In this paper it is argued that the experimental data on commissurotomy patients provide no grounds for denying the singular personhood of commissurotomy patients. This is because, contrary to most philosophical accounts, there is no “unity of consciousness” discriminating condition for singular personhood that is violated in the case of commissurotomy patients, and because no contradictions arise when singular personhood is ascribed to commissurotomy patients.

First, I introduce the concept of a “non-agential subject,” where a non-agential subject exists within an organism and has phenomenally conscious experiences in a morally significant way, but is not morally responsible for the organism's voluntary actions. Second, I argue that it's a live possibility that typical adult humans contain non-agential subjects. Finally, I argue that, if there are non-agential subjects, this has important and surprising implications for a variety of ethical issues. Accordingly, ethicists should pay more attention to whether (...) there are non-agential subjects and what their implications for ethics would be. (shrink)