example of irreducible complexity has been hypothetically reduced, in other words a possible evolutionary pathway to its current state has been found. On the other hand, the absence of real examples doesn’t mean nothing is designed. Irreducible complexity is only useful to this issue at all if it’s actually found.
The term “complex specified information” subtly begs the question, implying that someone specified it. While there’s certainly complex information in DNA, this is predicted and indeed required by evolutionary theory as well. The instructions for building body parts, the essential products of mutation and natural selection, have to be stored somewhere.
There’s a larger example of begging the question here. Of course the design hypothesis will predict the very thing it was created to explain: the complexity of life, including its means of reproduction and information storage. The important predictions we get from science are those with new, as yet unknown information – those we have to go out and test, not just refer to the same information that spawned the hypothesis.
For instance, we have one less chromosome pair than our closest ape relatives. Losing a pair outright is catastrophic, so the only way our species could have arisen from apes with one less chromosome pair is if two pairs fused. Therefore the end-markers for chromosomes should appear in the middle of just one of our pairs. On investigation, they showed up in pair #2. If they hadn’t, or had appeared in more than one pair, evolutionary theory as it exists now would have been falsified.
2) Again, the rapid appearance of complexity is a non-unique and retrospective prediction by the design hypothesis. Evolutionary theory allows for it as well, for a given value of “rapid”.
The most famous example is the “Cambrian explosion”, which took not less than two million of the fifteen million years now known as the Cambrian period. That’s as long as homo habilis took to evolve through homo erectus into us, homo sapiens. Given that it’s also roughly the point where the animal kingdom itself began, one would expect tremendous diversification.
A prediction certain design proponents might make which is not shared by evolutionary theory is not the rapid appearance but the literally instantaneous appearance of complexity. Like irreducible complexity, this would be earthshaking if found, but until then its apparent absence tells us nothing.
3) Similar features in creatures which are not at all closely related is another thing evolutionary theory also predicts in unremarkable hindsight, via convergent evolution. For example, across the animal kingdom we see eyes at all stages of development because eyes are undeniably useful. Any creature which begins to develop sight has an immediate advantage over the blind.
4) “Function for biological structures” mostly refers to DNA, and the idea that it’s all useful. The existence of “junk DNA”, that which has no effect on the creature which carries it, does not obviously indicate a design purpose, so the prediction of design is that practical effects will eventually be traced to most or all of it.
Given that we don’t know the purpose of a lot of DNA, new purposes will surely be found for some of it, but what’s the failure standard here? What percentage of DNA, if confirmed to be absolutely useless, would disprove design? There’s no sensible answer. Design isn’t falsifiable this way either.
In the broad view, we have 1. a bunch of different ways evolution could at any moment be debunked or disproved (and, notably, hasn’t been) and 2. no good way divine design could ever have potentially been disproved. It makes obvious predictions, all right, but it can’t truly be tested. Hopefully I’ve managed to demonstrate the difference a little more for you.
10% of the proceeds from the show will go towards stem cell research, which is a great thing, but they’re pretty sure it’s hurt their publicity campaign.
We got a request to publicise a month-long exhibition in California named, and themed, Scientific Evolution.
10% of the proceeds from the show will go towards stem cell research, which is a great thing, but they’re pretty sure it’s hurt their publicity campaign.
I’ve done as they asked for two reasons. One, any publicity for evolution itself is good when the principal weapon against its acceptance is ignorance. Two, it’s very probable that the negative publicity for this art stems directly from conservative religious groups, and (imagine Marvin the Martian’s voice) this makes me very angry.
If you’re in California, see whether the exhibition would interest you. If not, have a look round for any protestation against it. I wonder if we can identify particular antagonists?
While Pascal’s own Pensees is more in-depth, this is the basic version presented by most evangelists: If God exists and you live as if He does, your reward is infinite. If God does not exist and you live as if He does, you lose nothing. If God does not exist and you live as if He doesn’t, you gain nothing. If God exists and you live as if He doesn’t, your punishment is infinite. Therefore if there is the slightest chance that God exists, by any analysis of benefit it is better to live as if He does, in other words believe in and worship Him.
The same argument is often expressed in shorter form: “What if you’re wrong?”
This is an argument I’ve been answering constantly ever since I started on the original ATA. No matter how many times it comes up, there are always those who think it’s a brand new, ingenious zinger which will take us by surprise. I’ll refer back to here in future.
