I. Introduction Sexual activity requires consent, which is defined as positive, unambiguous, and voluntary agreement to engage in specific sexual activity throughout a sexual encounter. Consent cannot be inferred from the absence of a “no”; a clear “yes,” verbal or otherwise, is necessary. While a decade ago, affirmative consent definitions were rare, nowadays they feature in the campus codes of over 1,400 universities in the United States. One of the most striking recent developments in sexual offence policy has been the proliferation of affirmative consent policies. These policies vary in their details but share the common theme of prohibiting sexual activity with someone who has not acted in a way that expresses their consent. Yale University's is a representative example:While a decade ago, affirmative consent definitions were rare, nowadays they feature in the campus codes of over 1,400 universities in the United States. 1 However, the criminal law has mostly bucked this trend. In the United States, a few states' rape law does include an affirmative consent definition, and one was considered in the ongoing revisions to the American Law Institute's Model Penal Code. 2 But these revisions ended up defining consent in terms of someone's willingness to engage in sexual activity. 3 On that definition, someone's communicative behavior is relevant only as evidence about what they are willing to do. If…potential defendants are punished in order to cause social change or to protect women by creating prophylactic rules, then we are punishing individuals who are nonculpable as to what we really care about (nonconsensual sex) in order to accomplish our goal (better and more accurate communication about consent). We are punishing the morally innocent. We should pause before punishing the innocent for the collective good.6 But the Mental View of consent is not the only game in town. Its rival is the “Behavioral View,” according to which someone gives valid consent only if they have indicated with behavior that they have chosen to permit the action in question. Insofar as affirmative consent policies have received philosophical attention in print, this has occurred in the context of a longer standing debate about what is required for morally valid consent. 4 In a formidable critique of these policies, Kimberly Ferzan has defended the “Mental View” that valid consent requires only an inner mental choice or intention. 5 According to this view, so long as uncommunicative sexual partners have made these choices, each would act permissibly. But an encounter without communication would be a sexual offence according to affirmative consent policies, and this concerns Ferzan:But the Mental View of consent is not the only game in town. Its rival is the “Behavioral View,” according to which someone gives valid consent only if they have indicated with behavior that they have chosen to permit the action in question. 7 On that view, encounters without clear communication would be morally impermissible, and in previous work, I have provided a partial defense of affirmative consent policies on these grounds. 8 So far, the debate over affirmative consent policies is yet to explore the possibility that these policies might have a rationale that is acceptable to adherents of both the Mental View and the Behavioral View. In this essay, I articulate this independent rationale: each of us has a “Duty of Due Diligence” to take adequate measures to investigate whether our sexual partners are willing to engage in sexual activity. But on the assumption that someone had adequate evidence that their partner is willing to have sex only if their partner has clearly expressed this willingness, the Duty of Due Diligence would imply that affirmative consent policies need only be sanctioning behavior that is wrong in itself: the policies would sanction people who have wrongfully failed to ascertain that their partners are willing to engage in sexual activity. As long as these policies' sanctions for this behavior are suitably proportionate to its wrongfulness, this provides a defense of these policies wherever that assumption holds. But by reflecting on the exceptions where the assumption does not hold, the Duty of Due Diligence suggests an alternative way of formulating sexual offence policies to achieve goals of affirmative consent policies: these policies could simply codify an institutional analogue of the Duty of Due Diligence itself. In other words, these policies could directly sanction someone for engaging in sexual activity without adequately investigating that their partner was willing to engage in this activity. As proponents of the Mental View can accept that we each have the Duty of Due Diligence, I intend to remain neutral on the debate between that view and the Behavioral View. In other words, I do not aim to resolve here what morally valid consent is. Also, as my interest concerns which actions should be prohibited by laws and codes, I intend to remain neutral on the orthogonal question of what constitutes culpability for the purposes of punishing someone who engages in prohibited behavior. Everyone agrees that someone can be culpable in virtue of knowingly engaging in this behavior or in virtue of recklessly being aware that they are taking an excessive risk of engaging in this behavior. But controversy breaks out over when, if at all, it is appropriate to punish someone who does wrong negligently. Roughly, someone does wrong negligently when they are unaware that there is at least a significant risk that they are acting impermissibly, but they ought to have been aware of this risk.9 While most people have the intuition that we can at least sometimes be culpable for acting negligently, some argue that this intuition misleads. For example, on the grounds that culpability always requires a choice to take risks, Larry Alexander and Ferzan argue that “culpability‐based criminal law will not include liability for negligence.”10 Even among the majority who believe that some forms of negligence ground culpability, there is further debate about which forms of negligence do.11 Personally, I am sympathetic to the claim that someone can be culpable for committing an offense out of ignorance that results from their failing to take due care to ensure that they do not commit this offense. If that claim is right, then culpably violating the Duty of Due Diligence could make someone culpably negligent for engaging in nonconsensual sex. But I will not insist on this claim, as it is unnecessary for my central argument. Even if it turned out that only knowledge or recklessness are grounds of culpability, someone could still be appropriately punished for knowingly or recklessly failing to carry out the Duty of Due Diligence.

