5X5 Episode 110
- S: Steven Novella
- E: Evan Bernstein
- J: Jay Novella
- R: Rebecca Watson
- B: Bob Novella
You're listening to the Skeptics' Guide 5x5, five minutes with five skeptics, with Steve, Jay, Rebecca, Bob and Evan.
S: This is the SGU five by five and tonight we're talking about the naturalistic fallacy. This is a logical fallacy that takes the form of assuming or claiming that something is better, superior in some way, because it is "natural". There are many problems with this line of reasoning. One is that it's very difficult to define what one means by the word natural. There's no real operational definition or sharp line of demarcation between what is natural and what is not natural. But more importantly just because, for example, a remedy is perceived as being natural that does not mean that it is magically safe and effective. Often the naturalistic fallacy is used instead of evidence, actual evidence, for safety and efficacy. This is rife, for example, in the herbal remedies market. Herbs are often thought of as being something other than drugs simply because they're "natural". Ignoring the fact that that's completely irrelevant, if an herb is taken it contains chemicals - that's a drug - herbs are in fact often used as drugs, the fact that they are considered to be natural is completely irrelevant to the chemicals that they contain and their action inside the body, and that is, I think, an excellent example of the naturalistic fallacy.
B: The naturalistic fallacy has two fundamental aspects to it. There's the appeal to nature that Steve just mentioned; natural things are fundamentally good, and unnatural things aren't. Related to this appeal to nature is the act of deriving and 'ought' from an 'is' This means that the premise of your argument describes what 'is', but the conclusion unfairly uses that to determine what 'ought' to be. A classic example is:
- One All men are mortal.
- Two Socrates is a man.
- Three Therefore Socrates is a philosopher.
A reasonable argument can not add something entirely new in their argument, which is what essentially is being done when committing a naturalistic fallacy. There's no mention of philosophers in the premise, how then can a conclusion be derived about them. Philosopher David Hume first discussed this 'is-ought' fallacy back in the 1700s. He described a logical gap between 'is' statements and 'ought' statements. How do you connect descriptions of what 'is' - something that science is great at - with descriptions of what 'ought to be' - something best handled by ethics and aesthetics. This is not impossible to accomplish, but it has to be done carefully with a well thought out, reasoned and supported argument, something sorely lacking in most abusers of the naturalistic fallacy.
E: The argument that there's some sort of intrinsic virtue in things that are natural appears to a certain set of senses inside of us. So, we might picture in our mind this utopian nature scene with no human embellishments or infections, just the trees and the fields, the streams and the lakes, insects and birds, wild animals, wild flowers, and they all live in some sense of balance and harmony, so this is nature, right? Well what possible malignancies could there possibly be in such a paradise? Well, how about arsenic, for example. Arsenic is a naturally occurring chemical, when ingested by people it's a deadly poison, and it can be found in foods such as apricot pits, peach pits, apple seeds and cherry seed also contain certain amounts of cyanide, and in fact arsenic contamination of groundwater is a problem that affect millions of people across the world, but, it's all natural. And how about kidney beans or lima beans? If you consume as few as five of these uncooked beans, poisonous effects can being to occur. Some other natural toxins include certain varieties of algae, the algae is eaten by bottom feeding shellfish, and then we eat the shellfish, which people around the world make part of their regular diet. There are mycotoxins, which are toxins derived from mushrooms, and they infect plants and flowers and legumes, nuts, vegetables, you name it, practically anything we consume in nature, the mushrooms have an effect on. Venom from snakes, spiders, scorpions, are natural, oh and for the bee-string therapists out there? Honey bee stings release hormones that prompt other nearby bees to come along for the attack, ouch, and we can't forget out friend Naegleria fowleri, which is an amoeba which attacks the body through the nasal cavity, and it eats its way up to the brain, and these are naturally occurring organisms that thrive in ponds and other still bodies of water where people like to go swimming, say, on a hot summer day. Or, if you want to get really hardcore, let's come up with something called Uranium Therapy for people. You know, uranium is just about as natural as anything else on the planet, and it was Randi who succinctly encapsulated this aspect of the naturalistic fallacy, as only Randi can when he once said, "Bird shit and gravel are natural, but I won't eat them".
S: Yeah, basically, most stuff out there in nature is poisonous to some degree. I would not advise going out into the woods and eating a random plant. Chances are you're going to get an upset stomach at best, and may be ingesting a deadly poison at worst.
R: And of course, the naturalistic fallacy isn't just used for things that we ingest and alternative medicine, things like that. It's also often used in the case of arguing against certain social concerns like homosexuality. One common argument is that homosexuality is not natural and therefore it is wrong. This of course ignores the fact that there are plenty of animals that do engage in some kind of homosexual behaviour. For instant, humans live in high rises, and no other animal does. That doesn't mean that it's necessarily bad or evil, and so it is with homosexuality.
J: I took this at a different angle, I wanted to talk about when people use the naturalistic fallacy in conversation and what they talk about and some of the mistakes that they make. So, you'll quite commonly hear people say that, "if it's natural, it's good." I hear this with the people I talk to at work all the time, "it's natural, it's natural", comes up in conversations. The fallacies commonly cited reason why people don't eat something like zero calorie sugar substitute like Splenda or Equal, and I think you'd be surprised if you take a look at what those two products are made out of, how not dangerous they are. As a quick example, Splenda is made out of sucralose and is absolutely not dangerous at normal quantities, just like everything else. You could find the term "all natural" on food products, herbal remedies, even cleaning chemicals, and "all natural" is a nebulous term, but most people think it means it that it's naturally occurring, or non-processed, created by nature, The fact is, and I think a lot of people would be surprised to find out, is that most of our fruits, vegetables and farm animals have been selectively bred for flavour and yield size for thousands of years, and I always bring this one up when discussing the naturalistic fallacy with people that I'm talking to, typically at work, and I question you guys, is something still natural is mankind has selectively bred it to become something else? What's the difference between natural selection versus man-made selection.
S: Yeah, I mean that's a good point that I started out with, that is, that "natural" is a vague term, it doesn't really have any clear definition and therefore it's very difficult to apply in any kind of rational sense, but even if we did have a workable definition such as, "occurring in nature", why would something that occurs in nature be more likely to be safe and effective or to be non-toxic to humans. Nature doesn't care about us, we're just one species of ten million, there's no particular reason why something that is natural would not be harmful to us. In fact, some plants and animals specifically evolved things to be toxic to us, so it really fails at every level, but it is I think a testimony to, I think, the unbelievably effective marketing strategy and propaganda that is almost taken as a given in our culture that something that is natural is better, despite the fact that there is simply no logic behind that at all.
S: SGU 5x5 is a companion podcast to The Skeptics' Guide to the Univese, a weekly science podcast brought to you by the New England Skeptical Society in association with skepchick.org. For more information on this and other episodes, visit our website at www.theskepticsguide.org. Music is provided by Jake Wilson.