This thesis is comprised of four substantive essays on consent. More specifically, they concern individual permissive consent—that is to say, consent by which one person intentionally and directly gives another person moral or legal permission to perform an action. What follows is a brief outline of each of those essays. Essay One is titled ‘An Introduction to the Importance of Consentin Our Sex Lives’. In this essay, I explore three themes. The first is whether consent is necessary or sufficient for morally permissible sex. The second theme is how someone’s consent relates to whether that person is wronged or harmed by another person having sex with them. The third theme concerns how all this relates to the principles that govern the legitimate scope of the criminal law. Essay Two is titled ‘Conditional Consent’. In this essay, I distinguish two ways for someone to place conditions on their morally valid consent. The first is to place conditions on the moral scope of their consent—whereby they waive some moral claim rights but not others. The second is to conditionally token consent—whereby the condition affects whether they waive any moral claim rights at all. I suggest that understanding this distinction helps makes progress with debates about so-called ‘conditional consent’ to sexual intercourse in English law, and with understanding how individuals place conditions on their morally valid consent in other contexts. Essay Three is titled ‘Sexual Consent and Having Sex Together’. In this essay, I defend what I call the Commonsense View of sexual consent. The Commonsense View states that if you have sex with someone without that person’s consent, you thereby infringe that person’s moral rights. Perhaps surprisingly, John Gardner, Catharine MacKinnon, and Tanya Palmer all deny the Commonsense View. According to their view, if sex is in some sense ideal, then each partner’s consent is unnecessary—that is to say, even absent each partner’s consent, neither partner infringes the other’s moral rights. On the contrary, I defend the Commonsense View. In so doing, I develop what I call the Hybrid Account of Consent. The Hybrid Account retains the benefits of two existing accounts of consent while avoiding their shortcomings. I close by suggesting some benefits of my alternative picture and some implications for law reform. Essay Four is titled ‘Children, the Unconscious, and the Dead: Consent and the Will Theory of Rights’. In this essay, I defend the Will Theory of Moral and Legal Rights from what I call the Impossibility Objection. The Impossibility Objection alleges that if the Will Theory is correct, then it is impossible for children, the unconscious, and the dead to have moral and legal rights. I formulate a version of the Will Theory, and use insights about the timing of consent to argue that this version can avoid the Impossibility Objection. This leaves the Will Theory with better extensional adequacy than is widely supposed to be possible. The four substantive essays are followed by a brief chapter titled ‘Summary and Directions for Future Research’.