II. Affirmative Consent Let us start by looking more closely at the details of affirmative consent policies, using the previously quoted policy of Yale as our guide. It contains a characteristic feature of an affirmative consent policy, namely that consent cannot be inferred from the mere fact that someone is not expressly refusing sex. (“Consent cannot be inferred from the absence of a ‘no’.”) Instead, someone must actively indicate their willingness to have sex. Yale's policy is flexible in one respect about the form that this behavior may take, as it flags that the behavior need not be verbal. As a result, body language, gestures, or actions could count as ways by which we communicate consent. That is a sensible feature of the policy, given that we communicate nonverbally in various contexts. We frown to show that we disagree with someone's proposal, and we shuffle along a public transport seat to indicate that we are happy for another passenger to sit next to us. But there is also a respect in which the policy is demanding: it requires that this communication be clear or unambiguous. So if someone mumbled or if they could reasonably be interpreted in more than one way, then there would be no consent according to the policy. Affirmative consent polices can be seen as the latest instances of a progressive trend away from the idea that victims have responsibilities to resist sexual assault. Against the historical backdrop of policies that implied that no offence had been committed unless a victim resisted—and polices that recognized an offence only when a victim “resisted to the utmost”—affirmative consent policies take the stance that a victim does not even have to indicate that they are unwilling to have sex. Instead, the default is always that it is impermissible to make sexual contact with someone, unless that person has clearly indicated that it is permissible. Unexpressed. A and B are both willing for B to sexually penetrate A. However, A and B are inexperienced and nervous and so they do not attempt to communicate that they are both willing. While B thinks that, most likely, A is willing for B to penetrate A, B is not fully confident about this. However, B is apprehensive about asking, and worried that doing so will indicate inexperience. Moreover, B assumes that A will expressly refuse if A is unwilling. B penetrates A. If this interaction occurred on Yale's campus, then the campus code would imply that B has made sexual contact without A's consent, even though A was willing for the sexual encounter to take place. Of course, A's willingness may make it the case that A is less likely to make a complaint. But if the relationship between A and B took a turn for the worse, then A would be within their rights to make this complaint. Similarly, as Yale's code requires unambiguous communication, it implies that an offence has also been committed in a case like this: Ambiguity. C attempts to communicate that they are willing for D to sexually penetrate C. But because C is inexperienced and nervous, C's attempts to communicate are ambiguous. While D thinks that, most likely, C is willing for D to penetrate C, D is not fully confident about this. However, D is apprehensive about asking, and worried that doing so will indicate inexperience. Moreover, D assumes that C will refuse if C is unwilling. D penetrates C. As C has failed to communicate unambiguously, Yale's policy implies that D lacks C's sexual consent, despite C having attempted to communicate their willingness for the sexual activity to take place. But in trying to protect individuals' sexual autonomy, affirmative consent policies catch in their wake mutually welcome encounters like the following:If this interaction occurred on Yale's campus, then the campus code would imply that B has made sexual contact without A's consent, even though A was willing for the sexual encounter to take place. Of course, A's willingness may make it the case that A is less likely to make a complaint. But if the relationship between A and B took a turn for the worse, then A would be within their rights to make this complaint. Similarly, as Yale's code requires unambiguous communication, it implies that an offence has also been committed in a case like this:As C has failed to communicate unambiguously, Yale's policy implies that D lacks C's sexual consent, despite C having attempted to communicate their willingness for the sexual activity to take place. Unexpressed and Ambiguity cases, but in a case like this: Unwilling. E is willing to engage in minor sexual activity with F, but is unwilling for F to penetrate E. But because E is inexperienced and nervous, E does not express to F the types of sexual activity that E is willing to take part in. While F thinks that, most likely, E is willing for F to penetrate E, F is not fully confident about this. However, F is apprehensive about asking, and worried that doing so will indicate inexperience. Moreover, F assumes that E will refuse if E is unwilling. F penetrates E. In this case, E is subject to sexual penetration against their will. This is a gross violation of their personal autonomy, and will no doubt also be a distressing experience that