First off, what is Woo? For our purposes it's going to include just about any example of pseudoscience or superstition that you can think of, like homeopathy, anti-vaccination, and religious claims. Because most of these groups basically use the exact same arguments in support of their brand of woo, the term should be interchangeable.
The purpose of this blog post is to educate the reader on quick and efficient ways to refute common woo claims. While you probably have some experience in defending your beliefs (or more properly, lack thereof) there are still occasions where opponents will catch you off guard. Maybe it's your first time hearing the argument, or maybe you don't quite know how to properly respond. In either case, it's my hope that after reading this you'll be better prepared to go up against defenders of woo. Before the specific claims are addressed, however, there are some basic precautions that apply in all cases.
First, there are two main mediums where these debates will take place: in person and online. When you are encountering a person face to face, you should always be the more level-headed one. It can be tough to hold in your emotions, especially if you feel you're getting nowhere with the other person or they've touched a nerve. However, no one has ever been deconverted by being yelled at and called stupid. Phil Plait outlines that principle in a great talk here. When online, the same protocol of calmness applies. It's far too easy to forget that the emotionless profile picture of the wooer (person who believes in woo) is an actual person. If you wouldn't say it to their face in that way, you shouldn't say it online. Certainly a level of sarcasm and mockery may be appropriate, so long as it's to the belief rather than believer. Another necessity of online debating is that spelling and grammar matter. Ur n0t gunna B takn srsly if ur ritn in internetz speek LULZ :DDDDDD.!!!!!1!!
Secondly, you should have a thorough understanding of logical fallacies. Though I will specifically list exactly what fallacy is occurring in the Wooer's argument, this knowledge serves a broader purpose of being an "ace in your sleeve" for just about any confrontation, woo related or not.
Thirdly, ask the wooer for their best argument in support of the woo. If you can beat the best claim, then logically there is no reason to examine any more, except to beat a dead horse for the hell of it. Part of this includes forcing your opponent to admit when they are wrong on a specific point. Do not let them change the subject. Until they have said the claim is invalid, the issue is not settled, and should continue to be addressed until it is. The same applies to you if it's obvious that you've been bested.
Finally, it's important to remember that the side with the best, not necessarily the most, empirical data will always be the stronger side. The more independent research you do by yourself, especially concerning the reasons behind pro-Woo claims, the better off you will be.
Now for the actual substance. While these will certainly not be all the pro-woo arguments you will hear, they are (by my experience at least) the most commonly used by the average wooer.
1) You can't prove that woo isn't true.
This is certainly not the case all the time, but it is also not your responsibility to do so. What the wooer has just tried to do is shift the burden of proof onto you. However, you are not the one making the positive claim. By this, I mean the person proposing that something is true has the burden of proof to show that it is.
However, if you do make a positive claim (ex: there is no god, or homeopathy does not work) then you have to provide evidence for your proposition. In the case of pseudoscience woo, this can be pretty easy. Homeopathy, for instance, has been shown to be equivalent with a placebo in regards to its medicinal value, since it's just water. For these, you just need better scientific data from as many unbiased sources as possible. However, for religious claims it is much harder to show negative evidence, so it is advisable to simply debunk the positive claims of the wooer. As Christopher Hitchens is famous for saying: "that which can be asserted without evidence, can be dismissed without evidence." If there is no evidence for the deity, then there is no reason to even humor the thought of it possibly existing. If they don't accept this as a valid reason, make up something on the spot and ask them if they believe in it. When they say "no" and inevitably "because there's no proof for it" you've got them.
2) Dr. Pro-woo of Prestigous University with a BA, MA, and Ph.D says woo is true in his new best selling book
This is known as an argument from authority, and often is also an argument from false authority. While university degree's can add to the credibility of the person, the fact that just because they said it does not make the woo true. Rather, the woo itself has to be addressed. Even in the case of skepticism, if we were to cite something being true just because someone like Richard Dawkins or Phil Plait said it was, we would be committing the same fallacy. Rather, we also look at the claim itself, such as evolution, and the mountains of evidence that support it. If it isn't backed up by empirical data, it doesn't matter who is supporting the woo. It's still wrong.
It's also important to remember that while pointing out that a speaker may have no business talking about a particular subject because it's one they have no knowledge on (for example, Victoria Jackson on the subject of TV depictions of homosexuality), that says nothing to the validity of the claim they are making. To assert this is to commit both a circumstantial ad hominem, and the straw man fallacy. It is always the claim that must be addressed, not the person making it.
3) As it says in the Book of Woo...
A holy book saying to believe in a woo doesn't mean you should. For the same reason as above, if there isn't any evidence to support the claim then it can be dismissed. This is a different case from Dr. Pro-woo because the authenticity of religious texts are often held in higher regard than earthly experts, and usually blindly as well. If they're going to cite a holy book, then both the claims and authenticity of it need to be looked at. Most religious texts make their own extraordinary claims, and as it's often said, those require extraordinary evidence.
So first off, what makes that particular holy book more legitimate than all the others? Holy texts begin with the assumption that what they are saying is true, and occasionally bastardize skepticism, preferring faith to proof. Usually it's postulating the existence of a deity, and that deity is also usually the one saying the book is true. This is known as circular reasoning, or begging the question, in that the conclusion is supported by the premise because the conclusion is true. Since most religous texts fall prey to this, we are still no closer to the validity of the particular book, and thereby the particular claim in question.