There are five main issues with the Wager, any one of which would render it nonsensical or inadequate.
1. It presents a false dilemma: that either God exists or no god does.
There is an obvious third option, namely that any deity besides the expected god exists. If the real deity is Thor, for example, the punishment for Christians is infinite (possibly worse than for atheists, who at least do not worship a rival god).
Humans have imagined something like 20,000 different major deities or equivalents so far. Together with the countless ones we haven’t thought of yet, there are an infinite number of possible gods. Without evidence for any particular god, all gods share equal probability of practically zero, and the probability of a particular god existing is infinitesimal compared to the probability of one or more rival gods, so worshipping any god is a hugely bad bet.
The response to this, I know, is to argue that there is evidence for your particular god and not for any of the others. That’s a valid response, if true. However, if you have proof positive that your god is the one and only there’s no need to mess around with probabilities, so you don’t need to use Pascal’s Wager in the first place. Just push your evidence instead.
2. If there are no gods, you don’t lose nothing by living as if there is one. You lose plenty.
You spend hundreds or thousands of hours attending religious services. You give money to organisations whose primary purpose is not to help people but to convert them. You prevent yourself from doing some things you enjoy, not because they hurt anyone but because a book told you to. And so on.
3. Belief in gods is not a choice.
A person either believes there’s a god or doesn’t. This may change, but it’s not a conscious decision by the person. Her or she has to be convinced, or else no longer convinced, one way or the other. The idea that it’s beneficial to believe in a god does not support the idea that there is one. They’re two independent issues.
4. Any decent god would spot a faker.
This is related to the third point. If an atheist were convinced that it’s beneficial to believe in and worship God, he or she could certainly worship, but would still not believe. The worship would therefore be insincere on a fundamental level. It’d be a farce, maintained to give the appearance of belief. Would the Christian god, for example, accept this lip service?
It’s said by some religious folks that if you pray with doubt, but pray with sincerity, belief will come. I don’t doubt it; if you pray as if there’s a god there for long enough, you may manage to forget that there isn’t. If brainwashing yourself like this is the only way to believe, however, are you really doing the right thing?
5. Is belief really the key?
What if one specific god does exist, but the important thing is not that one believes in Him/Her? Counter to the evangelist perspective, but what if works trump grace/faith/being “saved” in terms of brownie points in the real Heaven?
In short, Pascal’s Wager uses an incomplete and incorrect premise, and is useless to nonbelievers even if they agree with it. Blaise Pascal himself supports it in the Pensees by arguing separately for the existence of the specific Christian god from several angles, which is exactly the response to issue 1 I’ve described which makes the Wager redundant. By itself, it’s just pointless.
“…false dilemma: either the authors took wild guesses and were correct multiple times purely by chance, or they were divinely inspired and therefore granted knowledge the rest of humanity didn’t have at the time.”
The basic form of this argument is that the Bible or some other holy text predicted some event or phenomenon its author(s) could not possibly have known about without divine inspiration. Examples: Jesus’ life and death fulfilled hundreds of prophecies made about him in the Old Testament, every detail of the 9/11 World Trade Centre attack was laid out in Revelations, the Bible or Quran describes scientific facts only discovered later by scientists themselves.
Claimed predictions by the Bible (from which my examples will be drawn, since they’re what I’ve mostly received) and other old texts are presented along with a false dilemma: either the authors took wild guesses and were correct multiple times purely by chance, or they were divinely inspired and therefore granted knowledge the rest of humanity didn’t have at the time. There are a number of other possibilities for each supposed prophecy or prediction, which are generally more likely than either. The names below aren’t universal, they’re my own.
1. High Probability of Success: the event predicted was likely almost to the point of certainty, especially given unlimited time in which to occur.
In Jeremiah 49:16, the fall of the city of Edom was prophesied. Edom had many enemies, including Israel, and was regularly at war. Which was more likely, that it would triumph forever or that at some stage it would be destroyed?
2. Still Unknown: the fact given by the text is in dispute even today.
Christians credit the Bible with foreknowledge of cosmology for saying that the universe had a beginning. Even if this is correct, it had a one in two chance which is hardly imposing odds. Importantly, though, the Big Bang might be the very beginning or it may have been caused by some precursor. There’s still the possibility of an eternally old universe or multiverse. Claiming credit for predicting a beginning at this point is like trying to collect your winnings from a horse race before it’s ended.