leads to serious psychological harm. These implications call into question affirmative consent policies, as these cases do not seem to involve serious sexual assault. Yet, sexual consent policies' gravitas derives from their role in preventing and sanctioning sexual assaults. A paradigm of such an assault is not exemplified in theandcases, but in a case like this:In this case, E is subject to sexual penetration against their will. This is a gross violation of their personal autonomy, and will no doubt also be a distressing experience that leads to serious psychological harm. By contrasting the Unwilling case with the Ambiguity and Unexpressed case, I aim to make a point about which types of sexual offence, if any, have been committed. It is worth stressing that these points do not concern the agent's culpability for their behavior. As the cases are sketched, B, D, and F all have a similar epistemic situation. As an agent's culpability depends on her epistemic situation, it may be that each agent is culpable to the same degree. But it does not follow that the conduct of each is morally equivalent. F has penetrated E against E's will, while neither B nor D has penetrated anyone against their will. Penetrating someone against their will is a distinctively serious wrong. We would miss this feature if we evaluated each agent's conduct purely from their own evidential situation. This evaluation would miss the differing effects on the victim, and these effects bear on the extent to which the victim is wronged. So the Unwilling case exemplifies the most serious forms of sexual offence. But to sanction a sexual offence in the Unwilling case, an affirmative consent policy is not necessary. Because E is not willing for F to penetrate E, we can explain the wrong of F's conduct in terms of E's mental states. For example, the proposed revisions to the Model Penal Code would deem this interaction nonconsensual in light of the absence of E's “willingness to engage in a specific act of sexual penetration or sexual contact.”12 So the worry that affirmative consent policies are overly broad would be compounded by a worry that these policies are unnecessary to sanction serious sexual assaults.

III. The Duty of Due Diligence Even those of us who are broadly supportive of affirmative consent policies should acknowledge a central insight at the heart of this critique: there is a clear moral difference between the Unexpressed and Ambiguity cases, on the one hand, and the Unwilling case, on the other. Whatever we think of B's and D's behavior in the Unexpressed and Ambiguity cases, F commits a much more serious wrong in the Unwilling case. To deny this is to implausibly maintain that the seriousness of a wrong does not depend on the victim's attitudes toward the encounter, the victim's experience during the encounter, and the effects that the encounter has on the victim. We will return to this point later, but for now, let us note that if a wrong has been committed in the Unexpressed and Ambiguity cases, then it is not the most serious type of sexual offense, and any policy's sanctions should reflect this. This point is well taken, but it does not by itself show that an affirmative consent policy is unjustifiable on the grounds that the policy sanctions morally permissible behavior. There remains the possibility that B and D have still committed a more minor offence.13 Indeed, I will argue that this is the case. I suggest that we should be perturbed by how B and D act in these cases—we would hope that no one we cared about acted in this way, or was in the position of A and C, for that matter. When we consider what is awry with each agent's conduct, the natural candidate is that the agent has proceeded without ascertaining that their partner is willing to have sex. While their partner has not clearly indicated that they are willing, the agent does not know that their partner consents. For B or D to know that A and C are willing to engage in sexual activity, A and C would need to express this willingness through behavior. In turn, each consent‐receiver's failure to ascertain that their partner is willing suggests that the consent‐receiver is not acting in a way that expresses a sufficient concern with whether their partner is willing. If the consent‐receiver acted in a way that expressed more concern, then they would have made greater efforts to establish whether their partner is willing to have sex. Following this line of a thought, we should conclude that the consent‐receiver has acted impermissibly by failing to express proper concern for the other person's authority over their personal boundaries. To develop this idea, let us start with the big picture thought that responsible moral agency does not just involve acting in ways that we believe are morally permissible. It also involves aiming at forming accurate beliefs about which actions are morally permissible. This would plausibly involve thinking a priori about what morality requires of us, as well as empirically investigating the effects of our actions. That big picture thought applies to everything we morally ought to do. So if we have a duty to preserve the Great Barrier Reef for the sake of its