Discrimination takes many forms. Discrimination occurs when someone is given less moral consideration than others or treated worse for an unjustified reason.1 There is discrimination against certain human beings based on their sex, skin color, sexual preference, and for many other reasons.

Speciesism is discrimination against members of other species. More formally, speciesism means giving sentient beings of different species differing moral consideration for unjust reasons. This could be treating all nonhuman animals worse than humans, or it could be treating the animals of some species worse than animals of other species. For example, in many cultures, dogs are treated better than chickens.

Discrimination is unjustified differential moral consideration

When we give someone moral consideration, it simply means we take into account how they will be affected by our actions and omissions, attitudes and decisions. Moral consideration need not apply only to sentient (conscious) beings. Some people give moral consideration to things such as ecosystems or species, though generally moral consideration is only given to conscious beings. We can, and do, give greater or lesser moral consideration to some beings than others.

In the following links the arguments against speciesism briefly presented here are explained in more detail:

Arguments against speciesism

The argument from species overlap

The argument from relevance

The argument from impartiality

Begging the question

Moral intuitions and biases

For defenses of speciesism, see:

Defenses of speciesism

Discrimination and exploitation

Those facing discrimination are often exploited. It is possible to discriminate against others but still treat them well. However, it is still discrimination to treat someone less well than we treat others for arbitrary, and therefore unjust, reasons, such as skin color or sex.

Speciesism is a form of discrimination – discrimination against those who don’t belong to a certain species. In most human societies, it is considered completely normal to discriminate against animals of other species. The ways this discrimination occurs and its severity differ from place to place, and certain animals are treated worse in some places than others. For example, dogs, cows, and dolphins are regarded very differently in some societies than in others. One thing most societies have in common is that they discriminate in some very harmful ways against at least some species of animals.

Speciesism is so commonplace that most people don’t think to question it except in cases where the type or degree of discrimination is unusual in their culture. As a result, humans exploit nonhuman animals in the course of everyday life, using them as resources. This happens in a variety of ways. Nonhuman animals are consumed as food, used for clothing, tormented and killed for entertainment, exploited for work, and raised and killed so their body parts can be used as raw materials in cosmetics and other consumer products. They are, essentially, slaves.

Even when animals are not exploited, they are still the victims of speciesism. They are discriminated against because they are not taken into serious consideration.2 Humans have a variety of attitudes towards animals. There are some who don’t treat animals with any respect at all. A minority of people don’t have any concern for the way animals are treated and are not concerned even when animals are tortured pointlessly. A less extreme version of this view is shown by people who are opposed to torturing animals in some unusual ways or merely for the fun of it, yet don’t think it matters very much that animals suffer because of the way humans treat them as long as humans benefit from it.

There are others who treat animals with some respect, but still discriminate against them and arbitrarily treat them worse because they are not members of the human species. The same thing can be seen in racist attitudes: one can be against human slavery but still be racist.3

It’s generally thought that only human beings deserve full moral consideration, which amounts to speciesism. Often, it is considered acceptable to harm an animal if it will bring some benefit to humans – no matter how small. And even though it’s considered a good thing to help humans who need help, when a nonhuman animal needs help they are often left to their fate. This happens in particular in the case of nonhuman animals living in nature.

One does not have to hate or want to harm someone in order to discriminate against them, nor is it necessary to have a sadistic character.4 Discrimination against nonhuman animals is simply a matter of not giving importance to the harms or benefits that may come to them as a consequence of our behavior towards them, when we would take such harms and benefits towards humans into consideration. Additionally, certain animals are discriminated against not in comparison to human beings, but in comparison to other nonhuman animals. For example, one can have more respect for dogs than pigs, or for mammals than other animals, even in situations where the less respected animals will be harmed as a result. For example, one can reject the use of dogs and cats for food (an acceptable practice in some countries) but accept the consumption of, say, chickens and fishes.5 This is also a form of speciesist discrimination, since all sentient animals have an interest in not being harmed regardless of the species to which they belong.

A common form of speciesism that often goes unnoticed is the discrimination against very small animals. In general, we have a psychological disposition to care less about small animals. Many people consider a horse much more deserving of consideration than, for example, a mouse, simply because of their relative sizes.6 We have a tendency to think that smaller animals are less conscious, but this is not necessarily so.

