The Third Lay Buddhist Training Precept states “I undertake the training rule to abstain from sexual misconduct.” (Kāmesumicchācāra veramanī sikkhāpadam samādiyāmi). The precept emphasizes the prevention of harm to sexual partners and concerned third parties. The precept is vague, however, about what constitutes sexual misconduct. The precept is usually interpreted in the light of the prevailing customs and mores within each distinct Buddhist community. Peter Harvey  has done an excellent job of surveying the ways the precept has been interpreted across societies and over time. My review of these interpretations below is abstracted from his survey (but any errors in it are completely my own).
Sexual misconduct traditionally includes adultery and consorting with prostitutes (c.f. Sutta-nipāta and Nāgārjuna) as well as rape and incest. Having sex with anyone who is already in a committed relationship with another is also usually considered a violation of the precept. In Thailand flirting with a married woman is seen as a violation, whereas in Sri Lanka premarital sex is proscribed. The fourth-century Abhidharma-kośa-bhāsya included the use of “unsuitable” orifices, places, or times. The Upāsaka-śīla-sūtra included frequenting brothels and the use of “instruments.” Gampopa’s (1079-1153) Jewel Ornament of Liberation included overly frequent sex (more than five successive times!) and homosexuality, whereas Patrul Rinpoche (1808-1887) proscribed masturbation in his Kuzang Lama’i Shelung. Buddhaghosa and Śāntideva both considered homosexual behavior to be a violation of the third precept, but homosexuality was tolerated and accepted in Japan, even as part of monastic life.
Where does this leave the issue of teacher-student sex? In the contemporary West, the ethics concerning teacher-student sex are still evolving. In elementary, middle, and high schools teacher-student sexual contact is not permitted as students are still (for the most part) minors who cannot give consent, and because it would constitute a serious violation of a relationship of authority and trust. Ethical rules concerning college faculty-student sex are less clearly delineated since many students are no longer minors. Some colleges forbid it, others merely discourage it. Ethical guidelines recognize an inherent conflict between grading and writing letters of recommendation for students and being in a sexual relationship with them. While faculty-student relationships occur with considerable frequency, there’s also a considerable degree of queasiness about the potential for abuse of power within these relationships. In counseling and clinical psychology, therapist-client sexual encounters are considered ethical violations. Psychology’s ethical standards recognize the danger of abuses of power, the need for therapist objectivity, and the irrational idealizations that clients may project onto therapists. Lastly, we might mention that sex abuse scandals within the Roman Catholic Church have increased public awareness of the real and enduring psychological and spiritual harm caused by violations of clerical authority and trust.
These issues of trust, authority, abuse of power, idealizations and projections, and the need for teachers to retain impartiality and objectivity are all relevant to the question of relationships between Buddhist teachers and their students, and there have been attempts to develop codes of ethics for Buddhist teachers. For example, Spirit Rock has developed a code of ethics for teachers in the Insight Meditation tradition that includes the following paragraphs:
“We agree to avoid creating harm through sexuality and to avoid sexual exploitation or relationships of a sexual manner that are outside of the bounds of the relationship commitments we have made to another or that involve another who has made vows to another. Teachers with vows of celibacy will live according to their vows. Teachers in committed relationships will honor their vows and refrain from adultery. All teachers agree not to use their teaching role to exploit their authority and position in order to assume a sexual relationship with a student.
Because several single teachers in our community have developed partnerships and marriages with former students, we acknowledge that such a healthy relationship can be possible, but that great care and sensitivity are needed. We agree that in this case the following guidelines are crucial:
A) A sexual relationship is never appropriate between teachers and students.
B) During retreats or formal teaching, any intimation of future student-teacher romantic or sexual relationship is inappropriate.
C) If interest in a genuine and committed relationship develops over time between a single teacher and a student, the student-teacher relationship must clearly and consciously have ended before any further development toward a romantic relationship. Such a relationship must be approached with restraint and sensitivity – in no case should it occur immediately after retreat. A minimum time period of three months or longer from the last formal teaching between them, and a clear understanding from both parties that the student-teacher relationship has ended must be coupled with a conscious commitment to enter into a relationship that brings no harm to either party.”
Similar codes of ethics have been developed by a number of Zen communities, including ones where teacher misconduct has occurred in the past (e.g., San Francisco Zen Center, Kwan Um School of Zen).
Given the evolving consensus about teacher-student relationships, why does misconduct continue to occur? The answer is simple: because all human beings are imperfect, and because any position of power invites both temptations and opportunities for abuse. The Buddhist community, however, may have several unique factors that complicate addressing this issue.
Certain tantric practices (e.g., the use of mudras or “seals”) may open the door for potential abuse unless there is a widely understood consensus on ethical guidelines regarding their use. Similarly, the idealization of “crazy wisdom” within tantric traditions may lead students to rationalize teachers’s unacceptable behaviors, and teachers to rationalize being out-of-control.
The biggest obstacle within Buddhism, however, may be the idea of “Enlightenment” itself. Enlightenment is traditionally described as something that puts a permanent end to unwholesome desiring. Once one has achieved Enlightenment, there’s no backsliding. Enlightened Beings are, by definition, incapable of sexual misconduct. Any teacher who believes this is at risk for becoming an abuser. Any student who believes this is at risk for rationalizing and accepting abuse.
The idea that one can have a magical experience that makes one perfect and makes one invulnerable to harmful temptations is a fairy tale. Everyone’s brain contains a hypothalamus, and no amount of meditation or insight can surgically remove it. The hypothalamus is the seat of desire in the human nervous system, including sexual desire. We have a wonderful cerebral cortex which can dampen, override, and modify hypothalamic output, but not eliminate it. As Freud might say, we all have an “id,” a dynamic, insatiable source of passion and desire, that is a permanent part of our psychological constitution. Buddhism teaches us to be heedful and mindful of desire and deal with it intelligently in order to be fully and completely human. It shouldn’t teach that there’s a stage when we no longer need to exert due care.
Buddhist practitioners often experience powerful meditative experiences that have real transformative power. These realizations, however, do not completely obliterate temptation or the repetition and acting-out of deeply ingrained behavioral patterns. Meditative realizations need to be gradually actualized and reinforced. Psychotherapists know that a genuine insight in one situation does not automatically generalize and transfer to other situations. There’s a process called “working through” that needs to occur before one can actualize insight across circumstances. Similarly, Korean Zen Master Bojo Jinul (1158-1210) taught that the Buddhist path is one of “sudden enlightenment” followed by “gradual cultivation.” We never finish our development. Enlightenment is a horizon we aim at, not something we achieve.
That’s why codes of ethics will always be necessary. That’s why there will always be Buddhist teachers who will fall short of embodying them. That’s why our life needs to be one of continual practice.
-  Harvey, P. (2000). An Introduction to Buddhist Ethics. Cambridge, UK: Cambridge University Press ↩