Appeal to nature



We're human beings and the sun is the sun — how can it be bad for you? I think we should all get sun and fresh air. I don't think anything that is natural can be bad for you — it's really good to have at least 15 minutes of sun a day. An appeal to nature is a logical fallacy that occurs when something is assumed to be good because it is "natural" or bad because it is "unnatural".

The fallacy is, naturally, a naturalistic fallacy and thus an informal fallacy. The fallacy can be exemplified in one of three ways, with P1 and P2 being premisses and C being the conclusion that follows from them:      Notably, the appeal to nature is often implicit in marketing, simply by using terms like "natural", "all-natural", "natural goodness", "organic", "pesticide-free", or "no artificial ingredients".

Deconstruction
Appeal to nature is a fallacious argument because the mere "naturalness" of something is unrelated to its positive or negative qualities – natural things can be bad or harmful (such as infant death and the jellyfish above), and unnatural things can be good (such as clothes, especially when you are in Siberia). Another problem is the distinction between what is "natural" and what is not, which can be murky: crude oil occurs naturally, but it's not something you'd like poured on seabirds or your garden. When does a product stop becoming natural? Any degree of human involvement? If that were the case, most of the fruits, vegetables, meat, seeds, and bread we eat don't qualify as natural as they've been selectively bred by humans for countless generations that they separated from their wild forms. Yet, no one ever rejects an apple in the organic grocery store as "unnatural." The word "natural" has no exact definition and can be used in multiple ways, thus allowing equivocation.

An excellent example of how tangled the concepts of "natural" and "non-natural," "desirable" and "undesirable" can become is the heart medication digoxin. It's a natural product of the foxglove plant (Digitalis spp.), which is quite poisonous as a plant. It is chemically extracted, or sometimes chemically synthesized, and dispensed in pill form because it relieves heart arrhythmias at therapeutic levels. However, at toxic levels, it causes potentially fatal heart arrhythmias — in fact, it is one of the plant toxins that makes foxglove so poisonous. There is a relatively narrow window between therapeutic and toxic levels. (One notable healthcare serial killer, used it as his killing agent of choice.) So is digoxin natural or non-natural? Desirable or undesirable?

As Harriet Hall noted: There is a reason pharmacology abandoned whole plant extracts in favor of isolated active ingredients. The amount of active ingredient in a plant can vary with factors like the variety, the geographic location, the weather, the season, the time of harvest, soil conditions, storage conditions, and the method of preparation. Foxglove contains a mixture of digitalis-type active ingredients but it is difficult to control the dosage. The therapeutic dose of digitalis is very close to the toxic dose. Pharmacologists succeeded in preparing a synthetic version: now the dosage can be controlled, the blood levels can be measured, and an antibody is even available to reverse the drug's effects if needed.

In other words, whereas medicinal plants contain variable and unpredictable quantities of pharmacologically active substances, drugs are precisely dosed and you always know the exact amount of active ingredient you are getting.

The problem with "natural living"
Appeals to nature are often encountered in advocacy for alternative medicine, food woo (organic food, vegetarianism, veganism, raw foodism, and paleo diet), general lifestyle woo, as well as in anti-industrial and anti-technological rhetoric, usually exhibiting themselves as something like: "Use this 100% natural herbal supplement, not that Big Pharma drug! Artificial chemicals are bad for you!"

- Naturopaths obviously

This is obviously flawed, as in the following "reasoning": Arsenic is natural, and therefore it is better for you than the unnatural (hence bad) acetaminophen in Tylenol. Of course, very few people actually take the appeal to nature to its logical conclusion, so they instead prefer to handwave the issue of toxic plants away with some non-reason that could perhaps be satirically described as "All plants are natural. But some plants are more natural than others."

In favor of the idea that it is better to "live naturally," some note that in earlier eras, when people "lived naturally," there were fewer cases of diseases commonly associated with the modern era, such as cancer or Alzheimer's. They argue that this is because of the lack of "synthetic" disease-causing substances in those times. However, there is another, more likely, explanation. Cancer and Alzheimer's are primarily diseases of old age. During the era of "natural living," people had shorter lifespans, so they did not generally live long enough to develop these diseases. Another common argument is that wild animals do not succumb to chronic illnesses, unlike humans or their domesticated pets. This is not particularly convincing either, as this quote illustrates:

A study of over 50 species of animals published in 2016 showed that 84% of species studied live longer in zoos than in the wild, saying, "zoos evidently offer protection against a number of relevant conditions like predation, intraspecific competition and diseases."

