Official Scientology views on sex are based on the written works of Church of Scientology founder L. Ron Hubbard. These make up the Standard Tech, or core doctrine, of the Church.

In 1982 Hubbard authored Pain and Sex, in which he is critical of psychiatrists (referred to as "psychs"), and ascribes the woes of society to "the psychs".^[1] According to Hubbard, under the "false data of the psychs ... both pain and sex are gaining ground in this society and, coupled with robbery (which is a hooded companion of both), may very well soon make the land a true jungle of crime".^[1]

In Hubbard's original Dynamics, "Sex" was the Second Dynamic, representing both the sexual act and the family unit.^[2][3] According to Reuters: "The second dynamic includes all creative activity, including sex, procreating and the raising of children."^[2]

In the Life Orientation Course (written in 1979 before Hubbard's death but published after in 1990), the definition replaced "Sex" with "Creativity". This new definition was later used in compiled materials such as the 1998 Introduction to Scientology Ethics. However, some Scientologists claimed the Church had altered the Dynamics, minimizing the importance of sex: "It also incidentally includes sex as a mechanism to compel future survival".^[4] According to a statement made by the Church of Scientology to MSNBC, pre-marital sex is prohibited for Scientologists who are members of the organization's elite order, the Sea Org.^[5]

The tone scale is a gradient chart that describes rational or pro-survival behavior on an individual. The higher a person is in tone scale the higher is his ability to survive. The tone scale is described in detail in the book “The Science of Survival”. Chapter 18 of this book describes the tone scale as it applies to second dynamic: “At the highest MEST point of the Tone Scale, 4.0, one finds monogamy, constancy, a high enjoyment level and very moral reaction towards sex.”^[6]

Selected citations from the Chart of Human Evaluation:^[6]

In The Creation of Human Ability, Hubbard hailed "compelled admiration" as an important step of progress in "Knowingness", as measured on his "Know to Sex" scale. Hubbard stated:

It can be observed that the eating of living flesh or live cells delivers a kind of admiration to the taste, and it can be observed that under torture, duress of all kinds, the tortured one will suddenly, if degradedly, admire his torturer.

Hubbard then went on to say that sex was an even better "communication system" for the same purposes of forced "admiration", and defined the sex act, consensual or otherwise, as "an interchange of condensed admiration particles".^[7][8]

In 1950 Hubbard published Dianetics: The Modern Science of Mental Health, introducing his "science of the mind," Dianetics. He classified homosexuality as an illness or sexual perversion, taking a view that was somewhat more extreme than most, but according to Jeffrey S. Siker in Homosexuality and Religion still within the mainstream of opinion at the time.^[9]

Hubbard's "tone scale", a means of classifying individuals and human behaviour on a chart running from +40 (the most beneficial) to -40 (the least beneficial). Sexual perversion, a category in which he included homosexuality, was termed "covert hostility" and given a score of 1.1, "the level of the pervert, the hypocrite, the turncoat, ... the subversive." Such people were "skulking coward[s] who yet contain[] enough perfidious energy to strike back, but not enough courage ever to give warning."^[10][11][9]

Hubbard warned against sexual activity (including masturbation) during pregnancy. Hubbard wrote that engaging in sexual activity during pregnancy could negatively impact the baby's development.^[12] He believed sexual activity had an adverse and dangerous effect on the unborn child because it can hear, understand and experience everything going on, as well as recording it all as engrams which can haunt the person for the rest of their life. This view is at odds with mainstream science, as Paulette Cooper commented in her book The Scandal of Scientology:

Hubbard's theory never makes it really clear, at least in a manner that would be accepted by most medical doctors, exactly how engrams can be planted before a foetus had developed a nervous system or the sense organs with which to register an impression, or even how a person could retain or 'remember' verbal statements before he had command of a language."^[13]

These same beliefs form the basis for Hubbard's "Silent birth" doctrine, which dictates that no words are spoken during the childbirth process in order to avoid the baby hearing negativity and receiving "psychic scars".^[14] According to a Scientology manual on raising children, in order to avoid damaging the "prenatal" memory, a couple should be silent before and after the sexual act.^[15]

