I Ought, Therefore I Can Obey

According to typical ought-implies-can principles, if you have an obligation to vaccinate me tomorrow, then you can vaccinate me tomorrow. Such principles are uninformative about conditional obligations: what if you only have an obligation to vaccinate me tomorrow if you synthesize a vaccine today? Then maybe you cannot vaccinate me tomorrow (e.g., because you cannot synthesize a vaccine); what you can do instead, I propose, is make it the case that the conditional obligation is not violated (i.e., that you do not both synthesize a vaccine today and fail to vaccinate me tomorrow). More generally, I propose the ought-implies-can-obey principle: an agent has an obligation only at times at which the agent can obey the obligation (i.e., can make it the case that the obligation is not violated). I also propose another principle, which captures the idea that ‘ought’ implies ‘can avoid’. I defend both principles mainly by arguing that they help explain why agents lose (i.e., stop having) obligations, including conditional ones.