In this paper I will examine two responses to the argument from marginal cases; the argument from kinds and the similarity argument. I will argue that these arguments are insufficient to show that all humans have moral status but no animals do. This does not prove that animals have moral status but it does shift the burden of proof onto those who want to maintain that all humans are morally considerable, but no animals are.

Many people face a problem about potentiality: their moral beliefs appear to dictate inconsistent views about the significance of the potentiality to become a healthy adult. Briefly, the problem arises as follows. Consider the following two claims. First, both human babies and cats have moral status, but harms to babies matter more, morally, than similar harms to cats. Second, early human embryos lack moral status. It appears that the first claim can only be true if human babies have more moral (...) status than cats. Among the properties that determine moral status, human babies have no properties other than their potentiality that could explain their having more moral status than cats. So human babies’ potentiality to become adult persons must explain their having more moral status than cats. But then potentiality must raise moral status generally. So early human embryos must have some moral status. It appears that the view that must underlie the first claim implies that the second claim is false. (shrink)

This title examines the fields of value theory, normative and applied ethics on the issue of killing animals. It addresses a number of questions: Can painless killing harm or benefit an animal and, if so, why and under what conditions? Can coming into existence harm or benefit an animal? Is killing animals morally acceptable? Should animals have the legal right to life? In addressing these questions, animal rights and animal welfare positions are articulated and debated by some of the foremost (...) thinkers on these issues, with a distinction made between rights-based and utilitarian approaches. (shrink)