3. Self-Fulfilling Prophecy: the very existence of the prophecy assists in its fulfilment.
There were prophecies, at least as told in Jeremiah and Ezekiel, that the captive Jews would return to their homeland of Israel. Assuming for now that the non-supernatural parts of the stories are true to begin with, the Jews themselves knew of this prophecy. They believed God had stated directly that they would return. To do so was to obey His will. No wonder they did everything they could to get back.
In a more general sense, the Bible lays out a complete future history of Israel and Jerusalem. The Jews there do everything in their power to follow the instructions as far as rebuilding and protecting it, and largely use the actions of the Muslims to fill in the bits about invasion, destruction and exile.
4. Shoehorned: the text only applies to reality or to the present day through an unwarranted act of lateral interpretation.
Isaiah 40:22 says, “It is He that sits upon the circle of the earth.” Some take this as a signal that the author knew ahead of everyone else that the Earth is a sphere, when the word “circle” seems more likely to refer to the apparent disc one sees when one looks out from atop a mountain. The now-all-but-defunct Flat Earth Society, which believed the statement as much as any other Christian group, maintained their position of a flat Earth because they interpreted it as I do.
5. Made to Order: accounts of a subsequent event were in fact tailored to fit the prophecy.
This possibility is most often applicable to the story of Jesus. The authors of the Gospels had access to the writings of Isaiah et al, and had every opportunity to make sure their own accounts lined up with the old prophecies. Jesus, after all, would have been just one of an army of self-proclaimed Messiahs at the time. He needed everything possible to make him stand out, and that meant fitting the bill to the letter.
This list is not a direct accusation that any of the above is in fact the case for any given prediction in an ancient text (extending beyond religion, to writers like Nostradamus). However, any given prediction in texts I’ve read can be explained by one or several of the above. These extra possibilities must therefore be considered in addition to the false dilemma of chance or God. In this company, divine inspiration is less of a sure thing to say the least.
So what kind of a prediction would bypass all of the above and appear truly, plainly supernatural in its accuracy? Simple: one that we are able to test ourselves, without any prior knowledge. An obvious example is the Rapture: if it happens, those of us who are left will know that prediction was right. You can’t engineer the Rapture, or interpret the bodily disapparation of every Christian (of only one denomination, you would assume) any other way.
For a less extreme example, say that instead of interpreting dates gone by to match counts of days in the Bible, someone uses Revelations to predict the day of a future earthquake in Los Angeles, far in advance of seismologists. It could still be coincidence, but it couldn’t be Shoehorned or Made to Order. Further, the chances are low, the outcome is known and the prophet couldn’t fulfil it him/herself without a nuclear weapon.
That, therefore, is what believers in Biblical prophecy need to do in order to score credibility: use the old texts to make new and accurate predictions, instead of cultivating awe for those gone by. Many do try this, of course, and so there’s a growing list of dates for the Rapture, the Tribulation, the Second Coming and lesser events like the collapse of the United States. So far, all of these dates have passed by uneventfully.
“…theists may claim that anything natural with any quality to it whatsoever must have been deliberately crafted with humanity in mind.”
Here’s a sample of the many different ways in which the same basic question is posed: How did all the beauty around us come to be? How did intelligent people come from monkeys, or oranges, or sludge, or nothing at all? How did life begin if the chances of the necessary proteins assembling was one in ten to the power of hundreds? (The next one’s taken from an actual wall poster:) How can anyone witness a sunset and not believe in God? Why is there any order to the universe? Why are the fundamental constants of the universe tuned so that matter, and humans, can exist at all? How is it that we live, and live in such a wonderful world, if it all came about by chance?
From the development of the eye to the beauty of a waterfall to the exact value of the gravitational constant, theists may claim that anything natural with any quality to it whatsoever must have been deliberately crafted with humanity in mind. This is the Argument from Design.
Even if it were correct, it’s a terribly egotistical way of looking at the world. And even if it were proven to be correct, no religion would have any basis upon which to claim that the designer or creator was its particular god or gods.
The basic answer to the argument from design is that there is no substantive evidence for it and therefore 1. to assume design in the presence of alternative theories supported by substantive evidence is putting one’s head in the sand and 2. to assume design even in the complete absence of alternative theories is an argument from ignorance.
Beginning with evolution and the development of intelligent humans, there is a huge amount of geological, genetic and observed evidence to support the currently held view of the “tree of life”. Evolution of subspecies is observed all the time, and contrary to a common objection whole new species have been seen to emerge, and recently. (This article on speciation has some examples.)
