Moral Issues in Sexuality

Lesson Transcript
Instructor: Jessica Whittemore

Jessica has taught junior high history and college seminar courses. She has an M.A in instructional education.

Historically, the 'traditional view' behind the morality of sex has been that only sex between a married heterosexual couple is morally right, but that is no longer a widespread belief. This lesson will discuss the moral issues surrounding sexuality and examine the philosophers who have contributed to the debate around these issues. Updated: 01/03/2022

Famous Philosophers

Trying to have an objective conversation about the rights and wrongs of sex is sort of like trying to use a screen door on a submarine. Regardless of how hard you try, opinion is going to seep through. Keeping this in mind, today's lesson on the moral principles surrounding sexuality is going to be a tricky one. For this reason, we're going to do our best to limit our discussions to what some of the most famous moral philosophers of all time have to say on the sexuality subject. To be specific, we'll take a look at the opinions of Saint Thomas Aquinas, Immanuel Kant, Jeremy Bentham, Marquis de Sade, and Susan Brownmiller. As we do this, we'll break our discussion down into those who hold to the traditional view that only sex between a married man and woman is moral, and those who definitely don't.

Let's kick things off with our traditionalists, Aquinas and Kant.

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Ethical Implications of the Double Standard

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:00 Famous Philosophers
  • 0:50 Aquinas
  • 1:43 Kant
  • 3:05 Bentham
  • 4:05 Marquis de Sade
  • 5:00 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed


According to those who study the morality of sexuality, St. Thomas Aquinas is one of history's most famous defenders of traditional sexuality. As a 13th century philosopher, his views on sexuality have come to be known as the natural law theory.

Keeping things very simple, the natural law theory argues that God designed sex to be between a man and a woman. Speaking biologically, the penis is naturally designed to impregnate a woman, and the woman's anatomy is naturally designed to accept this impregnation. In short, God designed our sexual organs to procreate; therefore, any sexual activity that can't lead to procreation is immoral.

Aquinas also held to the belief that sex is meant for the marriage bed alone. After all, keeping sex within the confines of marriage is the only way to make sure that a man's children are really his children.


Of course, Aquinas isn't the only one who holds to this traditional view of marriage. He is joined by the famous 18th Century philosopher Immanuel Kant.

Taking a bit of a different route than Aquinas but coming to the same conclusion, Kant believed that sex is only moral when a man and a woman experience it in full devotion and respect for one another. In fact, one of the hallmarks of Kant's philosophy was that treating another human like an object is always immoral.

Now, since sexual desire is really about personal gratification, one could argue that it's difficult to treat the object of one's sexual desire as anything but that - an object. For this reason, Kant believes marriage, in which two people have committed their whole selves to one another, is the only way to mitigate the effects of sexuality's inborn selfishness.

Sounding very much like a mom talking to her teenager, Kant believed marriage is the only real hope for sex to be accompanied by real love and respect. To quote him directly, ''Matrimony is the only condition in which use can be made of one's sexuality. If one devotes one's person to another, one devotes not only sex but the whole person; the two cannot be separated.''

Okay, let's leave our 'traditional view of sexuality' philosophers for now and turn to a couple of those who have a different view: Bentham and Marquis de Sade.


Born in 1748, Jeremy Bentham was a famous British philosopher and social reformer. Going against the mainstream opinions of his time, Bentham held to the utilitarian view of sexuality. This view argues any sexual act is moral if its utility, or its usefulness, outweighs its negative impact. In simpler terms, a sexual act is moral as long as its positives outweigh its negatives.

What this means is that a blanket of right or wrong can't merely be thrown at sexual acts; instead, each situation needs to be looked at under the lens of utility. For instance, does the possibility of an unwanted pregnancy outweigh the utility of premarital sex? Does the possibility of destroying a family outweigh the utility of an extramarital affair? In short, sexual morality is never just black or white. It needs to be decided on a case-by-case basis.

Taking a step past the beliefs of Bentham, and a huge leap past the thoughts of Aquinas and Kant, we turn to the thoughts of the Marquis de Sade.

Marquis de Sade

Born in 1740, Marquis de Sade was a French philosopher made famous for not only his liberal views on sexuality but also his personal sexual exploits. In direct opposition to Aquinas' natural law theory of sexuality, de Sade believed nature has given man the greatest possible assortment of sexual freedoms.

To state it really simply, de Sade belonged to the 'no holds barred' school of sexual morality. In other words, if you want to, go ahead. According to de Sade, the laws of man, and not nature, are to blame for stifling sexuality. Be it homosexuality, adultery, or premarital, sex in any form is free from the charge of immorality. To quote him directly, albeit a bit graphically, ''Nature places no great importance on fluid, which runs through our loins, and it is not concerned if we prefer to direct it down one path or another.''

Now, let's take a look at Susan Brownmiller's thoughts on morality issues associated with sexual consent and sexual abuse within the confines of marriage.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it now
Create an account to start this course today
Used by over 30 million students worldwide
Create an account