Moral risk and communicating consent

[Excerpt] An agent's rights restrict how it is permissible for others to act. The fact that a mug is yours prohibits me from taking it, but you can give me permission to borrow it, and if you do, you make it the case that I would not wrong you (nor trespass your rights) were I to borrow the mug. There are many considerations other than your consent which could make it all-things-considered permissible for me to borrow your mug, for instance, if doing so were necessary to save someone's life and would only mildly inconvenience you. But when the only consideration bearing on whether I may borrow the mug is whether you allow me to do so, I require a consent-based permission. If I lack such a permission, taking the mug would trespass your property rights, wronging you. So, if I need a mug and you want to let me borrow yours, it is important that you be able to let me know that you have given me permission.

In everyday discussions, the term “consent” can be used in a wide array of ways. It isn't clear that all these uses track a single phenomenon, and even if they do, we might reasonably worry that our social practices regarding consent are defective, not perfectly corresponding to the moral profile of consent. So, this article is not concerned with everything we call “consent”; it is instead wholly focused on understanding what is necessary for issuing genuine moral consent-based permissions. Much of the philosophical and legal attention given to this question focuses on a few high-stakes contexts: consent to sex, to medical procedures, or to legally binding contracts. These are some consent-based permissions, but there are also more mundane cases, such as agreeing to swap seats on a flight, inviting someone onto your property, or purchasing a coffee, and a good account of consent should be serviceable in these domains as well.