intrinsic value, then we ought to consider whether our actions contribute to coral‐bleaching. This impersonal investigative duty would not be owed to anyone in particular. However, when our actions affect other people, we do not just have an impersonal investigative duty to discover what we ought to do. We also have specific investigative duties owed to these individuals. If your action might harm Jane or infringe her rights, then you owe it to Jane to gather evidence about whether your action does so. More generally, for every duty we have to respect another person's rights, we have a correlative duty to investigate whether our action would respect their rights. This is not just to say that someone who had failed to carry out these investigations would have a bad character. It is also to say that these investigations are required of them. If they asked us whether to investigate the moral status of their actions, then we would advise them that they ought to do so, and if they seemed reluctant, then we would demand that they did. Defendants can inflict two kinds of wrongful harms upon victims of offences of non‐consent: the primary harm of subjecting them to conduct without their having subjectively and voluntarily chosen it for themselves; and the lesser, dignitary harm of manifesting a readiness or willingness to subject them to that primary harm.14 In this context, a dignitary harm is the harm of being treated disrespectfully—in a way that subjects the victim to an indignity. While Westen focuses on a dignitary harm of manifesting a willingness to subject someone to nonconsensual activity, the dignitary harm would plausibly also be inflicted by an agent who acts as though they are willing to subject this person to nonconsensual activity. Duty of Due Diligence If X needs Y's consent to perform action A, then X has a duty of due diligence owed to Y regarding X's performance of A. X avoids breaching this duty if and only if Either (i) X refrains from performing A; Or (ii) X has adequately investigated that Y has decided that they are willing for X to perform A I include the qualification “regarding X's performance of A” to acknowledge that there may be other ways that X could disrespect Y by failing to take due care toward Y. We can apply this idea to consent. Suppose an agent is considering whether to perform an action for which they need another person's consent. The agent would have an investigative duty to ascertain whether the other person is consenting. The agent also ought to find out what the other person is consenting to. A plausible ground of this duty is that its breach is a form of disrespect. As Peter Westen puts the point,In this context, a dignitary harm is the harm of being treated disrespectfully—in a way that subjects the victim to an indignity. While Westen focuses on a dignitary harm of manifesting a willingness to subject someone to nonconsensual activity, the dignitary harm would plausibly also be inflicted by an agent who acts as though they are willing to subject this person to nonconsensual activity. 15 Now if an agent fails to investigate properly whether a partner is willing to engage in this activity, then the agent would be acting as though they are willing to subject this person to nonconsensual activity. So this agent would have a duty to investigate, assuming that the agent plans on performing the action for which the consent is required. If instead the agent chooses to walk away and do nothing, then they would have no duty to investigate whether the other person is consenting. So the investigative duty has a disjunctive form: it requires either inaction or investigation. To capture this idea, we should formulate the duty along the following lines:I include the qualification “regarding X's performance of A” to acknowledge that there may be other ways that X could disrespect Y by failing to take due care toward Y. 16 Perhaps, there is room for further debate about the details of how the principle should be formulated. But the central idea is that for any action for which someone's consent is required, the principle gives the relevant agent a Duty of Due Diligence. The agent breaches this duty by performing the action without having adequately investigated whether the person is willing for them to perform this action. The phrase “adequately investigated” is deliberately vague, in light of the fact that the appropriate forms of investigation will be context‐sensitive. This would depend on whether we are dealing with “low stakes” consent, such as consent to minor uses of each other's property, or “high stakes” consent, such as invasive medical surgery. What counts as adequate investigation would also depend on the costs of investigating. Suppose an agent has good evidence about whether the other person is consenting. If it will be onerous for her to investigate further, then she may count as having adequately investigated the matter. But if further investigation were costless, then the agent would need to carry it out. Defenders of the Mental View of consent can posit the Duty of Due Diligence. Like the Behavioral View, the Mental View only concerns what it takes for someone to give valid consent that