William Gildea

The main aim of the thesis is to reject the idea that there is a hierarchy of moral status among humans and animals and to offer a new understanding of human and animal equality in its place. Here’s the central puzzle that motivates the thesis. Humans seem more morally important than animals. Most philosophers explain this intuition by citing certain advanced mental properties that humans tend to have and animals lack. But this view relegates any human without these properties to a lower moral status, creating fundamental inequalities among humans. We can defend human equality by rejecting hierarchies of moral status, which involves embracing animal equality. But this causes another problem. Philosophers who defend animal equality fail to explain why it is compatible with the powerful intuition that some of our basic duties to humans are stronger than our basic duties to animals. I offer a solution to this unsolved puzzle. I develop a new non-hierarchical view. According to this view, humans and animals have equal moral status, but this equality does not imply that they are equals in other moral or political domains. I argue that our basic duties to moral equals can differ in strength. This account rescues two intuitions which other views fail to bring together. First, humans are equal. Second, the duty not to kill human beings is almost always stronger than the duty not to kill animals. I also offer a new view of what grounds moral status. Against personism, modal personism and sentience-only views, I argue that humans and animals matter in virtue of their sentience and two other basic mental capacities, including very minimal mental continuity over time. I end by drawing out the implications of my account for the question of how societies should respond to commercial meat production.

The main aim of the thesis is to reject the idea that there is a hierarchy of moral status among humans and animals and to offer a new understanding of human and animal equality in its place. Here’s the central puzzle that motivates the thesis. Humans seem more morally important than animals. Most philosophers explain this intuition by citing certain advanced mental properties that humans tend to have and animals lack. But this view relegates any human without these properties to a lower moral status, creating fundamental inequalities among humans. We can defend human equality by rejecting hierarchies of moral status, which involves embracing animal equality. But this causes another problem. Philosophers who defend animal equality fail to explain why it is compatible with the powerful intuition that some of our basic duties to humans are stronger than our basic duties to animals. I offer a solution to this unsolved puzzle. I develop a new non-hierarchical view. According to this view, humans and animals have equal moral status, but this equality does not imply that they are equals in other moral or political domains. I argue that our basic duties to moral equals can differ in strength. This account rescues two intuitions which other views fail to bring together. First, humans are equal. Second, the duty not to kill human beings is almost always stronger than the duty not to kill animals. I also offer a new view of what grounds moral status. Against personism, modal personism and sentience-only views, I argue that humans and animals matter in virtue of their sentience and two other basic mental capacities, including very minimal mental continuity over time. I end by drawing out the implications of my account for the question of how societies should respond to commercial meat production.

Philosophers struggle to explain why human beings with deep cognitive impairments have a higher moral status than certain non-human animals. Modal personism promises to solve this problem. It claims that humans who lack the capacities of “personhood” and the potential to develop them nonetheless could have been persons. I argue that modal personism has poor prospects because it's hard to see how we could offer a plausible account of modal personhood. I search for an adequate understanding of modal personhood by considering existing accounts and sketching new ones. But each account fails, either because it objectionably excludes some deeply cognitively impaired humans from the class of modal persons or because it makes modal personhood doubtfully relevant to moral status. And the modal personist cannot solve this problem by appealing to the misfortune suffered by modal persons.