Animal Rights and Vegan Advocacy

Nature Objections Section

Reasoned responses, organized as talking points, to common objections, concerns, and questions regarding animal rights and veganism.

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“Animals were put here for us.” To Do“animals were put here for us.” to do“animals were put here for us.” to do
“Plants are sentient and have feelings too!”“plants are sentient and have feelings too!”“plants are sentient and have feelings too!” [toc label="talking points"]this objection to animal rights and veganism is usually not from a concern for the well-being of plants but to illuminate a perceived inconsistency. if both plants and animals are sentient and have feelings, and if we abstain from eating animals for ethical reasons, then we must also abstain from eating plants.claims of plant sentience and intelligence make for provocative titles and seductive clickbait, but a closer consideration of the evidence renders these claims vacuous.

plants differ from animals in ethically significant ways.

plants cannot feel pain. because plants lack a brain, a central nervous system, and pain receptors, they cannot feel pain. plants may sense they are being eaten through mechanoreceptors, but they don't care.((“we asked a biologist if plants can feel pain.” vice. accessed july 26, 2017. https://www.vice.com/en_us/article/xd74nd/we-asked-a-botanist-how-sure-science-is-that-plants-cant-feel-pain-302 ))plants cannot experience emotions. emotions are processed in the hippocampus and amygdala regions of the brain—neither of which are present in a plant.((rand s. swenson, m.d., ph.d., “review of clinical and functional neuroscience.” dartmouth medical school, 2006. https://www.dartmouth.edu/~rswenson/neurosci/chapter_9.html ))plants have no self-awareness or sense of the future. thinking requires a brain, and without thought, there can be no self-awareness or sense of the future.plants do not have desires, preferences, or interests. there is no evidence that plants have the cognitive ability to have these traits.

eating animals kills more plants than eating plants.

if you actually believe plants are sentient and feel pain, then you will cause less plant pain by eating plants rather than animals. while this may seem counterintuitive, it is true, because animals are very inefficient at converting plant calories to animal calories. this inefficiency is in part because of the calories expended for metabolism as well as the calories and food that go into producing nonedible parts, such as bones, cartilage, feathers, fur, fins, skin, and organs.as indicated by feed-conversion ratios, it takes twenty-five pounds of feed to produce one pound of beef, nine pounds of feed to produce one pound of pork, and five pounds of feed to produce one pound of chicken.((professor smil vaclav. “eating meat: evolution, patterns, and consequences.” population and development review 28, no. 4 (2002): 599–639. http://home.cc.umanitoba.ca/~vsmil/pdf_pubs/pdr2003.pdf )) the total amount of plants consumed is far greater when you eat the animals that eat plants than when you eat plants directly.

there is no reason plants would experience pain.

because pain is a response to avoid tissue damage by withdrawing or fleeing, and since plants have limited ability to withdraw or flee, there is no reason they would have evolved to feel pain.leonardo da vinci realized this. in one of his notebooks, he said, "though nature has given sensibility to pain to such living organisms as have the power of movement—in order thereby to preserve the members which in this movement are liable to diminish and be destroyed—the living organisms which have no power of movement do not have to encounter opposing objects, and plants consequently do not need to have a sensibility to pain, and so it comes about that if you break them they do not feel anguish in their members as do the animals.”((da vinci, leonardo. leonardo da vinci’s note-books: arranged and rendered into english with introductions. empire state book company, 1908, 130 ))

some plants depend on being eaten for the survival of their species.

some plants depend on being eaten to enhance the chances that their species will survive. the indigestible seeds of the plants will be spread over a wide geographical area as the plants are eaten by animals and then deposited in the animals' excrement.

visceral reactions differ with plants and animals.

at a less cerebral and more visceral level, i think we all sense the difference between pulling up a dandelion and slitting the throat of a chicken. watching someone mow the lawn doesn't evoke the same reaction as watching someone kick a dog.

plants are sentient and intelligent only by the very broadest definitions.

plants are sentient and intelligent only in a way similar to how bacteria and other single-cell organisms are sentient or intelligent. that is to say, plants generate and respond to chemical and electrical signals.
“If we all go vegan, farm animals will either overrun the world or become extinct.”“if we all go vegan, farm animals will either overrun the world or become extinct.”“if we all go vegan, farm animals will either overrun the world or become extinct.”[toc label="talking points"]we often hear two related but opposite objections to animal rights and veganism—that if everyone went vegan, animals would either overrun the world or become extinct. of course, animals can't both overrun the world and become extinct at the same time. yet these complaints are sometimes voiced, oddly enough, one after the other by the same person. neither objection has merit. in the case of species extinction, we show that eating animals is the problem, not the solution to the problem.