In the 1967 book The Dynamics of Life (originally written circa 1948), Hubbard states that "promiscuity inevitably and invariably indicates a sexual engram of great magnitude. Once that engram is removed, promiscuity can be expected to cease". A footnote then defines promiscuity as "having sexual relations with many people".^[16] Hubbard writes in his book The Way to Happiness that if sex is "misused or abused, carries with it heavy penalties and punishments: nature seems to have intended it that way also".^[17]

In later years, Hubbard sought to distance himself from efforts to regulate the sexual affairs of Scientologists. In a 1967 policy letter, he declared: "It has never been any part of my plans to regulate or to attempt to regulate the private lives of individuals. Whenever this has occurred, it has not resulted in any improved condition ... Therefore all former rules, regulations and polices relating to the sexual activities of Scientologists are cancelled."^[9][18]

In his 2008 book Tom Cruise: An Unauthorized Biography , Andrew Morton writes that Nicole Kidman discussed her sex life with Tom Cruise in Scientology "Auditing" sessions.^[19] Morton writes that details of Kidman's sex life with Cruise was to be leaked by the Church of Scientology if she spoke out critically against the organization after their 10-year relationship that had broke off in 2001.^[19] According to the book Kidman had fears she would be blackmailed.^[20][21] This was denied by the Scientology head in Australia, Vicki Dunstan.^[19]

According to a reporter who went undercover to investigate Scientology in London in 2007, the reporter witnessed "a number of highly unorthodox tactics and practices", including: "Pressuring new members of staff to divulge and document the minutiae of their sex lives, including the names of all those they had slept with."^[22] Luc Willems, an attorney who conducted investigations into Scientology while also a member of the Belgian Parliament, asserted that questions about sex during the Auditing process are later potentially used against these individuals: "They ask if you have sex with animals, if you're homosexual, so they make a dossier. They blackmail people. To get out of Scientology is very difficult."^[23] During Scientology "Security Checks", an "Ethics Officer" performs the Auditing process, and many of the possible questions asked during this session involve the subject's sex life, including: "Have you ever had sex with any other student or staff member?", "Have you ever used Dianetics or Scientology to force sex on someone?", "Have you ever raped anyone?", "Have you ever been raped?", "Have you ever been involved in an abortion?", "Do you have any bastards?", "Have you ever been sexually unfaithful?", "Have you ever practiced homosexuality?", "Have you ever practiced sodomy?", "Have you ever had intercourse with a member of your family?", "Have you practiced sex with children?", "Have you ever used hypnotism to practice sex with children?", "Have you ever slept with a member of a race of another color?", "Have you ever practiced sex with animals?", "Have you ever had anything to do with pornography?", and "Have you ever masturbated?".^[24][25]

L. Ron Hubbard wrote that "sex crime" on an individual investigating Scientology should be reported to the press, in order to "Make it rough, rough on attackers all the way."^[26] In an interview with Playboy magazine, Hubbard's estranged son Ron DeWolfe asserted that Auditing focused on sex and the individual's sex life, and could later be used as a form of control: "Auditing would address a guy's entire sex life. It was an incredible preoccupation. ... You have complete control over someone if you have every detail of his sex life and fantasy life on record. In Scientology the focus is on sex. Sex, sex, sex. The first thing we wanted to know about someone we were auditing was his sexual deviations. All you've got to do is find a person's kinks, whatever they might be. Their dreams and fantasies. Then you can fit a ring through their noses and take them anywhere. You promise to fulfill their fantasies or you threaten to expose them ... very simple.^[27]

Hubbard called the physical world MEST, which is something extraterrestrial Thetans temporarily operating "meat bodies", are meant to transcend and conquer.^[28][29] Scientologists often refer to their bodies as "this piece of meat," or "this meat of ours",^[30] and new recruits to the church are classified as "raw meat".^[31] Scientology is geared towards attaining "cause over MEST", attaining awareness that our bodies are undesirable physical objects that are only holding us back, and attaining the ability to abandon one's body via "exteriorization" and ultimately by becoming an Operating Thetan Clear and a Cleared Theta Clear.^[32]

• Homosexuality and Scientology
• Religion and sexuality

Note: HCOB refers to "Hubbard Communications Office Bulletins", HCOPL refers to "Hubbard Communications Office Policy Letters", and SHSBC refers to "Saint Hill Special Briefing Courses". All have been made publicly available by the Church of Scientology in the past, both as individual documents and in bound volumes.