Contrary to another creationist talking point, there are tons of known transitional fossils. Contrary to Kirk Cameron, these don’t look like half of one animal joined to half of another (like his famous Croco-duck). They’re more like what you get if you morph a whole picture of one into a picture of the other, but stop halfway.
To dismiss evolution as a useless series of random changes is an argument from personal incredulity, which is a type of argument from ignorance. It’s also wrong. The mutations are random, but only the beneficial mutations tend to be passed on by sheer survival and procreation skills. Evolution doesn’t just try random things and get it right every time, it tries everything and goes with what works. It’s like trying to hit a dartboard by spraying the whole wall with a machine gun. You’ll miss a lot, but you’ll hit it too.
Intelligence came about because at every stage in the development of primates, the ones who are just that little bit smarter than everyone else will always have the advantage. Over millions of years, it all adds up. Along with this comes morality (since good deeds are often rewarded), an appreciation of beauty (since it helps if what’s pleasing to the eye is usually not diseased, poisonous or dirty) and emotions (to motivate us to do what’s helpful to us and others).
Going back to the origin of life, abiogenesis as it was called could have occurred by a number of different chemical processes. So far scientists have used electricity (lightning) and a replica of the ancient atmosphere to create amino acids, which are pretty close. With a whole world full of chemicals being blown and washed into each other and billions of years to work, there was ample time and material for the components of the first replicating organism to slowly accumulate. The huge odds against this often given by folks like Hoyle generally assume firstly that they all had to come together at once, and secondly that only one version of it could possibly work. Once one little bit of DNA was off and running, evolution and exponential growth took over.
Before we tackle the whole universe at once, let’s consider Earth. Someone might claim that God put Earth exactly where it needed to be relative to the Sun so that liquid water and therefore life could form. We now know, however, that there are a lot more planets out there, and probably huge numbers of undiscovered ones. It’s not that Earth was placed where liquid water could form. Rather, liquid water only forms on planets of the right temperature and Earth happened to fit the bill. Lots more planets might. This is called the anthropic principle: places aren’t made for humans, humans just have a chance of turning up in hospitable places. Even on Earth there are many places we can’t survive, like inside volcanoes and kilometres under the sea. So, we didn’t emerge from there. Big surprise.
The largest design claim has to do with the fundamental constants of the universe. Six major ones are usually mentioned: those pertaining to gravity, electromagnetism, spatial dimensions and other less famous concepts. As is repeated endlessly, the slightest difference in any of them might result in matter being unable to form or stay together. This is the “fine-tuned universe” argument.
The problem is that even if this is true, there could still be other values of the constants which support matter. Perhaps instead of changing one or two slightly, you need to shift four of them by a huge amount. Considering that some of the constants could even be negative, you’ve got an infinite six-dimensional sample space in which to test hypothetical universes. We may never know whether our values are the only valid ones. Or, we may stumble upon another valid combination and that’ll be the end of this argument.
Besides, the anthropic principle applies again if you consider the theory of a multiverse. If there are multiple (perhaps infinite) universes each with its own set of constants, of course we’re going to turn up in the universe with a friendly combination. Other life forms may be thriving in universes where we wouldn’t last for a second, and understanding how would require us to re-learn physics from scratch.
Contesting the argument from design is hard work, because to be most effective you need to know the going theories for whatever phenomenon is in question. I’ve tackled the most common ones, but be prepared for just about anything useful or pretty to be presented as direct evidence for gods. Then you need only find out where it really came from.
“My aim is make this a reference for any subsequent “origin” questions.”
This is the Cosmological Argument for the existence of God, in the form of the popular Kalam Cosmological Argument:
1. Whatever begins to exist has a cause.
2. The universe began to exist.
3. Therefore, the universe had a cause.
Following on from that, the cause of the universe must have been eternal and therefore without cause. Besides being eternal, this Uncaused Cause must have been all-powerful and all-knowing, as it literally created everything else. It must be God.
My aim is make this a reference for any subsequent “origin” questions.
The Cosmological Argument or Argument from First Cause is the proper form of the common argument that the universe must have been deliberately created, and you can’t get “something from nothing”. It predates Christianity, as Plato and Aristotle had their own versions.
That’s the first issue with the argument: it only attempts to prove the existence of a Creator. It is therefore a deist argument, so when a theist uses it to prove a specific god with no further logic it’s a step too far. Keep an eye out for this.