In some cases, archeological evidence is provided to show the texts validity. However, that says nothing to support the supernatural claims of the book anymore than the Harry Potter series citing the very real location of Kings Cross Station in London provides evidence for Hogwarts.
Sometimes it's claimed that because there are a lot of followers of that books woo that makes it true. This is also fallacious as it's an appeal to popularity. What one is usually able to see is that this is purely circumstantial, given either the woo's past of evangelism or cultural geography.
Many of these books also make prophecies, and sometimes members use the 'fulfillment of prophecy' as proof for it's validity. After all, if the it knew X event would happen, then it must be true, right? Well, no. A lot of people have made numerous prophecies throughout history, like Nostradamus and every astrologer that's ever lived. What really needs to be examined is not how often they are interpreted (yes, interpreted) to be right, but how often they get it wrong. Most people disregard the 'misses', but remember the 'hits' when it comes to prophecies. That's how cold reading works. Furthermore, most are very poorly interpreted from purposefully vague language so that the reader is able to apply the prophetic statement to just about anything.
The last claim I'll list, though it certainly isn't the last, is that the level of sacrifice made by believers of the woo on its behalf means that it's true. However, killing yourself or others for any belief does not make it more valid than one where it's believers do not. If this were the case, the 9/11 terrorists, Charles Manson cult, and 1978 Jonestown Massacre victims did a number to validate their religious beliefs.
Scientific books like On the Origin of Species by Charles Darwin, on the other hand, can be taken as legitimate as a case is built from the ground up (again, using evidence) which can be scrutinized under peer review. What's more, science is not dogmatic, so when it gets something wrong it comes out and says it, and does what it can to correct the error. We are also not just postulating that the book of woo is wrong because it's old. George Washington's writings are also old, but we don't dispute that he existed. Why? In large part because supernatural claims were not made about George Washington by others or himself, and any myths surrounding him have been debunked.
4) I had a personal experience with woo and it changed my life
You can't do much to make a person doubt their own personal experience, though there are several examples where you can show that it probably didn't happen. If a person's life is changed in a positive way (or at least they say it is) because of the woo, there's no disputing that. All you can really address is the validity of the experience itself.
In some cases of woo, the phenomenon of pareidolia can occur, where we see faces or special significance in everyday things, like cheetos and grilled cheese sandwiches. This phenomenon is also how we distinguish actual faces, which is a very useful survival tool, but has an unintended consequence of also interpreting things with face-like or human-like qualities to be actual faces or humans, respectively. This could account for woo experiences like ghosts, religious visions, bigfoot, aliens and a plethora of other things.
Some claim to feelings of euphoria from their experience. This can be attributed to the placebo effect, where something that has absolutely no ability to cause any physiological changes within a person does so on a purely psychological level. It is a well documented phenomenon, and as such is the standard in medical practices to determine if a proposed medicine has any real effects or not. But such feelings don't just occur after taking a sugar pill. Literally anything could potentially cause this effect if the person receiving the 'treatment' believes so hard that their body will, by itself, produce the effects.
Finally, there is confirmation bias. This occurs when we want something to be true so badly that we will make the jump in believing that because X happened it was caused by the woo. In the anti-vaccination movement, this is exemplified when someone claims that they haven't been vaccinated but also haven't caught the disease, so the vaccination is fraudulent. In reality, they are more likely being protected by herd immunity from the people who have been vaccinated for the disease. Illnesses that had previously been eradicated, such as polio, are starting to come back as a result of the vaccination scare.
It happens all the time in religion when everything from finding ones car keys to surviving an emergency situation are attributed to the deity in question rather than ones ability to remember or the trained hands of professionals. This has lead to a rise in faith healings, such as exorcisms, which prevents many people from getting the medical treatment they desperately need.
5) If you don't believe in woo, bad things are going to happen to you
This is a blatant threat. At this point you would be fully justified in ending the conversation right there. This is usually a last resort, be it damnation or jeer that you're contributing to a global conspiracy, when the wooer has nothing more to add to the conversation and thinks they can scare you into seeing things their way. However, you can still argue against this if you feel like it. Again, evidence is key. If you've debased all of their beliefs in any of the above categories, they basically have no foundation to stand on to claim that this is valid. In religious cases, this is known as Pascal's Wager, a philosophical thought experiment concluding that one should believe in the Judeo-Christian Jehovah to reap the benefits of Heaven rather than possibly risk the pains of Hell. But at this point, they probably have still not proven the existence of their particular deity over all the others. This brings into question not just if you're wrong, but what if they are. With thousands of religions dead from the past or not yet made in the future, as well as hundreds existing currently, how could they possibly know theirs is right? Without proving their beliefs to be correct, they are committing the fallacy of special pleading. Furthermore, they are possibly risking their lives on a false religion. What if the Flying Spaghetti Monster is true? Shouldn't they accept it so that they can go to a heaven with a beer volcano and a stripper factory, rather than the FSM hell, which only has a stale beer volcano and an ugly stripper factory? This example applies to any and all religions until the right one is discovered (if it ever is at all).
Certainly these don't cover the more complex arguments such as the Kalam Cosmological argument, nor all of them that exist, but they are the ones the skeptic/atheist will probably come across in casual conversation with a layman wooer. I hope you've found this helpful, and are able to use them practically in your day to day. If not, well, that's your own bloody fault, isn't it?