Can we justify speciesism?

These days, racism and sexism are still defended by some people. However, many of us reject them as arbitrary discrimination. The question is: how can we oppose racism and sexism but accept speciesism?7

None of the reasons given to defend speciesism can really justify it. Sometimes it is maintained that we can discriminate against nonhuman animals simply because they are not human. But this is merely a biological circumstance, such as being born one sex or another, or with a certain skin color. It is completely arbitrary, and cannot justify discrimination. Sometimes it’s said that humans feel more sympathy for other humans than for nonhuman animals. But this isn’t a reason that justifies discrimination against nonhuman animals, either. Xenophobic and racist people feel more sympathy for certain humans than others. But that does not justify their attitude.

Others claim that we can discriminate against other animals because their intelligence is not like human intelligence. But this does not account for the fact that many humans don’t have the same type or degree of intelligence. Small children and those who are cognitively disabled, for example, don’t have what we usually think of when we think of “human intelligence.” Fortunately, most people are opposed to discrimination against humans on these grounds. But if intelligence cannot be a reason to justify treating some humans worse than others, it cannot be a reason to justify treating nonhuman animals worse than humans either.

When it comes to respecting others, what we should take into account is their capacity to have positive and negative experiences, such as enjoyment, satisfaction, and suffering. Therefore, if nonhuman animals can experience suffering and enjoyment, we should respect them and try not to harm them. To deny them respect because they don’t belong to our species, or because they don’t have intelligence similar to our own, is arbitrary discrimination. If we are truly impartial, we will reject all discrimination, including that based on species.

Why do the great majority of humans either ignore or defend discrimination against nonhuman animals? The reasons are simple. First, we have been taught since childhood to believe that animals of other species are inferior beings that don’t deserve much consideration. Second, we benefit from the exploitation of nonhuman animals, particularly in consuming their bodies and fluids as foods. Therefore we have little incentive to challenge these beliefs. Our beliefs make it seem acceptable to exploit other animals, and the benefits we derive from their exploitation motivate our beliefs. It’s convenient to accept the received wisdom that other animals are inferior and to accept this as something “obvious.” But such a view cannot be justified.

Further readings

Albersmeier, F. (2021) “Speciesism and speciescentrism”, Ethical Theory and Moral Practice, 24, pp. 511-527.

Arneson, R. J. (1999) “What, if anything, renders all humans morally equal”, in Jamieson, D. (ed.) Singer and his critics, Oxford: Blackwell, pp. 103-128.

Bernstein, M. H. (1998) On moral considerability: An essay on who morally matters, Oxford: Oxford University Press.

Bernstein, M. H (2015) The moral equality of humans and animals, Basingstoke: Palgrave MacMillan.

Bruers, S. (2013) “Speciesism as a moral heuristic”, Philosophia, 41, pp. 489-501.

Bruers, S. (2014) Born Free and Equal? On the Ethical Consistency of Animal Equality, Gent: LAP Lambert Academic Publishing.

Caviola, L.; Everett, J. A. & Faber, N. S. (2019) “The moral standing of animals: Towards a psychology of speciesism”, Journal of Personality and Social Psychology, 116, pp. 1011-1029.

Cushing, S. (2003) “Against ‘humanism’: Speciesism, personhood and preference”, Journal of Social Philosophy, 34, pp. 556-571.

DeGrazia, D. (1996) Taking animals seriously: Mental life and moral status, Cambridge: Cambridge University Press.

Everett, J. A.; Caviola, L.; Savulescu, J. & Faber, N. S. (2019) “Speciesism, generalized prejudice, and perceptions of prejudiced others”, Group Processes & Intergroup Relations, 22, pp. 785-803.

Faria, C. & Paez, E. (2014) “Anthropocentrism and speciesism: Conceptual and normative issues”, Revista de Bioética y Derecho, 32, pp. 95-103 [accessed on 23 January 2016].

Gompertz, L. (1992 [1824]) Moral inquiries on the situation of man and of brutes, London: Open Gate.

Horta, O. (2010) “What is speciesism?”, Journal of Agricultural and Environmental Ethics, 23, pp. 243-266 [accessed on 28 June 2013].

Horta, O. (2017) “Why the concept of moral status should be abandoned”, Ethical theory and moral practice, 20, pp. 899-910.