The false dichotomy of natural and synthetic
Usually, the word "natural" is used by alternative practitioners to mean "not synthetic," a substance not formed from chemical reactions caused by human intervention. However, in practice, alternative medicine supporters may be confused about what constitutes a "natural" product. Many alternative medicine advocates will complain about "allopathy" using "chemicals" (meaning isolated substances) instead of plants, yet at the same time see no contradiction in using isolated active ingredients such as essential oils, glucosamine, glutamine, laetrile, chelation drugs, Tetrasil, Miracle Mineral Supplement, or any of the other countless non-herbal alternative medicines available, many of which are synthesized – like pharmaceuticals – and differ from conventional drugs only in that they are (usually) unapproved and unproven. Grapefruit seed extract is criticized by some for consisting of unnatural chemicals, while others hail it as a natural remedy. Some believers in the superiority of nature (some naturopaths, for instance) have no qualms using conventional pharmaceuticals but arbitrarily classify some as being "good" and others as being "bad" for no apparent reason other than "I said so." In other words, even believers in the appeal to nature may not agree on what the word "natural" means.

Furthermore, alternative medicine's obsession with "naturalness" relies on a premise with no scientific or rational backing. If, as the appeal to nature posits, synthetic substances were lethal and natural ones were perfectly safe (or at least much less harmful), then the differences between these alleged types of molecules would be enormous, and it would be the easiest thing in the world to distinguish between them. Similarly, it should be possible to identify the chemical reactions that can turn "natural" compounds into their "synthetic" counterparts (for instance, "natural" water into "synthetic" water). However, no evidence has been provided to support either claim.

This obsession can lead to some amusing incidents. One herb company chemically tested synthetic and natural raspberry ketones to determine whether it was possible to distinguish between the two. They couldn't find any difference. Rather than conclude the synthetic and natural molecules were precisely the same, they decided not to sell the product at all, just in case.

All drugs and synthesized compounds have their origins in nature. Supposedly, if the substances were brought together by humans, the product would be "synthetic," whereas if they were combined by a force of nature, like gravity or wind, the product would be "natural." But if reactants were brought together by a human instead of a mindless force or some animal other than Homo sapiens, why would this modify the particles' nature, causing them to be "synthetic" and somehow inferior? Do humans have some negative aura that influences substances from a distance? And why doesn't this apply to homeopathy, which claims man-made homeopathic water is better than natural water?

There is a hidden premise that humans possess some taint that is transferred to anything they create, which is absent from anything made by absolutely any other species in existence. Inherent in the premise is that humans are not part of nature. This is ridiculous because we are animals that evolved in nature, as other animals did. The sole difference is our intelligence. And if the one who appeals to nature believes that applying intelligence to the things we create instead of doing it randomly is bad, then there's probably nothing you can say to them.

Broad and far-reaching conclusions about the fundamental nature of matter could be drawn based on scientific experiments conducted by (say) particle physicists; they could not be drawn based on flimsy comparisons such as those invoked in support of the appeal to nature (see below).

Testing and safety
When applied to medicine, the appeal to nature generally rejects rigorous scientific testing, focusing instead on the traditional use of particular substances for medical purposes (appeal to tradition). Counterexamples to the appeal to nature's insistence that "natural" traditional remedies must be safe include belladonna (Atropa belladonna), lead, asbestos, comfrey, and tobacco, among others. Nowadays, these sorts of products have been banned, so, in general, only the harmless (and usually, though not always, useless) ones remain.

The appeal to nature is often accompanied by comparing the side effects of some drug and some herbal supplement, with the former being more numerous and severe than the latter. It is argued that this is because of some property inherent to "natural" objects that makes them safer than non-natural ones. This comparison is flawed, however.

Modern medical drugs are tested very thoroughly, through trials involving vast numbers of people and extending over long periods, with reporting systems in place to detect any possible (and potentially very rare) adverse effects after they have been launched on the market, leading to the well known lengthy lists of side effects. The use of large cohorts is necessary, as the frequency of some side effects can be as low as 1 per 100,000 patients.