as more people become vegan, we will gradually stop breeding animals.

animals will not overrun the planet, because people will not all go vegan at once. over fifty billion land animals are currently slaughtered annually for food,((“meat production continues to rise.” worldwatch institute, september 29, 2017. http://www.worldwatch.org/node/5443 )) but as more people go vegan, the demand for animal products will decrease, resulting in less breeding and slaughter.animal agriculture, as a profit-driven business sector, will breed into existence only the number of animals that will cover projected sales. it's a simple matter of supply and demand.

farm animals are genetic anomalies that we shouldn't continue to breed.

farm animals are far different from their natural ancestors. after decades of carrying out selective breeding without regard for the well-being of the animals being bred, we have sadly made them freaks of nature.chickens raised for meat are a prime example. they have more than doubled in weight in the past century, from 2.50 pounds in 1925 to 6.18 pounds in 2017,((“u.s. broiler performance.” the national chicken council (blog), september 26, 2017. http://www.nationalchickencouncil.org/about-the-industry/statistics/u-s-broiler-performance/ )) and a chicken's breast has been engineered to now be huge in relation to the rest of the chicken's body. also, the growth of these unfortunate birds has been accelerated to such an extent that the slaughter weight is reached in fewer than fifty-seven days.((“out of sight, out of mind.” georgians for pastured poultry, 2012. https://www.ciwf.com/media/1141326/outofsight-full-report.pdf ))the excess weight and rapid growth cause leg problems, skeletal abnormalities, heart and lung disease, footpad dermatitis, ascites and acute heart failure, and high mortality. walking becomes so painful that the birds move only to get food and water, spending most of their time lying down.((ibid.))other farm animals suffer similar deformities from selective breeding; the aim of such breeding is to produce the most meat, milk, and eggs in the shortest possible time with the least expense and the most profit.these innocent individuals deserve our moral consideration, but it makes no sense for them to carry on as species, except for perhaps as small numbers of individuals in sanctuaries. their bodies are frail from selective breeding, their capacity to positively contribute to the ecosystem is diminished due to their lack of independence from the agricultural systems that created them, and they cannot live on their own in the wild. they are creations of humankind and should be allowed to fade from existence.

animal agriculture is likely the greatest cause of species extinction.

it's ironic that one would be concerned about the extinction of selectively bred farm animals when animal agriculture is a major cause of species extinction—most likely the greatest cause of species extinction—launching the planet into what scientists call the sixth mass extinction.according to a systematic review published in science of the total environment in 2015, which analyzed over 140 research papers and studies, "animal product consumption by humans is likely the leading cause of modern species extinctions, since it is not only the major driver of deforestation but also a principle driver of land degradation, pollution, climate change, overfishing, sedimentation of coastal areas, facilitation of invasions by alien species, and loss of wild carnivores and wild herbivores."((machovina, brian, kenneth j. feeley, and william j. ripple. “biodiversity conservation: the key is reducing meat consumption.” science of the total environment 536 (december 2015): 419–31. https://doi.org/10.1016/j.scitotenv.2015.07.022 ))another study, published in 2015 in science advances, confirms what many scientists have been saying, reporting there being "an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already underway."((ceballos, gerardo, paul r. ehrlich, anthony d. barnosky, andrés garcía, robert m. pringle, and todd m. palmer. “accelerated modern human–induced species losses: entering the sixth mass extinction.” science advances 1, no. 5 (june 1, 2015): e1400253. https://doi.org/10.1126/sciadv.1400253 ))the studies cited here are just a couple of the many studies made by scientists in the last few years that reach essentially the same conclusions.

eating animals is the problem, not the remedy.