The basic premise that everything finite requires a cause is the least controversial part, but even this isn’t rock solid. Possible exceptions are found in quantum mechanics, where particles move about in a probabilistic fashion. Until observed, a particle may be anywhere in a small area, and in a sense is everywhere in the area. When you observe it, it picks one spot and stays there. This is of course a gross oversimplification, but the point is that there’s no known force moving the particles around. There may actually be no cause as such, and the universe may be far more spontaneous than we think.
Even “something from nothing” is plausible according to a related theory that “nothing” is really a quantum foam from which matter may emerge. This is purely theoretical at the moment (it makes mathematical sense, but there’s not much physical evidence), but it’s worth remembering that science is actually considering ways like this in which matter could just pop out of “nothing”. It can’t be dismissed entirely.
Causality may also be irrelevant if time wasn’t linear at the beginning, if it had a beginning. An effect must follow its cause, but this is meaningless if chronological order hasn’t settled down yet.
The universe is widely regarded by lay people (who aren’t young-earth creationists) to have begun with the Big Bang. This may seem counterintuitive – how can something be created by an explosion instead of destroyed? – but it was no ordinary explosion. All the matter and energy in the universe was compressed into a singularity, a point so small it had no volume at all. (Absurd as this sounds, it happens today with large amounts of matter in the centres of black holes.) Then it expanded outwards, and it’s still expanding to this day. Once the matter was in that singularity, nothing was created or destroyed, only distrubuted.
How did the matter get in there? Was the Big Bang the true beginning, or a continuation of something else? We haven’t a clue. A god is one hypothesis. Other universes, with their own separate systems of time and space, are another. The quantum foam is an outside chance. Who knows what else we haven’t thought of.
I like the idea of a multiverse, an eternal group or series of universes setting each other off. It’s got one up on gods because it’s multiple instances of a known object. We know there’s at least one universe (this one), while we don’t have a single example of an established god. If you see a huge cabbage patch where the whole crop’s been eaten, and you find one fat little rabbit in the corner, do you assume that Bigfoot must have done most of the damage? No, you wonder where all the other rabbits are hiding.
The theory of expansion and contraction, of many Big Bangs and Big Crunches, has fallen apart recently with the discovery that the expansion of the universe is apparently accelerating. That means it will never return to the singularity, and it is not cyclical in the way we thought. That doesn’t stop it from being cyclical in other ways, for example stretching until it tears a hole and then draining out to somewhere else.
The point is that if you do accept that everything finite must have a cause, something must be eternal. Either it’s the universe/multiverse, or it’s a god. There are many theories, and potentially many more, which allow for an eternal universe which needs no cause. Therefore an eternal god is not the only option, and anything which says so is a poor attempted proof of its existence.
Note: The argument that a god created the universe based on the universe’s nature, order, awesomeness, etc. is not related to causality. It’s the Argument from Design, which is next on the GBA hitlist.
The Ontological Argument: “…the equivalent of trying to win a lawsuit on a technicality.”
There are many forms of the Ontological Argument for the existence of God. The following is Wikipedia’s optimal modern description.
1. God is that entity than which nothing can be greater.
2. The concept of God exists in human understanding.
3. God exists in one’s mind but not in reality.
4. The concept of God’s existence is understood in one’s mind.
5. If God existed in reality, it would be a greater thing than God’s existence in the mind.
6. The final step to God’s existence is that God in reality must exist.
The Ontological Argument strikes me as the equivalent of trying to win a lawsuit on a technicality. It’s a full-blown a priori attempted proof which assumes only that a perfect being is conceivable. I won’t argue this point, because although definitions may differ everyone gets some image in mind upon hearing the phrase “perfect being”.
The thrust of the argument is that it’s greater and more perfect to exist than not to exist. Since God in theory is the greatest and most perfect thing ever, He must exist.
The most obvious problem is that the argument is not the least bit specific about which God exists. Even if the argument were unassailable and the existence of a god were proven, we would still know absolutely nothing about the god’s identity or nature. Jumping immediately from the existence of a god to the existence of your god is an unsupported assertion.
If you really wanted to be annoying, you could argue that since the argument can be used to prove the existence of multiple mutually exclusive gods (say, the God of Abraham and Ahura Mazda of the Zoroastrian faith) it’s obviously a flawed argument. The theist reply is of course the above point that the argument makes no comment on the god’s identity and most religions just have the wrong guy, but it’s a good way to make people think.
