The Sanskrit word 'upaya' is usually translated as 'skillful means', 'expedient means', or 'skillful methods', and is a central concept in Mahayana Buddhism, which includes both Zen and Tibetan traditions. Upaya refers to practices, rituals, teachings, and even teaching methods that are considered a means to an end - a means to enlightenment - for a particular student or group of students. They are considered provisional or expedient truths rather than ultimate truth itself, on the pathway to enlightenment.
The Lotus Sutra, often considered the defining text of Mahayana Buddhism, discusses upaya in great detail, including the well-known 'white lie' story by the Buddha. In this story, the Buddha tells of a rich man with a large house and many young sons. A fire starts in the house, and the man is desperate to get all of his sons and staff out of the house as quickly as possible without causing a chaotic panic. He tells each son that their favorite toy is just outside and they need to rush to get it. All exit safely.
The Buddha's teaching in this story is that the father telling his sons there are toys outside in this case is upaya, or skillful means, and actually a form of compassion, because it saves the children from suffering and even death. So too, a teacher's methods, and the practices or rituals employed by certain traditions, even if unorthodox, may be skillful means if they are effective in leading someone from delusion towards enlightenment, and therefore rooted in compassion. The value of a teaching or practice is seen in its effectiveness, and is contextual, rather than being viewed in universal terms.
This idea of upaya is often used to explain 'crazy wisdom' stories that appear in both Tibetan and Zen traditions, in which teachers appear to engage in eccentric and contradictory behavior, but ultimately lead their students to great awakenings. The esoteric teachings of Vajrayana Buddhism are also considered skillful means - the rituals, mantras, energy practices, and other methods that are different from other branches of Buddhism are considered ways of using the aspects and energies of daily existence as skillful means to attain enlightenment.
Another understanding of upaya is rooted in the 'empty fist' metaphor - the idea that a teacher holds up an empty fist and tells each student that his or her favorite thing is in the fist, as a parent might do when trying to entice a child. The idea is that although we each may think we want enlightenment - freedom from suffering - the nature of existence and our ego keeps us bound to old patterns of attachment. In order to overcome these, we first need to engage them through our desire for happiness, power, love, respect - whatever motivates us personally. Then over time, we will come to a deeper understanding, and move beyond such motivations.
Skillful means in terms of teaching means knowing which practices and teachings are appropriate for which student. Skillful means for an individual practitioner means knowing which practices, of the ones we have been taught, apply to which of our life situations. In both cases, upaya implies that the pathway to enlightenment is highly individual and contextual, and that Buddhism is a very fluid tradition. We each can and should process different teachings and practices at different times. Upaya also takes the wind out of cross-sect or cross-faith debate about which practices or teachings are valid and which are not, because a practice's validity is based on its effectiveness for even one individual, not on a claim of universal truth.
Applying upaya in our daily lives requires a great deal of self-honesty. If we encounter a situation in which we become angry, for example, we need to apply skillful means to ourselves to handle the situation wisely and productively. If we are in a situation where we need to convey something to someone that may be painful for them to hear, we apply skillful means to our method and way of speaking with them. In either case, we have to be able to put aside our desire to just act impulsively - we must apply some self-awareness to our process.
Obviously, the idea of upaya can be abused, by either a teacher or our own ego. An unethical teacher could use the idea of upaya to insist controversial practices or teachings are appropriate when they are actually a means of control or abuse. On the individual level, we might convince ourselves that we don't need a certain practice or teaching, or that another one that we find more pleasurable is appropriate, when in fact we are just being indulgent or avoiding facing a difficult aspect about ourselves. For this reason, in many Mahayana Buddhist teachings, upaya is often paired with 'prajna', meaning wisdom, and 'karuna', meaning compassion (in Pure Land Buddhism, upaya, prajna and karuna are called the Three Gates to Liberation.) Upaya rooted in wisdom and compassion guides us to enlightenment.
To learn more about the Lotus Sutra, including an entire chapter on skillful means, try Zen monk and teacher Thich Nhat Hanh's Peaceful Action, Open Heart:
Or, for some examples of Tibetan 'crazy wisdom' stories, along with beautiful contemporary thangka artwork, try: