Current criminal law in England and Wales does not recognize consent of the victim as a defence of deliberately killing others. Although in cases of terminal illness patients have the right to deny life-saving treatment or to request pain-killers even in fatal doses, it is an offence to deliberately act to end a person’s life in English law. A person’s consent does not serve as a defence in these cases of terminal illnesses, let alone killing for gratification. However, the right to consent to pain, injury or death always attracts interest as a result of a number of criminal trials which include consenting victims in a range of activities such as mercy killing, active euthanasia and cannibalism. Hence it is an ongoing debate whether consent or request of a victim should affect the criminal liability of the perpetrator, either by diminishing liability completely or by decreasing the degree of it. Historically, before the seventeenth century the ‘volenti non fit injuria (a person is not wronged by that to which she consents)’ maxim was valid, and so individuals were free to consent to almost anything. With the change in the system of punishment towards monopolization, the victim was no longer the central figure in the normative and centralised judicial structure. Inevitably, historically private offences turned into the public offences. As a result, consent of the victim lost its power in certain criminal acts which the state considers as damaging to itself. In this conventional conception of consent, when a perpetrator breaches the law she threatens the head of the state to define and guarantee the citizens’ rights. Currently, although there is a meaningful distinction between both consensual acts of mercy killing and killing for gratification, still as a matter of public policy, no one can consent to her own death. Putting paternalistic and subjective moral reasons such as the state or the public’s interest in prohibiting its citizens from harming themselves aside, as they may extend the scope of criminal law to an undesired level, an objective moral reason, namely ‘human dignity’ as in the Kant’s second formulation of the Categorical Imperative, can be argued to constitute a strong foundation for limiting personal autonomy. Dignity is an essential characteristic of all human beings, therefore a degrading conduct might be wrongful even if it does not violate the victim’s rights due to consent. In this respect, consent as an exercise of personal autonomy remains valid until the act crosses the boundaries of degrading human dignity to a serious degree. When the consenter’s dignity is violated, meaning when she is treated as a mere means to her end rather than as end in itself, consent loses its power as a justifying reason. From this point of view, confirming that harm is not only a violation of rights but also the violation of human dignity leads us to conclude that consent should always be at least partial defence, since it negates one part of harm, namely violation of rights. In this respect, considering active euthanasia or mercy killing as an act of respecting ones’ dignity and also not a violation of a person’s rights, these kinds of acts along with other strict conditions should not be subject to criminal liability at all. It can be said that even in these circumstances of respect, consent alone cannot serve as a defence for deliberate killing, therefore consent to being killed just for gratification should neither provide complete nor partial defence. English law embraces consent fully when absence of consent is an intrinsic and essential element of the offence, as in the example of rape, kidnapping or theft. However, for other offences involving physical harm, consent plays the role of defence only for limited number of cases, such as, actual bodily harm, lawful sports and medical treatment. Although legally and morally there is some difference between killing for mercy or active euthanasia (which is legal in some countries, but under strict conditions) and killing for gratification, in both cases consent by itself does not constitute a defence for criminal liability. However, consent not only represents a defence but is also a part of personal autonomy which is one of the foundations of the modern state. Therefore, there needs to be more explanation than bare legal prohibitions for not being able to consent for acts concerning one’s own body.