releases someone from a primary duty not to interfere with another's person or property. By contrast, the Duty of Due Diligence is a secondary duty governing the steps that someone should take to ensure that they are complying with the primary duty. One could hold that valid consent is mental, and still hold that we have a further duty to adequately investigate that the other person has the requisite mental states. Indeed, if anything, positing the Duty of Due Diligence helps the Mental View in the debate with the Behavioral View in the following respect. In that debate, the Behavioral View is sometimes motivated on the grounds that consent must be public to provide the consent‐receiver with epistemic access to the consent.17 But this motivation is undermined by positing the Duty of Due Diligence. If the consent‐receiver complied with this duty, then this compliance would improve their epistemic access to the consent. So insofar as we think it a virtue of a set of normative principles governing consent that these principles make it more likely that all parties have common knowledge of whether each is willing to permit an encounter, this can be realized by including the Duty of Due Diligence within this set, without embracing the Behavioral View. Let me clarify my proposal by comparing it with a different idea. I noted at the outset that in addressing which actions should be prohibited by laws or codes, I am remaining neutral on the controversy over what it takes for someone to be culpable for performing a prohibited action. Engaging in that controversy, some people have argued that if an agent unreasonably believes that their partner consents to sex, then the agent can be appropriately punished for sexual assault. Their proposal is motivated by a concern for cases like Unwilling, in which F commits the sexual offence of penetrating E against their will, while believing that E is willing. The proposal would be that if F holds this belief in E's consent negligently, then F is culpable for the sexual offence and may be punished. While this argument resonates with many people's intuitions, it depends on a controversial view of culpability. As we saw, some philosophers deny that negligence is an appropriate ground of culpability for punishment.18 We need not take any stance on this controversy when endorsing the Duty of Due Diligence as a duty that we owe to each other. By endorsing this duty, we are taking a stance on when someone has behaved in a morally acceptable way, and when their behavior is morally impermissible. As the permissibility of an action is distinct from the agent's culpability for performing this action, we are not thereby taking a stance on when someone is behavior is culpable. As a result, the Duty of Due Diligence is acceptable even to theorists who take a narrow view of culpability, as grounded only in either knowledge or recklessness.

IV. A New Foundation for Affirmative Consent Policies Let us take stock. We noted that affirmative consent policies imply that offences have been committed in the Unexpressed and Ambiguity cases. So we looked for plausible wrongs committed by the relevant agents, and this led us to posit the Duty of Due Diligence. Because these agents infringe that duty, affirmative consent policies would be sanctioning wrongdoers in the Unexpressed and Ambiguity cases. Does that mean we have reached a normative foundation for these policies? Distraction. Anya emails her friend Brittney to ask if she can borrow Brittney's car for the rest of the day. Brittney thinks that this is fine with her. But before Brittney can write an email in response, she gets distracted by a commotion in her office. While Brittney is attending to the commotion, Camila sneakily writes an email response from Brittney's account, saying that it is fine to use the car, and signs it “Brittney.” Anya reads that email and borrows the car. Brittney has decided to consent to Anya's action. In addition, Anya has carried out her Duty of Due Diligence, by adequately investigating whether Brittney is willing for her to take the car. Anya has a justified belief that Brittney has indicated that she is happy for Anya to use the car. However, Brittney has not indicated that she is willing for Anya to use the car, because she was distracted before she could do so. This shows that a consent‐giver's expressive behavior is not necessary for a consent‐receiver to discharge their Duty of Due Diligence. It does not. Carrying out the Duty of Due Diligence does not require expressive behavior on the part of the consent‐giver. Consider the following case:Brittney has decided to consent to Anya's action. In addition, Anya has carried out her Duty of Due Diligence, by adequately investigating whether Brittney is willing for her to take the car. Anya has a justified belief that Brittney has indicated that she is happy for Anya to use the car. However, Brittney has not indicated that she is willing for Anya to use the car, because she was distracted before she could do so. This shows that a consent‐giver's expressive behavior is not necessary for a consent‐receiver to discharge their Duty of Due Diligence. Even so, this result holds because of special