Hilary Yancey

This dissertation investigates the metaphysics of human body parts; particularly, the epistemic conditions under which something can be said to be a “body part of” some particular human being. In this dissertation I draw on the hylomorphism of Aristotle and John Duns Scotus to argue that a necessary and sufficient condition on human bodily parthood is an object’s functioning for the sake of the whole human being and the maintenance of her biological life. I argue that, on this view of bodily parthood, at least some prostheses or artificial organs are truly body parts of the human beings in whom they operate. I defend this view in reference to both Aristotelian and Scotistic hylomorphism, as well as answering objections raised by some contemporary views of bodily parthood as merely conventional. I argue that this has important implications for medical ethics, including potentially restricting medical interventions in end-of-life care and heightening the legal ramification of damage done to prostheses. I argue that investigation into the metaphysical questions surrounding body parts and their composition can illuminate hitherto underappreciated dimensions of ethical questions in medicine.

In this paper I argue for a Thomistic alternative to Martha Nussbaum’s justice for animals as outlined in Frontiers of Justice. I argue that an account of analogous justice between humans and animals can generate real and robust obligations towards animals. I first show how Aquinas’s treatment of nonhuman animals in the questions on law evince a wider, shared community between humans and animals by which we see animals and humans as equally under divine providence. I then argue that while Aquinas’s definition of justice excludes animals in its proper sense, his treatment of animals in questions such as those on theft and charity prove that there is room to understand at least an analogous or metaphorical sense by which we can see them as recipients of justice. Finally, I examine Nussbaum’s own account and illustrate key similarities between her view and that of Aquinas.

It is widely agreed that first-person testimony is a good source of evidence, including testimony about the contents of mental states unobservable to others. Thus we generally think that an individual’s testimony is a good source of evidence about her wellbeing—after all, she experiences her quality of life and we don’t. However, some have argued that the first-person testimony of disabled individuals regarding their wellbeing is defeated: regardless of someone’s claim about how disability affects her overall wellbeing, other evidence about disability undermines the force of her testimony with respect to our justified beliefs. In this paper, I argue that at least some cases of first-person testimony about disability is not defeated. Particularly, neither the existence of conflicting testimony nor evidence about disabilities’ associated harms or challenges successfully undermine either the content of the testimony or the reliability of the testifiers. While I do not claim that first-person testimony is the only evidence relevant to characterizing disability, I argue that it is not always blocked by other evidence about disability. At least some first-person testimony from disabled individuals is, therefore, undefeated evidence relevant to evaluating disability and overall wellbeing.