[1] Individuals who promote meat consumption do so for a number of reasons, such as health, cultural traditions, religious beliefs,[2] and scientific arguments that support the practice.
[11] The World Scientists' Warning to Humanity (2017), the most co-signed scientific journal article in history, called (among other things) for a transition to plant-based diets in order to combat climate change.
Pythagoras, a Greek mathematician and philosopher who lived during the 6th century BC, made the case against eating animals on grounds of their having souls like humans.
Taking an entirely different approach, Plato, an Athenian philosopher who lived during the 4th century BC, argued that meat is a luxury item that requires a lot of land to procure.
[24] Ethical vegetarian concerns have become more widespread in developed countries, particularly because of the spread of factory farming, more open and graphic documentation of what human meat-eating entails for the animal,[25] and environmental consciousness.
[31][32] Eugene Linden, author of The Parrot's Lament, suggests that many examples of animal behavior and intelligence seem to indicate both emotion and a level of consciousness that we would normally ascribe only to our own species.
One] only [has] to watch how cows and lambs both seek and enjoy pleasure when they lie with their heads raised to the sun on a perfect English summer's [day, just] like humans.
Steven Best also challenges this notion, and argues that factory farm conditions "resemble the mechanized production lines of concentration camps" where animals are "forced to produce maximal quantities of meat, milk, and eggs—an intense coercion that takes place through physical confinement but also now through chemical and genetic manipulation.
"[40] David Nibert says that sentient animals are treated as mere inanimate objects and "biomachines" in factory farms, or CAFOs, where they are often confined in darkness with no opportunity for engaging in natural activity, are mutilated to prevent pathological behaviors in overcrowded conditions, and genetically manipulated to the point where many cannot even stand.
[41] David Benatar contends that of the 63 billion land animals killed annually to provide humans with meat products, the vast majority of them die painful and stressful deaths.
[42]Writing in Current Affairs, Nathan J. Robinson describes the billions of non-human animals that suffer and die at the hands of human beings for consumption as a "holocaust" and, citing Jeremy Bentham's formulation "The question is not, Can they reason?
The intrepid Midgley, on the other hand, seems willing to speculate about the subjective experience of tapeworms ... Nagel ... appears to draw the line at flounders and wasps, though more recently he speaks of the inner life of cockroaches.
[48] In an article written for The New York Times, Carol Kaesuk Yoon argues: When a plant is wounded, its body immediately kicks into protection mode.
Inside the plant, repair systems are engaged and defenses are mounted, the molecular details of which scientists are still working out, but which involve signaling molecules coursing through the body to rally the cellular troops, even the enlisting of the genome itself, which begins churning out defense-related proteins ...
No forests are cleared for oysters, no fertilizer is needed, and no grain goes to waste to feed them—they have a diet of plankton, which is about as close to the bottom of the food chain as you can get.
When people choose to do things about which they are ambivalent and which they would have difficulty justifying, they experience a state of cognitive dissonance, which can lead to rationalization, denial, or even self-deception.
In addition, it can be virtually assured that the deer was never bred or raised in unnatural conditions, confined to a cage, fed an unnatural diet of grain, or injected with any artificial hormones; however, since the necessary act of killing a deer to procure the venison is generally much more apparent to anyone who encounters this sort of meat, some people can be even more uncomfortable with eating this than meat from animals raised on factory farms.
"[56] The livestock sector is probably the largest source of water pollution (due to animal wastes, fertilizers, and pesticides), contributing to eutrophication, human health problems, and the emergence of antibiotic resistance.
[56][58][59] A 2017 study by the World Wildlife Fund found that 60% of biodiversity loss can be attributed to the vast scale of feed crop cultivation needed to rear tens of billions of farm animals.
[62] A 2017 study published in the journal Carbon Balance and Management found animal agriculture's global methane emissions are 11% higher than previously estimated.
[63] In November 2017, 15,364 world scientists signed a warning to humanity calling for, among other things, "promoting dietary shifts towards mostly plant-based foods.
Following environmentalist Aldo Leopold's principle that the sole criterion for morality is preserving the "integrity, stability and beauty of the biotic community", this position asserts that sustainable hunting and animal agriculture are environmentally healthy and therefore good.
[77] Hinduism holds vegetarianism as an ideal for three reasons: the principle of nonviolence (ahimsa) applied to animals; the intention to offer only "pure" (vegetarian) or sattvic food to a deity and then to receive it back as prasad; and the conviction that an insentient diet is beneficial for a healthy body and mind and that non-vegetarian food is detrimental for the mind and for spiritual development.
While it is neither required nor prohibited for Jews to eat meat, a number of medieval scholars of Judaism, such as Joseph Albo and Isaac Arama, regard vegetarianism as a moral ideal.
Similarly, Islamic dietary laws permit the consumption of certain animals at the condition that their meat is not obtained through prohibited methods of slaughtering (ex: strangling, beaten to death, etc.
[82] The precise definition of a moral community is not simple, but Hsiao defines membership by the ability to know one's own good and that of other members, and to be able to grasp this in the abstract.
[87][88][89] Steven Davis, a professor of animal science at Oregon State University, argues that the least harm principle does not require giving up all meat.
[90] This conclusion has been criticized by Jason Gaverick Matheny (founder of in vitro meat organization New Harvest) because it calculates the number of animals killed per acre (instead of per consumer).
[93] One of the main differences between a vegan and a typical vegetarian diet is the avoidance of eggs, honey and dairy products such as milk, cheese, butter, and yogurt.
[100][101][102] In these systems and in free-range egg production, unwanted male chicks are culled and killed at birth during the process of securing a further generation of egg-laying hens.