There are two main moral issues concerning our dealings with animals (here by "animals" I mean non-human animals):

  1. Do animals belong in the moral sphere intrinsically or merely parasitically?
  2. If they belong to the sphere of morality intrinsically, how should we deal with them?

A.    Do animals belong in the moral sphere intrinsically?

Of course (some) animals belong within the moral sphere parasitically: they are someone's pets or property, and harming them is indirectly harming their owner.  However, here we are addressing a different issue: Do animals per se belong in the moral sphere?  Those who adopt a negative answer, e.g. Aquinas or Kant, embrace radical speciesism: Since animals don't fall within the purview of morality, we can do with them as we please; consequently, even trivial human interests take precedence over vital animal interests.

Arguments for Radical Speciesism:

Theological arguments:

Problem: it's hard to see the relevance of having or lacking an immortal soul to being a subject of morality or not. If anything, the lack of an immortal soul should make us more sympathetic to animals.

There is, of course, the broader problem of the Ďhistoricalí truth of Genesis.


Sentience arguments:


Personhood argument:

Humans are persons, animals aren't.  But only persons are within the sphere of morality.  Hence, animals are outside such sphere.
Itís unclear what the necessary and sufficient conditions for personhood are.There are two main views:


         Thereís good evidence that some animals satisfy (1).

         Even assuming that no animals satisfies (2), there are humans that fail to satisfy (2) as well.This would entail that some human beings are not persons.


Problem: Many, perhaps all, non-human mammals satisfy (1)-(5).One could object than animals cannot reason, but that is ridiculously false. Crows (!) can solve complex problems involving abstraction; chimps have a political system involving alliances, medicate themselves, and have cultures.


Hence, it looks as if the strong version of personhood leaves out too many humans, and the weak version lets in some animals. 

A further problem is that itís difficult to argue that only persons belong in the moral sphere.

Thought Question: Can you think of some arguments?


Arguments against Radical Speciesism:

NOTE: This can go very far.For example, since 1999 in New Zealand apes cannot be used in testing, research, and teaching except in their own interest.



Some of those who find Radical Speciesism unacceptable and ill argued favor

Mild Speciesism

Animals cannot be moral agents (they're unable to engage in moral reasoning), and consequently, although they do belong in the moral sphere, the morally relevant differences between them and humans are wide enough to justify very unequal moral treatment.
Problem: Some of the criticisms that affect Radical Speciesism (e.g., comatose humans, infants) affect Mild Speciesism as well.


For Mild Speciesism, when trivial human interest and substantial animal interest are in conflict, we should choose the latter.  However, when they are comparable (e.g. equal or not largely different), we should give preference to human interests.For example, we should conduct animal experiments to find cures for human diseases but nor to produce a new shampoo.

Thought Question: Do you find Mild Speciesism attractive?Why?Why not?


B.  If animals intrinsically belong in the moral sphere, how should we deal with them?
This question can be broken down into three others:

                   I.            is it prima facie wrong to kill animals, however painlessly (imagine zapping them out of existence, as it were)?

                II.            is industrial animal farming wrong?

             III.            Is animal experimentation wrong?


I.    Is it prima facie permissible to kill animals painlessly?

Thought Question: Do you think that only persons have a claim to life?


II.    Industrial animal farming

Before considering industrial animal farming and animal experimentation, it may be helpful to make a few points about the Animal Welfare Act, the federal law protecting animals.  The original AWA was enacted in 1966, and revised six times after that

A. Some facts about industrial animal farming:

 B.  Considerations about industrial animal farming

Problem: one might argue that given the gulf between humans and animals, animal pain/pleasure is incomparable to human pain/pleasure.
Notice that one ought to specify 1) what the "gulf" consists in, and 2) why it is relevant to the evaluation of pain/pleasure.

Problem: Maybe not; itís unclear that much of the food people eat is good for them.At any rate, vegetarianism is medically viable and probably healthier than the average American diet.

Problem: Itís a non-sequitur. Animals are amoral, and consequently their behavior cannot be a guide for what we do.

Problem: Itís a non-sequitur.Even assuming that itís natural for us to prey on animals, it doesnít follow that we may be cruel to them.

 III.    Animals in the laboratory

A. Some facts about the use of animals in US laboratories:
In the US, between 18 and 23 million animals are used in laboratory research every year.The AWA offers little protection. Some examples may suffice. These two infamous experiments were carried out after the AWA was passed (1966), and  involved Rhesus monkeys, primates explicitly covered by the law.

  1. The US armed Forces Radiobiology Institute trained rhesus monkeys to run inside a wheel by giving them an electric shock if they slowed down.  Then, they were given a lethal dose of radiation.  While sick, vomiting, and defecating (these are effects of radiation) they were compelled to run until they dropped.  The alleged reason for the experiment was to see for how long irradiated soldiers could keep on fighting (Carol Frantz, "Effects of Mixed Neutron-Gamma Total-body Irradiation on Physical Activity performance of Rhesus Monkeys", Radiation Research  vol. 10 (1985), pp. 434-41)
    NOTE: because of military secrecy, it's almost impossible for the public to know what the US military does to animals.


  1. At the Primate Research Center in Madison, Wisconsin, rhesus monkeys were raised under conditions of maternal deprivation, so that when placed among normal monkeys, they would sit in a corner in a state of depression and fear.  Harlow and Suomi put female rhesus in a small steel cages a few hours after their birth and left them there in total isolation for 18 months.  Then, the monkeys were impregnated with what they called a "rape rack," and after giving birth, let loose on their own offspring.  Some paid no attention to their offspring; others crushed their skulls or "smashed the infant's face on the floor, then rub[bed] it back and forth."  The rationale for the experiment was to study the psychopathology of maternal rejection in humans.  Harlow and Suomi explained how baby rhesus are similar to, but smarter than, baby humans; how maternal love is equally important in both; how normal rhesus mothers show affection to their offspring, etc. (Harlow and Soumi, "Induced Psychopathology in Monkeys", Engineering and Science, vol. 33 (1970), pp. 9-14)

B. Analysis:
Here are some relevant considerations:

NOTE: Mild speciesism is much less egalitarian then Utilitarianism: in cases of equal, or even comparable, amount of animal and human pain, we should choose the former.Still inflicting pain to produce a new shampoo or detergent would not be permissible.