i hope you can see the absurdity in first declaring that we have to eat farm animals because they may overrun the earth if we don't and then proceeding to continue breeding said animals that might overrun the earth.we have shown not only that will animals not overrun the earth but also that animal extinction is caused by eating animals and is remedied by the world going vegan, not the other way around.
“Humans are natural omnivores—we digest meat, have canine teeth, and have front-facing eyes.”“humans are natural omnivores—we digest meat, have canine teeth, and have front-facing eyes.”“humans are natural omnivores—we digest meat, have canine teeth, and have front-facing eyes.”[toc label="talking points"]those objecting to veganism often bring up one or more in a series of related complaints: that a vegan diet is not natural, that humans are omnivores and can digest meat, or that canine teeth and front-facing eyes are indications we are predators and not prey.these protests are adequately dismissed with the first point below, which explains why they are not pertinent to the validity of veganism and therefore cannot diminish the case for veganism.although no further exploration of these claims is necessary once their lack of pertinence is demonstrated, we expound on these claims in case you're interested. it turns out that even if the objections were pertinent, they'd be nevertheless weak.

the case for veganism does not depend on humans being natural herbivores or having specific physical traits.

vegan diets are beyond sufficient for human health. even if humans were natural omnivores and our teeth and eye locations supported that assertion, the science is clear that a strictly herbivorous vegan diet is not only adequate but also beneficial to our health.this is confirmed by harvard medical school, mayo clinic, cleveland clinic, kaiser permanente, newyork-presbyterian, the academy of nutrition and dietetics operating in the united states, the dietitians of canada, the british dietetic association, the dietitians association of australia, and others.((see http://justiceforanimals.org/objections/quote-we-need-animal-products-to-be-healthy/ for statements and citations ))these prominent organizations and others could only have made statements declaring the adequacy and salubriousness of a vegan diet if science supported such statements. cleveland clinic even explicitly states, "there really are no disadvantages to a herbivorous diet!"((“understanding vegetarianism & heart health.” cleveland clinic, december 2013. https://my.clevelandclinic.org/health/articles/understanding-vegetarianism-heart-health ))the case for veganism has nothing to do with this issue. simply put, the case for veganism is that it's ethically wrong to cause unnecessary harm to animals. because it's not necessary to eat animal products for nutrition, any claims that we are natural herbivores are rendered meaningless.

the evidence is strong that we lean toward being herbivorous.

