What is morality?

At its core morality is concern with the well-being of others (specifically, those that may care about their own well-being).1 Where well-being is clear-cut, easily understood, and universally agreed upon, then morality in those cases is also clear-cut, easily understood and universally agreed upon (e.g., killing a happy person just for fun is clearly an act against their well-being and hence a moral crime if perpetrated by someone who is aware of that.).

Does sex impact the well-being of individuals?

Absolutely.

The well-being of an individual in relation to sexuality is complex, hence reasoning about morality around sexuality is also difficult. There may be exceptions to each of these points because individual well-being is somewhat individual (and especially when it comes to sex). Still, certain ideas seem to apply generally (for instance, moral obligation to look after offspring produced from sexual intercourse).

These are the basic moral concerns regarding heterosexual-couplings2:

  1. Sex is highly pleasurable for most (hence, in the majority of cases, the act tends to directly contribute to well-being).
  2. Coitus is the overwhelmingly dominant form of reproduction of our species. Even if people are divided on over-population concerns, almost everyone agrees that some level of reproduction of the species constitutes a moral good.
  3. The well-being of offspring potentially produced by such a coupling ought to be a prime consideration since such offspring are moral subjects themselves. Considerations around production of offspring include:
    • Children produced in monogamous or near-monogamous relationships will have greater access to resources both from parents and grandparents (the influence of grandparents on the success of homo sapiens is documented).
    • In most Western cultures, where lineage is uncertain, patriarchal and grand-parent involvement is less likely to occur to ill-effect.
      In any event, it seems straightforward to suggest that both men and women have a moral duty to nurture and provide for the offspring they produce, and long-term, monogamous coupling is the most straightforward way to satisfy that moral obligation (although one’s moral duty towards offspring may be discharged via other arrangements successfully, too—for instance single mothers by choice seem to be as successful in child-rearing as couples).
  4. Sexuality instigates hormones and emotional reactions related to attachment and bonding (can be a positive and negative depending on the relationship). (e.g., oxytocin).
  5. Sexuality within the context of a committed relationship is often described as being highly rewarding (can peruse r/sex for many anecdotes). Still, novel sexual arrangements may be viewed as rewarding by some, and sex within a committed relationship may also suffer its own challenges when one or both partners lose sexual motivation for a variety of reasons.
  6. Sexually transmitted diseases negatively impact a person’s well-being.
  7. Women typically have less access to resources but the difference in sexual appetite (on average) between men and women lead to sex as a female resource. Hence, there are genuine concerns with the exploitation of women for sex and sexual experience.
  8. Sex comes at a significantly higher potential cost for women in the event of a unwanted (or even wanted) pregnancy: an abortion comes at some cost (for all women with the physical/pharmaceutical procedure and the emotional toll experienced by some women). Pregnancy, labor, delivery, nursing, and raising the child fall primarily or entirely on the woman (so massive disparity in impact of pregnancy).
  9. Consent provides boundaries and structure among interactions between free agents, and hence is a fundamental cornerstone of moral sexual relationships. (e.g., The Ethics of Consent: Theory and Practice)
  10. The genetic and physical health of offspring (hence the general ban on incest).
  11. Because sexuality is fraught with serious moral implication and physical and psychological consequence, because children are still early in developing their abilities to make accurate temporal projections and cannot be considered full independent agents, and because they are incredibly vulnerable to pressure and persuasion from adults, sexual engagement between adults and children is almost universally considered morally wrong. Cultures draw lines of adulthood at somewhat different points, but sexual engagement between adults and teenagers implies the same kinds of issues so is also morally problematic (in Western culture, 18 years of age is often considered the age of consent).
  12. Mammals seem to be easily conditioned in their sexual expression (see rat death pheromone experiments), hence we probably have some obligation to engage in sexuality in ways that positively influence our future sexual behavior.
  13. Monogamy (or not) plays a role in our species survival.

Conclusions

The first two points by themselves seem to argue for unrestrained sex between consenting adults. The rest of the points generally argue in favor of thoughtful/restrained sexual expression, at least to some degree. Of course, how to weigh all these considerations is its own challenge, and different societies have managed these multitudinous moral concerns in sometimes vastly different ways (e.g., compare the Inis Beag with the Mangaians).

To some significant extent effective/semi-effective birth control methods swing the calculus of sexual morality towards giving/receiving pleasure and bonding for its own sake and away from concerns about offspring which have dominated moral considerations of sexuality in times past. Also, in general, where societies jointly care for offspring (i.e., paternity is of little concern because all children will be cared for) or where women can control their reproductive future (i.e., many modern Western societies), sexual expression seems more abundant and egalitarian (again suggesting that these moral considerations are under equilibrium-type pressure and moral optima may vary somewhat depending on social norms and constraints).


Originally posted as a comment here. I’ve modified it some for content and for standalone context.

  1. The description of morality I use above is normative (i.e., we should do certain things in order to maximize well-being of, and minimize harm to, conscious creatures). Other formulations of morality are descriptive (e.g. moral foundations theory), and one could easily examine sex from within that kind of context and it would still be rife with moral considerations. 

  2. Moral ramifications for homosexuality and autosexuality also exist, but this document focuses on the moral ramifications of heterosexual sex, which is arguably more intrinsically complex than the others.