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Magazine • Thinking it Through

The Moral Logic of Sexual Consent

The “Weinstein Effect,” and Oprah Winfrey’s recent denunciation of sexual predation in Hollywood, have provided us all with an opportunity to think through the role of consent in establishing the morality of sexual acts. Last month we looked at reasons why consent, by itself, is not enough.

These news stories give us reason to wonder why consent is even necessary for establishing the moral permissibility of sexual activity. Or, to put it negatively, why is sexual coercion wrong?

When we think through these questions, we discover that the implicit moral standard by which our secular culture judges sexual coercion to be immoral is the same standard that condemns those sexual acts that our culture thinks are morally acceptable: fornication, contraception, masturbation, and sexual activity between members of the same sex. 

But since people normally don’t articulate the moral theory that underlies their condemnation of sexual coercion, it needs to be teased out.

Free agents

Perhaps the very first thing that we notice about ourselves as human beings is that we’re free. Unlike an arrow that is moved to its target by an archer, and unlike an animal that is directed entirely by instincts, we have a power by which we’re able to freely move ourselves to an end (see Summa Theologiae I-II:1:2). As one philosopher puts it, we are “natural born end-choosers.”[1]  

This power, called free will, follows upon our power of reason. When we act, we act based on a judgment that something should be pursued or avoided. And, as St. Thomas Aquinas points out, “because this judgment . . . is not from a natural instinct, but from some act of comparison in the reason,” we act from “free judgment and retain the power of being inclined to various things” (ST, I:83:1; emphasis added).

Our self-determining power, therefore, is due to our nature as rational beings. And it’s this rational part of our nature that separates human beings from all other creatures in the material world.

Herein lies the reason why unjust coercion,[2] and in particular sexual coercion, is immoral: to unjustly impede someone from self-determination is to violate a person’s human dignity. It sees a person’s humanity as an evil to be avoided and thus reduces a person to something lower than a human: a tool, an object for use.

Following upon Aquinas’s teaching (II Sent. D. 44, q. 1, a 3, ad 1), Pope St. John Paul II, as Karol Wojtyla, unequivocally asserted the immorality of using a person as a mere means: 

Anyone who treats a person as the means to an end does violence to the very essence of the other, to what constitutes its natural right (Love and Responsibility, 26-27; emphasis added).

In light of this, it shouldn’t be hard to see why sexual coercion is immoral. It directs a person to an end that he doesn’t consent to but should be free to consent to: namely, sexual activity. And since it’s a violation of a person’s human nature to unjustly direct him to an end that he doesn’t consent to, it follows that sexual coercion does violence to the nature of the person who is being coerced.

Nature’s norms

The traditional sexual moralist is very happy at this point. The discussion thus far brings to the fore his underlying moral theory: nature determines moral norms for human action. The argument that sex must be consensual is grounded in what a human being is—in particular, in the rational dimension of human nature, since it appeals to intellect and will.

But our human nature doesn’t involve only rationality. It also involves animality (bodily sensations, appetites, and emotions, etc.). This is why Aristotle, and those following him (like St. Thomas), defined a human being as a rational animal.

Since the subject of human morals is a human being, and since a human being by essence has both rationality and animality, it follows that the shape of human morals ought to be determined not only by the patterns that belong to the form of our rational life but also by the specific form of our animal life. And this is where our sexuality comes into play.

Our sexed bodies flow from the animal side of our nature. And if our animality participates in determining moral norms for human action, then our sexed bodies, along with what they’re designed for, ought to participate in determining moral norms as well.

We can look to the nature of our sexual powers to determine which sexual acts are immoral, just as we look to the nature of our free will to determine that unjust coercion is immoral. Unjust coercion, and in particular sexual coercion, does violence to the natural design of a person’s free will because it unjustly impedes the exercise of self-determination.

Similarly, the sexual acts that our secular culture deems morally permissible do violence to the natural design of our sexual powers.[3] Such acts militate against what our sexual powers are for: procreation (and the rearing of children). And inasmuch as they violate the good of procreation, they violate the unitive purpose of sex as well, since you can only have a loving union if you will what is good for the beloved.

There is hope after all for our sex-crazed culture. The appeal to our human nature, and in particular its rational part, to condemn sexual coercion opens wide the doors for the animal part of our nature, and in particular our sexed bodies, to also play a role in the moral evaluation of sexual behavior.

If our culture is going to embrace human nature when it comes to determining the moral status of sexual coercion, then to be consistent it must also embrace human nature when it comes to determining the moral status of fornication, contraception, masturbation, and sexual activity between members of the same sex.

For to reject nature when it comes to the latter behaviors is, in principle, to justify the rejection of nature with regard to the former. But, if you think it through, no reasonable person should want to consent to that!


[1] Scott Sullivan, An Introduction to Catholic Sexual Morality (2017).

[2] I speak of “unjust” coercion because I acknowledge that there are some cases where coercion is justified, such as in the case of parent-child relationships, self-defense, and criminal punishment by imprisonment and/or death. For a detailed study on the latter topic, see Edward Feser and Joseph M. Bessette, By Man Shall his Blood Be Shed: A Catholic Defense of Capital Punishment (San Francisco: Ignatius Press, 2017) and Steven Jensen, Good and Evil Actions: A Journey through Saint Thomas Aquinas (Washington, DC: The Catholic University of America Press, 2010).

[3] A critic might object to this parallel and say that if there can be undue violence to the natural design of free will, then why can’t there be undue violence to the natural design of our sexual powers, which would imply that there are cases of due violence? The answer is that our free will can contribute to or threaten the common good. Our sexual powers, on the other hand, are such that the ends to which nature directs them (procreation and unitive love) constitute the common good. So, to use our sexual powers in a way that frustrates the achievement of these ends ipso facto militates against the common good. It is metaphysically impossible to do violence to our sexual powers in a way that would preserve the common good. Therefore, there can be no due violence to the natural design of our sexual powers.  

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