By contrast, herbal supplements have not undergone sufficient study necessary for regulatory approval, and side effects for herbal products are not as well monitored or recorded, so any adverse effects may be ignored or not reported. (Under-reporting of adverse effects is a prevalent issue for drugs and herbal supplements, but likely more so in the latter case. ) The relative lack of study into the safety of herbal supplements poses a significant problem, as the experience- and anecdote-reliant approach favored by alternative practitioners is incapable of detecting side effects that are rare or manifest symptoms only after a long time and is often the real reason for the short side effect lists of herbal supplements. As Steven Novella noted in an article on birthwort: Common use may be enough to detect immediate or obvious effects, but not increased risk of developing disease over time. That requires careful epidemiology or specific clinical studies. We know about the risks of prescription drugs only because they are studied, and then tracked once they are on the market. Without similar study and tracking there is simply no way to know about the risks of herbal products.

Once these all-natural remedies are tested, they are often proved to have side effects that can be just as bad as or even worse than conventional medicines. As epidemiologist Geoffrey Kabat noted:

What is essential to realize is that the effects of Aristolochia [birthwort] were identified only thanks to the large cluster of cases of kidney failure occurring in young women who had attended the same spa. It is much more likely that isolated cases will go unnoticed, as happened with ephedra, and it could take years to identify a common cause.

People failed to recognize the nephrotoxic effects of Aristolochia in spite of its use in many cultures worldwide over thousands of years. In an interview, [Arthur P.] Grollman explained why: “The reason, of course, is quite simple. It's painless, and the damage happens much later, so you don't put together the fact that you took this medicine and four years later, you have kidney failure. It's been part of Ayurvedic, European, Chinese, and South American medicine for centuries. All of the great civilizations have used it. And not one reported its toxicity until the Belgians did 20 years ago. There are certain things that tradition can't tell you."

Also, a side effect profile of a given quantity of a herb and that of the same quantity of a drug derived from it are not necessarily comparable. A drug is a pure active ingredient, whereas a plant may contain hundreds of different chemicals, of which only a few may actually have medicinal effects. Steven Novella noted, "The fact that individual chemicals are not purified and given in precise amounts does not mean they are not pharmacologically active chemicals – it just means that when taking an herbal remedy, you are getting a mixture of many chemicals in unknown doses." It would not be surprising for a given quantity of a drug to be stronger (and hence have more or more severe side effects) than the same quantity of the plant it is derived from; the drug would contain more active ingredient per weight than the plant. For this reason, some plants may be safer than their pharmaceutical derivatives, but this does not imply that they are also more (or even just as) effective, and this certainly could not be extended into a general rule applicable to all or even most plants.

It is often claimed that herbal medicine "is food, so it must be safe." Of course, just because some plants are food does not mean they all are. Many, if not most, of the herbs in herbal supplements sold for therapeutic purposes have no nutritional value and are taken solely for their pharmacological effects on the body. To quote Steven Novella:

With food and food ingredients the FDA does not require evidence of safety if the ingredient is generally recognized as safe. This might make sense when referring to foods that have been eaten by humans for a long time. Although the logic is still dubious, it's just practical – the FDA could not take upon itself the task of proving that every food eaten by humans has no significant negative health consequences. It is more a recognition of practicality than reality. […] Herbal remedies are drugs, plain and simple. They contain chemicals that are ingested on a regular basis for their pharmacological effects. The fact that they derive from plants is irrelevant.

Not to mention that many natural foods are quite unhealthy and can have detrimental effects on the human body.

Politics
The appeal to nature is also a tool for criticizing technological advancements or behaviors perceived to undermine cultural norms. A typical example of this appeal is to claim that homosexuality is immoral because it is unnatural. The logic is that since sexual reproduction involves intercourse between a single male and a single female, any deviation from this interaction must go against our natural design as humans. This argument is fallacious for no reason other than the many examples of homosexuality found in animals.

Similarly, scientific advancements that allow people to overcome normal biological constraints may be disparaged for being unnatural, often by claiming that scientists are attempting to "play God". Cloning and gene editing, for example, have been regarded as unethical for interfering with the natural order of human life or creating life outside of the process defined by nature.

Of course, these appeals fall into the same trap as the medical examples above. In these cases, the exact definition of "natural" can be nebulous or ignore clear examples that contradict the argument. For instance, in the case of homosexuality, various non-human animals also exhibit homosexual behavior, raising the question of how this behavior can be unnatural if it occurs in nature. Trying to further define "natural behavior" in terms of normal sexual behavior would be circular reasoning.