the fact that humans are behavioral omnivores and are able to get nutrition from both plants and animals says nothing about what is natural or optimum.our anatomy and physiology suggest that we are more herbivorous than omnivorous. a number of notable people have observed that anatomical and physiological traits of humans closely match herbivores'.dr. mills's the comparative anatomy of eating((mills, milton r. “the comparative anatomy of eating.” vegsource interactive inc 26 (1996). https://www.scribd.com/doc/94656/the-comparative-anatomy-of-eating )) shows we more closely match herbivores in eighteen traits, as summarized below.
  • intestines
    • small intestine
      • carnivore: 3–6 times body length
      • omnivore: 4–6 times body length
      • herbivore: 10–12+ times body length
      • human: 10–11 times body length
    • colon
      • carnivore: simple, short, and smooth
      • omnivore: simple, short, and smooth
      • herbivore: long, complex; may be sacculated
      • human: long, sacculated
  • teeth
    • incisors
      • carnivore: short and pointed
      • omnivore: short and pointed
      • herbivore: broad, flat, and spade shaped
      • human: broad, flat, and spade shaped
    • canines
      • carnivore: long, sharp, and curved
      • omnivore: long, sharp, and curved
      • herbivore: dull and short or long (for defense) or none
      • human: short and blunted
    • molars
      • carnivore: sharp, jagged, and blade shaped
      • omnivore: sharp blades or flattened
      • herbivore: flat with cusps vs. complex surface
      • human: flat with nodular cusps
  • saliva
    • carnivore: no digestive enzymes
    • omnivore: no digestive enzymes
    • herbivore: carbohydrate-digesting enzymes
    • human: carbohydrate-digesting enzymes
  • stomach
    • stomach type
      • carnivore: simple
      • omnivore: simple
      • herbivore: simple or with multiple chambers
      • human: simple
    • stomach acidity with food in stomach
      • carnivore: ≤ ph 1
      • omnivore: ≤ ph 1
      • herbivore: ph 4–5
      • human: ph 4–5
  • chewing
    • carnivore: none; swallows food whole
    • omnivore: swallows food whole or simple crushing
    • herbivore: extensive chewing necessary
    • human: extensive chewing necessary
  • nails
    • carnivore: sharp claws
    • omnivore: sharp claws
    • herbivore: flat nails or blunt hooves
    • human: flat nails
  • jaw
    • type
      • carnivore: angle not expanded
      • omnivore: angle not expanded
      • herbivore: expanded angle
      • human: expanded angle
    • joint location
      • carnivore: on the same plane as molar teeth
      • omnivore: on the same plane as molar teeth
      • herbivore: above the plane of the molars
      • human: above the plane of the molars
    • motion
      • carnivore: shearing; minimal side-to-side motion
      • omnivore: shearing; minimal side-to-side motion
      • herbivore: no shearing; good side-to-side, front-to-back motion
      • human: no shearing; good side-to-side, front-to-back motion
    • major muscles
      • carnivore: temporalis
      • omnivore: temporalis
      • herbivore: masseter and pterygoids
      • human: masseter and pterygoids
  • mouth opening vs. head size
    • carnivore: large
    • omnivore: large
    • herbivore: small
    • human: small
  • facial muscles
    • carnivore: reduced to allow wide mouth gape
    • omnivore: reduced
    • herbivore: well developed
    • human: well developed
  • liver
    • carnivore: can detoxify vitamin a
    • omnivore: can detoxify vitamin a
    • herbivore: cannot detoxify vitamin a
    • human: cannot detoxify vitamin a
  • kidney
    • carnivore: extremely concentrated urine
    • omnivore: extremely concentrated urine
    • herbivore: moderately concentrated urine
    • human: moderately concentrated urine
percy bysshe shelley was a poet, not a scientist, but it's interesting to note that he wrote an entire book, a vindication of natural diet, published in 1884, that drew on comparative anatomy to argue that humans were best suited to a vegetable diet.((shelley, percy bysshe. a vindication of natural diet. percy bysshe shelley. kindle e-book, a public domain book. vegetarian society, 1883. http://amzn.com/b0076qxqji )) this predates dr. milton mills's work, discussed above, by over 100 years.evolution and anthropology may support the contention that we are more herbivorous. biologist rob dunn declares in scientific american that "human ancestors were nearly all vegetarians." in making that assertion, and in questioning the validity of paleo claims, he deems it important to look at the diets of our ancestors at the time our guts were evolving. he states that for primates, a group to which humans belong, plants "were our paleo diet for most of the last thirty million years during which our bodies, and our guts in particular, were evolving. in other words, there is very little evidence that our guts are terribly special and the job of a generalist primate gut is primarily to eat pieces of plants."((dunn, rob. “human ancestors were nearly all vegetarians.” scientific american blog network, july 22, 2012. https://blogs.scientificamerican.com/guest-blog/human-ancestors-were-nearly-all-vegetarians/ ))dr. colin barras, a paleontologist and science writer, believes that "archaeologists tend to emphasise the role of meat in ancient human diets, largely because the butchered bones of wild animals are so likely to be preserved at dig sites. edible plants may have been overlooked simply because their remains don’t survive so well."((barras, colin. “ancient leftovers show the real paleo diet was a veggie feast | new scientist.” new scientist, december 5, 2016. https://www.newscientist.com/article/2115127-ancient-leftovers-show-the-real-paleo-diet-was-a-veggie-feast/ ))our inability to kill and eat animals and process meat without sophisticated tools is telling. omnivores and carnivores who eat animals have the athletic prowess and anatomical features necessary to not only catch and kill their prey but also to tear and rip apart the carcass and process it for eating.humans lack these features and must use sophisticated tools, such as spears and knives, to accomplish these tasks.the adverse effects of eating animal products suggest that we are more herbivorous. supporting the contention that our evolution and physiology are herbivorous is the overwhelming scientific evidence that eating animal products contributes to all manner of health problems, including increased risk for obesity, high blood pressure, diabetes, heart disease, and cancer.((m.d, michael greger, and gene stone. how not to die: discover the foods scientifically proven to prevent and reverse disease. 1 edition. new york: flatiron books, 2015 )) ((“the china study: the most comprehensive study of nutrition ever conducted and the startling implications for diet, weight loss and long-term health: thomas m. campbell ii and t. colin campbell: 8580001064130: amazon.com: books.” accessed january 12, 2018. https://www.amazon.com/china-study-comprehensive-nutrition-implications/dp/b006dukw0e/ref=tmm_hrd_swatch_0?_encoding=utf8&qid=1515791692&sr=1-1 )) ((davis, brenda, and melina vesanto. becoming vegan: the complete reference to plant-based nutrition (comprehensive edition). accessed january 12, 2018. https://www.amazon.com/becoming-vegan-reference-plant-based-comprehensive/dp/1570672970/ref=tmm_pap_swatch_0?_encoding=utf8&qid=1515791822&sr=1-1 )) ((“plantbasedresearch | an online library of research relevant to plant-based nutrition.” accessed january 12, 2018. http://plantbasedresearch.org/ ))

the notion of a natural diet is problematic.