features of the Distraction case. This case involves consent to the use of impersonal property. There are at least two distinctive features of this type of consent. First, this is a fairly low‐stakes type of consent. Second, a consent‐giver may use the property at distance from the consent‐receiver. Together, these features make it appropriate for the consent‐receiver to investigate the other person's willingness through email. Email's considerable convenience outweighs its slight unreliability. Requiring Anya to visit Brittney at the office or even to give her a call would be over the top. And even those methods might not foil Camila if she were Brittney's identical twin, or able to impersonate Brittney's voice… Contrast this with sexual consent. In a sexual encounter, an agent is in close proximity to their partner, and so at least typically an agent's adequate investigation could not be complete without their sexual partner engaging in communicative behavior that was clear in the circumstances. Here, it is relevant that sexual consent is a paradigm of high‐stakes consent, and this feature increases the investigatory burden on sexual partners to establish each other's willingness to have sex. This burden should be understood in terms of the type of evidence that they are required to seek. The agent would need to have found clear and unambiguous evidence of their partner's willingness to have sex. In addition, as Jennifer Lackey has argued, the agent would need to receive this evidence from first‐hand testimony from their partner; relying on third‐parties' testimony would be inappropriate, given the stakes involved.19 This is not to deny an evidentiary role for background circumstances. After all, every piece of communicative behavior is dependent for its meaning on the context in which it takes place. Even an utterance of “I want to have sex with you right now!” can only express sexual consent because of the background conventions that govern the English language. Moreover, the appropriate interpretation of implicit or nonverbal behavior is sensitive to the relationship between the communicants as well as their prior interactions with each other. For example, if two men have recently met on a smartphone app that is exclusively used for facilitating casual sexual encounters, then that evidence will bear on how to interpret their subsequent communications with each other. Similarly, if it is “a central tenet of your religion that sex should take place only in the context of a marriage, which you have embraced since childhood, and you frequently speak about how your religious beliefs are central to your identity as a person,” then this would bear on how to interpret whether you are consenting to sex with any particular utterance.20 In general, discharging one's Duty of Due Diligence requires taking into account all the available evidence, including background context. While the importance of sexual consent counts toward increasing the investigatory burden, this burden also has to take into account the costs of investigating. Some critics of affirmative consent policies object that these policies would usher in a drab sexual culture, in which sexual encounters have lost their spontaneity and thrill. The merits of this criticism are debatable, however. On the one hand, these costs seem relatively minor when compared to the costs of mistakes. Moreover, to the extent that someone has competent social skills, and can adeptly interpret and signal verbal and nonverbal cues, this person will be able to find out whether their partner is willing to have sex with them, without ruining the moment. The costs of awkwardness are born by those who have not developed these social skills, yet it is precisely these people who are most at risk of making mistakes about whether their partners are consenting. For them, there is more to be said for erring on the side of caution rather than excitement (and we might speculate that novices' sexual encounters are often going to involve a certain amount of awkwardness anyway). As such, concerns about unexciting sexual encounters give us little reason to deny that adequate investigation would involve taking reasonable steps to assure oneself to a high degree that one's sexual partner is consenting. Investigation/Expression Assumption. When engaging in a sexual encounter, a consent‐receiver discharges their duty of due diligence only if the consent‐giver has positively and unambiguously indicated that they agree to engage in this encounter throughout its duration. A consent‐receiver has not adequately investigated this agreement if they are relying only on an absence of a “no.” That assumption is deliberately formulated in the language of Yale University's policy to show how the assumption, in combination with the Duty of Due Diligence, would ensure that the policy only prohibited wrongful behavior. What this suggests is that much of the time an assumption like the following would hold:That assumption is deliberately formulated in the language of Yale University's policy to show how the assumption, in combination with the Duty of Due Diligence, would ensure that the policy only prohibited wrongful behavior.

