1. Animal Rights
Broad View - Animals have the same moral worth that humans have, and the moral obligations we have to animals are the same that we have to humans.
Narrow View - Animals have no moral worth, and we have no moral obligations to them.
Moderate View - Animals have moral worth, but it is less than the moral worth that humans have. We have moral obligations to animals, but these obligations are weaker than the obligations we have to humans.
Animal View - Animals have moral worth, but it is more than the moral worth that humans have. We have moral obligations to animals, and these obligations are stronger than the obligations we have to humans.

2. Narrow View R. D. Guthrie's Argument
1. How animals treat other animals is not a moral issue.
2. How animals treat humans is not a moral issue.
.: 3. How humans treat animals is not (inherently) a moral issue.
.: 4. Animals have no moral worth, and we have no moral obligations to them.

3. R. D. Guthrie Mistreating animals can still be morally wrong because:
Animals can be the property of person's who do have moral worth.
Animals can be instrumentally valuable in promoting human welfare.

4. R. D. Guthrie Limitations
Implies that it is morally permissible to mistreat unowned animals that are not instrumental in promoting human welfare.
Implies that it is morally permissible for animal owners to mistreat their own animals that are not instrumental in promoting human welfare.

5. R. D. Guthrie 1. How animals treat other animals is not a moral issue.
2. How animals treat people is not a moral issue.
.: 3. How people treat animals is not (inherently) a moral issue.
.: 4. Animals have no moral worth, and we have no moral obligations to them.

6. R. D. Guthrie
Objection
1. How infants treat other infants is not a moral issue.
2. How infants treat other humans is not a moral issue.
.: 3. How humans treat infants is not (inherently) a moral issue.
.: 4. Infants have no moral worth, and we have no moral obligations to them.

7. Narrow View Human Argument
1. Moral worth is a function of being human.
2. Only humans are human.
.: 3. Only humans have moral worth.
.: 4. Animals have no moral worth, and we have no moral obligations to them.

8. Moral Worth Is a Function of Being Human

9. Moral Worth Is a Function of Being Human

10. Moral Worth Is a Function of Being Human

11. Moral Worth Is a Function of Being Human

12. Peter Singer
"Pain and suffering are bad and should be prevented or minimized, irrespective of the race, sex or species of the being that suffers....Pains of the same intensity and duration are equally bad, whether felt by humans or animals."

13. Peter Singer
Racism - Favoring the interests of one being over another solely on the basis of a difference in race.
Sexism - Favoring the interests of one being over another solely on the basis of a difference in sex.
Speciesism - Favoring the interests of one being over another solely on the basis of a difference in species.

14. Human Argument Limitations Implies speciesism.
Implies that "higher" beings, such as God, angels, and Martians, have no moral worth.
Implies that it is morally permissible to abuse or torture animals for the mere fun of it.

15. Moderate View Capacities Argument
1. Moral worth is a function of a being's capacity for intelligence, rationality, self awareness, suffering, and moral reasoning.
2. Some animals have these capacities but humans have these capacities to a greater extent.
.: 3. Some animals have moral worth, but it is less than the moral worth that humans have.
.: 4. We have moral obligations to some animals, but these obligations are weaker than the obligations we have to humans

16. Capacities Argument Advantages Does not imply speciesism.
Does not imply that "higher" beings, such as God, angels, and Martians, have no moral worth.
Does not imply that it is morally permissible to abuse or torture animals for the mere fun of it.
Does not imply that we should be morally indifferent between driving over a mouse and driving over a child.

17. Moral Worth

18. Moral Worth
What is morally special about a being's capacity for intelligence, rationality, self awareness, suffering, and moral reasoning rather than its leaping ability, sense of smell, and capacity to bark?

19. Moral Worth

20. Moral Worth

21. Moral Worth

22. Moral Worth

23. Capacities Argument
1. Moral worth is a function of a being's capacity for intelligence, rationality, self awareness, suffering, and moral reasoning.
2. Some animals have these capacities but humans have these capacities to a greater extent.
.: 3. Some animals have moral worth, but it is less than the moral worth that humans have.
.: 4. We have moral obligations to some animals, but these obligations are weaker than the obligations we have to humans.

24. Capacities Argument Limitations
It is not clear why moral worth should be a function of a being's capacity for intelligence, rationality, self awareness, suffering, and moral reasoning, as opposed to some other set of characteristics.
If moral worth is a function of a being's capacity for intelligence, rationality, self awareness, suffering, and moral reasoning, not all humans have these characteristics to a greater extent in comparison to all other animals.

25. Moderate View
Animals have moral worth, but it is less than the moral worth that humans have. We have moral obligations to animals, but these obligations are weaker than the obligations we have to humans.

26. Moderate View Objection
1. The Moderate View is correct only if there is a set of characteristics that all humans have to a greater degree in relation to all other animals.
2. There is no set of characteristics that all humans have to a greater degree in relation to all other animals.
.: 3. The Moderate View is not correct.

27. Animal Rights
Broad View - Animals have the same moral worth that humans have, and the moral obligations we have to animals are the same that we have to humans.
Narrow View - Animals have no moral worth, and we have no moral obligations to them.
Moderate View - Animals have moral worth, but it is less than the moral worth that humans have. We have moral obligations to animals, but these obligations are weaker than the obligations we have to humans.

28. Animal Rights
What is the moral status of (nonhuman) animals and what moral obligations do we have to them?

29. Animal Rights
Any plausible account of the characteristics that determine moral worth will have the consequence that some but not all humans have these characteristics to a greater extent in comparison to some animals.

30. Moderate Animal View
Some humans have greater moral worth compared to some animals, and some animals have greater moral worth compared to some humans. In some cases the moral obligations we have to some animals is weaker than the moral obligations we have to some humans, and in some cases the moral obligations are greater.

31. Animal Rights

32. Animal Rights

33. Animal Rights