The real problem is the premise that to exist in reality is greater and/or more perfect than to exist only in the mind. Something which doesn’t exist isn’t more perfect than something which does, but it isn’t less perfect either. It has no qualities by which this can be judged. An apple which doesn’t exist isn’t red, but neither is it purple. Therefore it can’t be redder or less red than a real red apple.
Existence isn’t a property as such either. Even if it were, it wouldn’t necessarily be a positive property, or something a perfect being must have. Something destructive like an earthquake might be better if it didn’t exist.
There are plenty of objections along these lines by a great many people, the most famous being Bertrand Russell and Immanuel Kant. As stated in the question, there are also a great many rephrasings of the argument which try to circumvent these objections.
The net result is that major apologetic organisations have advised that the Ontological Argument in its current forms does not stand up to scrutiny, and other arguments like the Transcendental and Cosmological Arguments (the favourites) should be used instead.
That doesn’t stop a lot of YouTubers from reciting obscure forms of the Ontological Argument and expecting them to be invincible. Look it up, and enjoy the logical knots both sides get themselves into when discussing it.
I always worry when someone uses this argument, because it may mean a few things. Maybe they don’t think people have the intelligence to fully comprehend such a complex-sounding argument and will accept it by default. Maybe they haven’t read the objections and don’t expect anyone to look them up. From a big-picture perspective, they’re using a less well known argument thinking it will take people by surprise, not considering that it’s less well known for a reason. It just plain doesn’t work.
The Transcendental Argument: “…the equivalent of winning at chess by knocking over all the pieces.”
I’m quoting an admittedly simplified version of this argument by the Christian Apologetics and Research Ministry (CARM). Read the original here.
“Logical absolutes exist. Logical absolutes are conceptual by nature, are not dependent on the space, time, physical properties, or human nature. They are not the product of the physical universe (space, time, matter) because if the physical universe were to disappear, logical absolutes would still be true. Logical Absolutes are not the product of human minds because human minds are different, not absolute. But, since logical absolutes are always true everywhere and not dependent upon human minds, it must be an absolute transcendent mind is authoring them. This mind is called God.” Follow the link for CARM’s own list of possible objections and responses to each.
The Transcendental Argument for the existence of God (TAG for short) demands a certain sardonic respect due to its sheer ambition. In its full form, it claims that logic (and by extension rationality, sense, morality and any argumentation at all) can only exist if the Christian God does.
In simplified form it’s not Christian-specific, but it can be used at any point in an argument to override the whole thing and declare that the argument is only possible (or evidence is only understandable as a concept, or our senses are only reliable) if there’s a god, so one must exist.
This approach does not convince many atheists as far as we know. It seems like the equivalent of winning at chess by knocking over all the pieces. Nevertheless it’s difficult to find a clear hole in it which Christians in particular haven’t already closed with an addendum (see how much longer CARM’s list of defenses is than the argument itself).
One good way to make it a lot less convincing, strangely, is to temporarily presuppose the existence of God. If God exists, He still isn’t guaranteed to be the source of logic, because how could we check? We couldn’t go to a universe without God to see whether logic fails there, either because we’re stuck in this universe or because God’s omnipresence extends beyond it. In other words, if God’s there we can’t remove Him to see whether logic is independent of Him.
Therefore even if God existed and we all knew it, that logic is dependent on Him could only ever be an assertion and the Transcendental Argument is still not self-evident. If He doesn’t exist, of course, then the TAG is not only moot but flat out false.
I have two other major objections which CARM’s pre-emptive defenses don’t fully cover. Firstly, logical absolutes, rather than being conventions, eternal or anything else CARM mentions, may not really exist at all but instead may only be apparent.
Secondly, if logical absolutes do exist, saying that they must be the product of an absolute transcendent mind is an argument from ignorance. (Likewise is the assertion that if the physical universe were to disappear they would still be true. Again, how would you check?) Even if they’re not the product of the physical universe or human minds, there may be any number of unknown alternatives besides a transcendent mind, or any mind at all.
I realise that most objections to the TAG are simply alternative hypotheses and doubts as to its basic assertions, but that’s really all you need. If there is any possible alternative, an argument presented as the only possible state of affairs cannot be a proof until it clearly dismisses all competition. Once the possibility of an a priori proof is gone, the TAG loses its power and becomes just another thing theists say.