[1] Christian denominations generally hold that sexual morality is defined by natural law, the Bible and tradition.
[6] The unity of a couple in marriage and procreation are key factors in Christian sexual ethics, particularly in the teachings of the Catholic Church.
Not until contemporary times has sex been thought of as something generally good in the history of western philosophy: "Plato denigrated it, arguing that it should lead to something higher or better (Phaedrus, Symposium), Aristotle barely mentioned it, and Christian philosophers condemned it.
The concept originates in Kant's moral philosophy, and many modern thinkers have used it to criticize and analyze a wide range of ethical issues related to sex, such as pornography.
He considers sex the only inclination that cannot satisfy the Categorical Imperative; in fact, sexual desire by its nature is objectifying and lends itself to the thing-like treatment of other persons.
Kant argues that in a marriage, which is "a relationship that is structured institutionally in ways that promote and, at least legally if not morally, guarantee mutual respect and regard",[10]: 225 objectification may be rendered harmless.
However, Kant does not distinguish between male and female sexuality, and his analysis does not consider social hierarchies or asymmetric formations of erotic desire in or outside of marriage.
Enthusiastic consent, as expressed in the slogan "Yes means yes", rather than marriage, is typically the focus of liberal sexual ethics.
The concept of consent being the primary arbiter of sexual ethics and morality has drawn criticism from both feminist and religious philosophies.
[7][21] The feminist position is that women's freedom of choice regarding sexuality takes precedence over family, community, state, and church.
In some countries, such as Saudi Arabia, Pakistan,[30] Afghanistan,[31][32] Iran,[32] Kuwait,[33] Maldives,[34] Morocco,[35] Oman,[36] Mauritania,[37] United Arab Emirates,[38][39] Sudan,[40] Yemen,[41] any form of sexual activity outside marriage is illegal.
According to his theory, this was the reason for the often unusual sexual ethics displayed by persons living in brothels, asylums, on board ships, or in prisons.
Today, the practice, especially in Western cultures, of polyamory or open marriage raises ethical or moral issues.
Child-parent incest is also seen as an abuse of a position of trust and power, in addition to the inability of a child to give consent.
In addition, laws exist against this kind of abuse of power by priests, preachers, teachers, religious counselors, and coaches.
In such circumstances, where there are health impacts resulting from certain sexual activities, there is the question of whether individuals have an ethical responsibility to the public at large for their behavior.
Also in state parks it is legal to sunbathe in the nude unless a private citizen complains then you are to be removed from the premise by force if the individual does not comply.
An opposing view held by other feminists such as Wendy McElroy is that sex work is a means of empowering women, the argument here being that in sex work women are able to extract psychological and financial power over men which is a justified correction of the power unbalance inherent in a patriarchal society.
If sex work is accepted as unethical, there is then the dispute over which parties of the contract are responsible for the ethical or legal breach.
Traditionally, in many societies, the legal and ethical burden of guilt has been placed largely on the sex worker rather than consumers.
In the ancient Levant, persons who committed homosexual acts were stoned to death at the same period in history that young Alcibiades attempted to seduce Socrates to glean wisdom from him.
As presented by Plato in his Symposium, Socrates did not "dally" with young Alcibiades, and instead treated him as his father or brother would when they spent the night sharing a blanket.
In Xenophon's Symposium Socrates strongly speaks against men kissing each other, saying that doing so will make them slavish, i.e., risk something that seems akin to an addiction to homosexual acts.
However, Scanlon's system, notably, goes in a slightly different direction from this and requires that no person who meets certain criteria could rationally reject a principle that either sanctions or condemns a certain act.