[Title missing] : on the metaphysics and ethics of omissions.

In this dissertation, I argue for a general analysis of omissions and then apply that analysis to an issue in medical ethics. One omits when they don’t act in a particular way, can act in that way, the action was required for some further activity, and one is already (in some sense) engaged in that further activity. I argue, contrary to contemporary analyses, that omissions are inherently normative, in the sense that the action not done was necessary for some good to be achieved. I then apply this analysis of omissions to medical futility, which is when a medical intervention cannot benefit a patient. I argue that we should understand “benefit” as the goods that the patient can seek or that physicians can provide. I then interpret medical futility as practical impossibility, whereby benefitting the patient is impossible, either because it physically cannot succeed or because it would fail to prioritize the relevant goods. Where a treatment cannot benefit the patient, it is futile, and therefore one is not obligated to seek it. In other words, refusing or withdrawing futile treatment does not constitute killing by omission.