Horta, O. & Albersmeier, F. (2020) “Defining speciesism”, Philosophy Compass, 15, pp. 1-9.

Jaquet, F. (2021) “A debunking argument against speciesism”, Synthese, 198, pp.1011-1027.

Jaquet, F. (2022) “Speciesism and tribalism: Embarrassing origins”, Philosophical Studies, 179, pp. 933-954.

Kaufman, F. (1998) “Speciesism and the argument from misfortune”, Journal of Applied Philosophy, 15, pp. 155-163.

LaFollette, H. & Shanks, N. (1996) “The origin of speciesism”, Philosophy, 71, pp. 41-61.

Persson, I. (1993) “A basis for (interspecies) equality”, in Cavalieri, P. & Singer, P. (eds.) The Great Ape Project, New York: St. Martin’s Press, pp. 183-193.

Pluhar, E. (1996) Beyond prejudice: The moral significance of human and nonhuman animals, Durham: Duke University Press.

Regan, T. (1979) “An examination and defense of one argument concerning animal rights”, Inquiry, 22, pp. 189-219.

Ryder, R. D. (2011) Speciesism, painism and happiness: A morality for the twenty-first century, Exeter: Imprint Academic, pp. 38-61.

Sapontzis, S. F. (1987) Morals, reason, and animals, Philadelphia: Temple University Press.

Sapontzis, S. F. (1990) “The meaning of speciesism and the forms of animal suffering”, Behavioral and Brain Sciences, 13, pp. 35-36.

Singer, P. (2009 [1975]) Animal liberation, Reissue ed., New York: Harper Perennial Modern Classics.

Vallentyne, P. (2005) “Of mice and men: Equality and animals”, Journal of Ethics, 9, pp. 403-433.

Wilson, S. D. (2005) “The species-norm account of moral status”, Between the Species, 13 (5) [accessed on 27 August 2012].


1 See Boxill, B. R. (1991) “Equality, discrimination and preferential treatment”, in Singer, P. (ed.) Companion to ethics, Oxford: Blackwell, pp. 333-343; Horta, O. (2010) “Discrimination in terms of moral exclusion”, Theoria: Swedish Journal of Philosophy, 76, pp. 346-364 [accessed on 15 February 2014]; Lippert-Rasmussen, K. (2006) “Private discrimination: A prioritarian, desert-accommodating account”, San Diego Law Review, 43, pp. 817-856; Lippert-Rasmussen, K. (2007) “Discrimination”, in Ryberg, J.; Petersen, T. S. & Wolf, C. (eds.) New waves in applied ethics, Basingstoke: Palgrave Macmillan, pp. 51-72; Wasserman, D. (1998) “Discrimination, concept of”, in Chadwick, R. (ed.) Encyclopedia of applied ethics, San Diego: Academic Press, pp. 805-814.

2 An example of a position which is contrary to animal exploitation but defends speciesism can be found in this book: Zamir, T. (2007) Ethics and the beast: A speciesist argument for animal rights, Princeton: Princeton University Press.

3 See on this Graft, D. (1997) “Against strong speciesism”, Journal of Applied Philosophy, 14, pp. 107-118; Holland, A. J. (1984) “On behalf of moderate speciesism”, Journal of Applied Philosophy, 20, pp. 281-291.

4 Mason, J. (1998) “Misothery”, in Bekoff, M. & Meaney, C. A. (eds.) Encyclopedia of animal rights and animal welfare, Chicago: Fitzroy Dearborn, p. 245.

5 See on this Burgess-Jackson, K. (1998) “Doing right by our animal companions”, Journal of Ethics, 2, pp. 159-185.

6 See Morton, D. B. (1998) “Sizeism”, in Bekoff, M. & Meaney, C. (eds.) Encyclopedia of animal rights and animal welfare, op. cit., p. 318.

7 A comparison between speciesism and racism can be found in Patterson, C. (2002) Eternal Treblinka: Our treatment of animals and the Holocaust, New York: Lantern; Sztybel, D. (2006) “Can the treatment of animals be compared to the Holocaust?”, Journal of Agricultural and Environmental Ethics, 11, pp. 97-132. A comparison between racist and speciesist slavery, can be found in Spiegel, M. (1988) The dreaded comparison: Human and animal slavery, London: Heretic Books.