Martha Nussbaum and the Foundations of Ethics: Identity, Morality and Thought-Experiments

Martha Nussbaum has argued in support of the view (supposedly that of Aristotle) that we can, through thought-experiments involving personal identity, find an objective foundation for moral thought without having to appeal to any authority independent of morality. I compare the thought-experiment from Plato’s Philebus that she presents as an example to other thought-experiments involving identity in the literature and argue that this reveals a tension between the sources of authority which Nussbaum invokes for her thought-experiment. I also argue that each of her sources of authority presents further difficulties for her project. Finally, I argue that it is not clear that her thought-experiment is one that actually involves identity in any crucial way. As a result, the case she offers does not offer any satisfactory support for her view on the relation between identity, morality and thought-experiments, but we do gain some insights into what that relation really is along the way.