Likewise, accusations of science or technology playing God and going too far by messing with natural processes fail to define the "natural process" and why human intervention of any form is "unnatural". Other advancements, such as farming and construction, involve configuring materials to create products that would not otherwise occur in nature. Yet, no one accuses farmers or architects of disrupting the natural order. The only real difference is that the criticized advancements have not yet become commonplace, and we do not currently take them for granted.

Examples
A vast range of natural things is bad and frequently fatal to humans. These include naturally-found chemicals such as cyanide, an enormous number of diseases and contagions, including smallpox, influenza, HIV/AIDS, bubonic plague, and tuberculosis, a list of toxic plants that is too long to mention, natural disasters such as tsunamis, volcanic eruptions, earthquakes, hurricanes, tornadoes, and asteroid impacts, harmful minerals such as anglesite, asbestos, and chalcanthite, animals such as lions, sea kraits, cassowaries, black widows, Japanese hornets, and poison dart frogs, and animal corpses. In several cases, people have died from starvation after adopting excessively restrictive "natural" diets, such as "Kokovore" August Engelhardt and several cases of young children subjected to mismanaged vegan diets. On the other hand, fertilizers, many modern medicines, hygiene, and semiconductor-grade silicon are not of natural origin, but they significantly improved the length and quality of life of individual humans and societies.

Individual foods
Proponents of various food and diet woo use the appeal to nature to stress what kinds of food we should put into our body to reduce toxins, become better attuned with our ancestors, or avoid oppression from shady cabals like Big Dairy. Adherents of raw foodism, for example, argue that cooking food creates harmful toxins that are not present naturally, and of course, any existing bacteria can't be that dangerous. Similarly, the construction and development of the paleo diet (often referred to as the "caveman diet") has usually centered around foods consumed by people that live more "natural" lives or foods that have existed for tens of thousands of years and thus must be perfectly healthy. Genetically modified food is also attacked as "unnatural," ignoring that the basic science behind genetic modification has been used in farming practices for millennia. In the U.S., the food industry, aided by the Food and Drug Administration's lack of regulation on the term, has also capitalized on the "all-natural" craze. For instance, we have "all-natural" Sprite, which uses high-fructose corn syrup (HFCS), produced by a centrifuge. However, this still raises the question of when something becomes or ceases to be "natural". Using the above example, all of the materials used to make HFCS do, in fact, come from raw materials. Putting a line in the sand as to using a centrifuge is arbitrary at best (e.g., how is the centrifuge less natural than the distillery used to make essential oils?).

Hidden in the premise of the appeal is that any food found in nature must be safe. However, some foods are naturally toxic, even in unadulterated or uncontaminated forms. This is because there is a war on for survival, and all plants contain natural pesticides that they use to deter herbivory. Plant domestication has generally reduced the natural pesticide content of foodstuffs. Still, it hasn't entirely eliminated it (and not all of it needs to go away, per se, or we'd have vulnerable crops instead). Some animals are also toxic to eat, including some  and  This section contains foods that are sometimes toxic to consume, not foods that merely contain toxins (almost all plant foods contain toxins naturally). See also "Naturally Occurring Food Toxins" for a review of hazardous foods.

Ackee
Ackee (Blighia sapida, Sapindaceae family) is a popular Jamaican fruit that was originally imported from Africa, where it is also eaten. It causes because of the natural presence of hypoglycin A in the fruits. When the fruits are fully ripe, hypoglycin A is present at only <0.1 ppm, but unripe fruits can contain 1000 ppm, which can be lethal.

Beans
Aside from being a magical fruit, many varieties of beans are actually toxic and contain high amounts of Luckily, this toxin breaks down via boiling.

is a disease caused by, among other things, the consumption of fava beans (Vicia faba). The disease only affects people with a specific genetic predisposition common in people of Mediterranean and African origin. Symptoms include jaundice, hemolytic crises, diabetic ketoacidosis, and acute kidney failure.

Cassava
Cassava (Manihot esculenta), also known as yuca or manioc, is a starchy root that is a dietary staple in some parts of the world. It is also naturally high in cyanide. It has caused intoxication, goiters, ataxia, partial paralysis, and death when not properly prepared. The bitterer varieties (higher in cyanide) are often preferred by farmers because they are better pest deterrents.

Cycad
In Guam, cycad (Cycas micronesica) seeds were traditionally made into flour and eaten as a dietary staple. Cycads in Guam are symbiotic with a photosynthetic bacteria that enables the plant to produce the toxin (BMAA). Chamorro people of Guam and Rota islands eating a traditional diet were 50-100 times more likely to have amyotrophic lateral sclerosis/parkinsonism-dementia complex (caused by BMAA) than other people.