the concept of a natural diet might make some sense in the context of gatherers and hunters. but since the invention of agriculture, with its selective breeding of both plant and animal species, the label loses its meaning.also, to make the claim that humans are natural omnivores, one needs to define what is meant by "natural" in this context. if by "natural" you are referring to the ability to obtain nutrients, then humans are omnivores, as we can digest both plants and meat. but, as shown earlier, that still cannot negate the case for veganism.if you mean it's natural because it's nutritionally the best diet for humans, then you are on shaky ground. there's an increasingly large body of research, as mentioned and cited above, supporting the contention that the closer we are to a varied herbivorous diet, the greater our general health and the lower our risk for a multitude of chronic diseases.finally, the claim that humans are natural omnivores can be thought of as an example of the naturalistic fallacy. that is to say, being natural doesn't make something ethically or nutritionally sound.

canine teeth are not indicators of dietary requirements.

as elaborated on earlier, the argument for veganism does not depend on humans having any specific physical traits. but the part of the objection that pertains to canine teeth is discussed here only because it is frequently voiced.hippopotamuses, gorillas, camels, and saber-toothed deer all have sizable canines, and all are herbivorous. herbivores use canine teeth in various ways. sizable canines in herbivores are often for defense. the relatively short, blunted canines in humans can assist in biting into hard, crunchy plants (such as apples) and ripping vegetable matter, preparing the food for grinding by the other teeth. one thing seems obvious—human canines are not adequate to kill prey or tear raw flesh for eating.

front-facing eyes are not necessarily indicative of predator status.

the claim is made that since many prey animals have eyes on the side of the head and many predator animals have eyes on the front of the head, it follows that humans, who have eyes on the front of the head, are designed to eat copious amounts of meat.the point is made moot, however, not only by the fact that the argument for veganism does not depend on physical traits but also by the fact that our closest relatives in the animal kingdom, the primates, have eyes in the front of the head.at least three advantages of frontal eyes for primates have been proposed.binocular vision is crucial for the manipulation of plant foods. a study titled "binocularity and brain evolution in primates," published by the national academy of sciences, concludes that "fine-grained stereopsis [binocular vision] is likely to be critical for the visually guided, delicate manipulation of plant foods."((barton, r. a. “binocularity and brain evolution in primates.” proceedings of the national academy of sciences of the united states of america 101, no. 27 (july 6, 2004): 10113–15. https://doi.org/10.1073/pnas.0401955101 ))the ability to "see through" foliage is advantageous. theoretical neurobiologist mark changizi proposes in the journal of theoretical biology the "x-ray vision" hypothesis. according to changizi, front-facing eyes gave our ancestors the advantage of being able to "see through" the cluttered foliage in the forest. you can see this effect, he states, by placing a finger in front of your eyes and noting that the finger does not block the view of anything behind it.((changizi, mark a., and shinsuke shimojo. “‘x-ray vision’ and the evolution of forward-facing eyes.” journal of theoretical biology 254, no. 4 (october 21, 2008): 756–67. https://doi.org/10.1016/j.jtbi.2008.07.011 ))arboreal locomotion requires accurate depth and distance perception. the depth and distance perception afforded by front-facing eyes was useful to our ancestors in jumping from branch to branch and tree to tree. this idea was proposed in 1922 by edward collins and has subsequently been expanded and refined.((goldman, jason g. “evolution: why do your eyes face forwards?” bbc, october 28, 2014. http://www.bbc.com/future/story/20141013-why-do-your-eyes-face-forwards ))
“Animals eat animals – it’s the circle of life” To Do“animals eat animals – it’s the circle of life” to do“animals eat animals – it’s the circle of life” to do
“If we didn’t milk cows, their udders would explode” To Do“if we didn’t milk cows, their udders would explode” to do“if we didn’t milk cows, their udders would explode” to do
“Fish are not really animals and don’t feel pain” To Do“fish are not really animals and don’t feel pain” to do“fish are not really animals and don’t feel pain” to do