Volume II · Considering Sentient Beings · chapter 2
What Is the Argument from Species Overlap?
Before you read study layer, not part of the original text
If the lack of certain abilities and relationships in some humans doesn't justify treating them worse, the same lack in animals doesn't either; and it's usually a reason to care more, since it increases vulnerability.
There are babies and people who can't talk, can't reason like adults, or have no family. We don't stop caring for them because of that: we care even more. If that's how it is with these people, it should be the same with animals.
If a hospital treated a baby who can't talk but refused to treat an injured dog “because he can't talk,” it would be using a double standard.
- P1 The abilities and relationships used to exclude animals are not present in all humans.
- P2 Their absence in babies and in certain humans doesn't justify treating them worse.
- P3 If the absence of these traits doesn't justify treating humans worse, it doesn't justify treating animals worse either.
- C Therefore, these abilities and relationships don't justify disregarding animals.
The chapter’s central argument in logical form. If the premises are true, the conclusion follows. To disagree, you have to show which premise is false.
They say “But those humans are exceptions.”
Answer The argument doesn't depend on how many humans are in that situation: it's enough that they exist and that, rightly, we don't accept mistreating them. Species “overlap” when it comes to these abilities.
More objections and answers in Debunking objections.
Original text Luciano Carlos Cunha · Volume II, p. 12 of the PDF edition · English translation
The argument from species overlap, despite having a rather strange and complicated name, is an easy argument to understand. Moreover, it is one of the main arguments in defense of respect for nonhuman animals. It arises as a response to attempts to justify disregard for nonhuman animals that appeal to capacities or relationships. All of this will be explained in detail below.
It is often argued that what makes practices that cause suffering and death to nonhuman animals right, and also what makes it right not to give them the help they need, is the fact that nonhuman animals lack certain capacities or certain relationships.
For example, it is commonly said that nonhuman animals do not deserve the respect humans deserve because they lack complex cognitive capacities. At other times, it is said that it is right not to help animals because they are in no position to help us (that is, we have no relationships of mutual solidarity with them), or because they do not contribute to our society (that is, we have no political relationships with them). At yet other times, it is said that what makes it right to torture and kill animals is the simple fact that we have the power to do so and they have no power to defend themselves, being completely vulnerable.
The argument from 5 begins by observing that, whatever capacity or relationship is chosen as the criterion for excluding nonhuman animals from the sphere of (or for giving them lesser consideration), there will always be humans who do not possess it and who would therefore also be disadvantaged by such criteria.
This is the case, for example, of babies, children up to a certain age, and victims of certain diseases or accidents that prevent the development or exercise of those capacities and relationships. Such humans do not possess the complex cognitive capacities that adult humans typically possess. Also, unfortunately, many of them are not in relationships of mutual solidarity (on the contrary, they have been abandoned), and they are also in no position
to contribute to society. Moreover, they exercise power over no one (on the contrary, like nonhuman animals, they are completely vulnerable).
The argument from species overlap then observes that, if the lack of those capacities or relationships in these humans cannot justify treating them worse than normal adult humans - much less doing to them what is typically done to nonhuman animals - then the lack of those capacities or relationships in nonhuman animals could not justify treating them worse than normal adult humans either, much less justify the typical disregard they receive.
Moreover, the lack of those capacities and relationships in those humans is normally seen as a reason to give them even greater care, since it increases their vulnerability. Thus, the lack of those capacities and relationships in nonhuman animals is also a reason to give them greater care, and not a reason to treat them worse or to disregard them.
Practice
Study layer. The answers are based on the chapter’s text.
Why is the argument called “species overlap”?
According to the chapter, in humans, the lack of those abilities is usually seen as a reason to...
Food for thought
What traits would you use to separate those who can be exploited from those who can't? Would any human end up on the wrong side?
Author’s notes 1
Sources cited in this text 7
The full list for the volume is in the Volume II references.
- BENTHAM, J. Introduction to the principles of moral and legislation. Oxford: Oxford University Press, 1996 [1789].
- EHNERT, J. The argument from species overlap. Blacksburg: Virginia Polytechnic Institute and State University, 2002.
- HORTA. O. The Scope of the Argument from Species Overlap. Journal of Applied Philosophy, v. 31, p. 142-154, 2014.
- MILLER, H. B. A terminological proposal. Society for the Study of Ethics and Animals Newsletter, v. 30, 2002.
- PORFIRIO. Abstinence from animal food. London: Thomas Taylor, 1823 [ca. 280].
- SINGER, P. Ética Prática. São Paulo: Martins Fontes, 2002 [1979].
- WILSON, S. The Species-Norm Account of Human Status. Between the Species, v. 13, n. 5, 2005.
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