Elderberry
Elderberry (Sambucus spp.) is a genus of plants, nearly all of which are high in cyanides. If not adequately prepared (fully ripe and cooked), elderberry juice can cause sickness.

Fish
Predator species of reef fish can bioaccumulate ciguatera toxin produced by dinoflagellates. Symptoms include nausea, vomiting, diarrhea, headaches, muscle aches, paresthesia, numbness, ataxia, vertigo, and hallucinations. Ciguatera cannot be eliminated by ordinary cooking.

Pufferfish (family Tetraodontidae) are considered a delicacy in Japan, known as fugu (河豚). Pufferfish naturally contain tetrodotoxin, which may originate from their intestinal bacteria. Fugu chefs are specially trained to remove enough parts of the fish to prevent death but sometimes induce euphoric feelings from intoxication, but death occurs occasionally.

Escolar (Lepidocybium flavobrunneum) and oilfish (Ruvettus pretiosus) (both in the family Gempylidae) are high in oil content but are also high in indigestible wax esters, which can cause oily diarrhea, nausea, headache, and vomiting. Italy and Japan have banned the sale of these two fish, and other countries have restricted their sale.

Lychee
Lychee (Litchi chinensis, Sapindaceae family) is native to China and is mainly grown in India and China. Outbreaks of noninflammatory encephalopathy in India and Vietnam have been linked to lychee consumption, with symptoms similar to Jamaican vomiting sickness. Lychee sickness is also due to the presence of hypoglycin and a similar toxin, methylene cyclopropyl glycine, in the fruit.

Mushrooms
There are many species of mushrooms with widely ranging levels of toxicity. They range from the (not food, but sometimes mistaken for food) to the sometimes sickening (wild food) to the domesticated (e.g., the common mushroom Agaricus bisporus). Some wild species only sicken some people, e.g., A. hondensis, whereas others are often deadly even though they are delicious (Amanita phalloides). There are many erroneous folk beliefs about whether mushrooms are safe, but only science-based methods are reliable.

Pokeweed
Pokeweed (Phytolacca americana) has traditionally been used as a food and herbal medicine in the United States, particularly in southern Appalachia. Pokeweed contains several toxins in high levels, including saponins and saponin-like chemicals.

Potato
Potatoes (Solanum tuberosum, family Solanaceae) which have turned green from Sun exposure or age have increased levels of solanine (a glycoalkaloid). Potato poisoning from excessive solanine can cause death, vomiting, diarrhea, abdominal pain, and, in severe cases, depression of the central nervous system. Cooking potatoes does not eliminate solanine levels. Cases of potato poisoning were reported in 1899, 1918, 1922, 1925, 1948, 1952, and 1983.

The fruit of the potato is also packed with solanine; there is a reason you didn't know potatoes had fruit.

Wheat
Wheat and other food crops in the Balkans have been shown to bioaccumulate the nephrotoxic aristolochic acid released from Aristolochia plants. These crops in the Balkans are responsible for Balkan endemic nephropathy.

Carcinogens
The International Agency for Research on Cancer (IARC) regularly evaluates the evidence for various agents (chemicals, activities, and exposure situations) as to whether the agents are likely to be human carcinogens. The highest level of evidence, Group 1, is regarded as definitively "Carcinogenic to humans", usually based upon strong epidemiological evidence but also with supporting evidence from animal and mechanistic studies. As of March 2021, there have been 129 evaluations for Group 1 carcinogens. Of the 116 evaluations as of July 2016, 67 (58%) could be regarded as being from naturally-occurring chemicals, activities, or exposure situations.

This is an imperfect count of natural carcinogens, but it nonetheless shows that natural is not inherently "good" and synthetic is not inherently "bad". The latter is the case because several synthetic cancer treatment drugs are effective in treating cancer but also carry a usually smaller risk of causing cancer. There is some redundancy in the table, e.g., several types of radiation exposures have separate evaluations even though the mechanism of carcinogenesis is basically the same, which could be considered a type of double counting. The question of what is and is not natural is not always clear-cut, e.g., tanning beds seem synthetic, but the mechanism of carcinogenesis is the same as that of natural Sun exposure.

In an analysis of chemicals tested for carcinogenicity in rodents at high doses, 57% of naturally-occurring chemicals were found to be carcinogenic vs. 60% of synthetic chemicals.