The third precept reads: Kamesu micchacara veramani sikkhapadam samadiyami, “I undertake the training rule to abstain from misconduct in regard to sense pleasures.” The word kama has the general meaning of sense pleasure or sensual desire, but the commentaries explain it as sexual relations (methunasamacara), an interpretation supported by the suttas. Micchacara means wrong modes of conduct. Thus the precept enjoins abstinence from improper or illicit sexual relations.
Misconduct is regard to sense pleasures is formally defined as “the volition with sexual intent occurring through the bodily door, causing transgression with an illicit partner”.8 The primary question this definition elicits is: who is to qualify as an illicit partner? For men, the text lists twenty types of women who are illicit partners. These can be grouped into three categories: (1) a woman who is under the protection of elders or other authorities charged with her care, e.g., a girl being cared for by parents, by an older brother or sister, by other relatives, or by the family as a whole; (2) a woman who is prohibited by convention, that is, close relatives forbidden under family tradition, nuns and other women vowed to observe celibacy as a spiritual discipline, and those forbidden as partners under the law of the land; and (3) a woman who is married or engaged to another man, even one bound to another man only by a temporary agreement. In the case of women, for those who are married any man other than a husband is an illicit partner. For all women a man forbidden by tradition or under religious rules is prohibited as a partner. For both men and women any violent, forced, or coercive union, whether by physical compulsion or psychological pressure, can be regarded as a transgression of the precept even when the partner is not otherwise illicit. But a man or woman who is widowed or divorced can freely remarry according to choice.
The texts mention four factors which must be present for a breach of the precept to be incurred: (1) an illicit partner, as defined above; (2) the thought or volition of engaging in sexual union with that person; (3) the act of engaging in union; and (4) the acceptance of the union. This last factor is added for the purpose of excluding from violation those who are unwillingly forced into improper sexual relations.
The degree of moral gravity involved in the offense is determined by the force of the lust motivating the action and the qualities of the person against whom the transgression is committed. If the transgression involves someone of high spiritual qualities, the lust is strong, and force is used, the blame is heavier than when the partner has less developed qualities, the lust is weak, and no force is used. The most serious violations are incest and the rape of an arahant (or arahatess). The underlying root is always greed accompanied by delusion.