V. Two Revisions to Affirmative Consent Policies The foregoing constitutes a defense for implementing affirmative consent policies like Yale's in cases where the Investigation/Expression Assumption holds. But our discussion suggests two possible revisions that we might like to make to these policies. The first possible revision concerns the fact that it is questionable whether the Investigation/Expression Assumption does hold universally. The most plausible counterexamples are sexual encounters within the context of established long‐term relationships. Suppose, two spouses have negotiated an understanding that one person will explicitly object to sexual contact if they are unwilling to engage in it. This person is an assertive and confident member of groups that are privileged in terms of social power, and there is a solid bedrock of trust between the spouses. Would their partner be carrying out their Duty of Due Diligence by being guided by their omitting to articulate an unwillingness to engage in sex? We might be in two minds about this question. On the one hand, we might feel some pull toward thinking that as there is a chance that any agent is uncharacteristically reticent, their partner's due diligence always requires looking for unambiguous behavior that indicates their willingness to engage in a specific encounter. That thought would lead to discomfort with the idea that one can ever responsibly infer this willingness from an omission. On the other hand, there is a countervailing pull toward thinking that there are versions of this case in which the partner could know what this person was thinking in light of their omission. But if it really is true that they know that their sexual partner is willing to permit and engage in the sexual encounter, then it would seem that no further investigation is required. Sexual activity requires consent, which is defined as unambiguous and voluntary agreement to engage in specific sexual activity throughout a sexual encounter. Then, the policy could add the following guidance on how to interpret the definition when applying it in practice: In nearly all cases—including all sexual activity between individuals who are not regular sexual partners, and all sexual activity between individuals who are partially intoxicated—this willingness cannot be inferred from the absence of a “no”; a clear “yes,” verbal or otherwise, is necessary. As consent is defined in terms of unambiguous agreement, this definition allows that the married couple can consent in virtue of an omission, so long as in the circumstances that omission constitutes unambiguous agreement to engage in sex. Still, if a policy used this definition to prohibit nonconsensual sexual activity, then the policy would be restrictive enough to penalize individuals who relied on inadequate evidence. Further, the guidance explicitly states that relying on an absence of refusal is insufficient in casual hook‐ups—the types of interaction that concern proponents of affirmative consent policies. Let us suppose for the sake of argument that in cases like these, one partner could know of the other's willingness because of their omission. This creates a problem for appealing to the Duty of Due Diligence to support an affirmative consent policy like Yale's. As Yale's policy does not recognize omission as constituting communication, and the policy is part of a general code that applies to sex within established relationships as well as casual hook‐ups, the policy would prohibit the encounter if it happened on campus. If the encounter is not wrong, then the policy looks overly broad. Here is one way to narrow it. The policy could define consent as follows:Then, the policy could add the following guidance on how to interpret the definition when applying it in practice:As consent is defined in terms of unambiguous agreement, this definition allows that the married couple can consent in virtue of an omission, so long as in the circumstances that omission constitutes unambiguous agreement to engage in sex. Still, if a policy used this definition to prohibit nonconsensual sexual activity, then the policy would be restrictive enough to penalize individuals who relied on inadequate evidence. Further, the guidance explicitly states that relying on an absence of refusal is insufficient in casual hook‐ups—the types of interaction that concern proponents of affirmative consent policies. sexual activity without due care. An actor is guilty of “sexual activity without due care,” if the actor knowingly engages in sexual activity with someone, without adequately investigating that this person is willing to engage in this sexual activity. The actor's investigation is adequate only when it is unambiguous that this person agrees to engage in this specific sexual activity. Again, this definition can be supplemented with guidance: In nearly all cases—including all sexual activity between individuals who are not regular sexual partners, and all sexual activity between individuals who are partially intoxicated—this agreement cannot be inferred from the absence of a “no”; a clear “yes,” verbal or otherwise, is necessary.21 As that offense does not mention sexual consent, the policy would be reframing an affirmative consent policy as a policy requiring due care in sexual relations. The second possible revision concerns the language with which the policy is phrased. Extant affirmative consent policies frame sexual offences in terms of the absence of affirmative consent. But if a campus code aims to sanction people who depart from the Duty of Due Diligence, then the code could simply codify that duty itself:Again, this definition can be supplemented with guidance:As that offense does not mention sexual consent, the policy would be reframing an affirmative consent policy as a policy requiring due care in sexual relations. At this point, someone might object that we are no longer defending affirmative consent policies: we have simply changed the subject, and we are now proposing alternative policies that sanction a lack of due care in sexual relations. In response to this objection, I agree that a switch to sexual activity without due care would at least amount to reframing extant affirmative consent policies. All the same, there remain important similarities in terms of the type of conduct required by the extant and revised policies. Like Yale University's policy, sexual activity without due care requires that it must be unambiguous that one's partner agrees to engage in sexual activity. Also, the guidance makes clear that this at least typically requires a clear “yes,” verbal or otherwise. Do these similarities mean that we continue to categorize sexual activity without due care as an “affirmative consent policy”? Or do the dissimilarities mean that we should consider it only a descendant of affirmative consent policies? I find it hard to believe that much hangs on which answer we give. The key substantive question is how to frame a sexual offence policy so that it prohibits behavior that is morally wrong. In response to that question, I am offering sexual activity without due care as a candidate for a policy that can be defended on the grounds that it prohibits behavior that is morally wrong in virtue of violating the Duty of Due Diligence.