As anyone who has done a retreat knows, the mind is a difficult beast to tame. During the course of a session, it is inevitable that various difficulties will arise. These can take many forms; boredom, pain, desire and restlessness are among the most familiar. If the yogin doesn't have skillful means for dealing with these states, they can lead to such discontent as to force an early end to the session. Leaving a retreat early because of such mind states is to be defeated by the defilements.
Meditation is a skill, and like any other skill part of the learning process involves mastering various techniques. Dealing with negative mind-states requires the judicious use of specific preactises, just as medical skill requires the use of specific medicines for various ailments of the body. To this end, a meditator should develop a repertoire of secondary practises to supplement the primary exercise. One special family of such meditations are called the "Four Protective Meditations."
They are given this name because they guard the mind against the arising of negativity. To continue the medical analogy, these are preventative medicine. In this regard, the recommendation is to do some of each exercise on the first day of a retreat, or before beginning a period of insight work. They plant seeds in the mind that will help later on. A brief word about each;
The sign of this meditation is an emotional state, an open-hearted acceptance and feeling of goodwill towards all sentient beings. The traditional formula is the wish that "all beings be well and happy." It can be developed in a variety of ways, but the method most suitable in the context of protective meditation is the method of general pervasion. This refers to the spreading of loving-kindness out into the universe in increasing circles, beginning with love extended towards yourself, then out towards all beings in the room, in the locality, the province, the country etc. through to all beings on the planet earth and then out into the greater universe.
The initial stage of extending loving-kindness toward yourself is absolutely crucial. Many people these days have negative self-images and find it difficult to really love themselves, so it may take work to raise the feeling. Don't be concerned that this may be "selfish." It isn't. You cannot love anyone else in depth unless you love yourself, and conversely, if you do manage to arouse genuine loving-kindness toward yourself, you will be unable to withhold it from others. It will spontaneously overflow.
Remember from the outset that the wish is "may this being (or all beings) be well and happy." It has nothing to do with approval or liking. This is important because to be effective loving-kindness must be universal. The meditator must learn to love all beings without discrimination between the near and far, the liked and disliked, the good and evil or any other pair of dualities. The liberating effect comes from the boundlessness of the meditation.
The second protective meditation is the contemplation of the Buddha. This is both a devotional and an inspirational practise. The meditator should make himself familiar with the attributes of the Buddha and contemplate them. This can be combined with a puja.
Some preliminary research to gain knowledge of the Buddha's attributes is essential. The traditional method is to work through the list given in the "Mirror of the Dhamma," that is the chant beginning itipi so... For a full description of the attributes, see my article on doing Buddhanusati But here is a bare-bones translation;
The meditator goes through the list, using creative imagination to visualize what a Buddha would be like. This should be combined with visualization of the Buddha. The idea is to imagine what it would mean for someone to be completely purified and awake. The practise is best done in front of a shrine, using a Buddha image as a point of reference.
The third contemplation is one that is not as widely practised as it ought to be. This is the meditation on the body, focussing on the "unlovely" aspect. The traditional method is to visualize the corruption of a dead body. In the East, real corpses are still occassionally used for this purpose. The monk will sit by the corpse in the open air, preferably at night. If a corpse in its natural state has been seen and contemplated, it can be stored in the mind as a memory image for later use.
Photographs can also be used, and often are. You do however, lose the effect of the smell. It is also possible to simply use one's imagination. One method is to visualize a corpse decaying through stages. The suttas list the following;
One very effective variation is to start with the image of your own body freshly dead and to go through these stages, continuing the decomposition until --poof-- nothing at all is left. This is to go from a shocking, almost violent image through increasing peacefulness to emptiness.
This is not the same as the above. This is a contemplation on impermanence. The meditator is trying to face the stark reality that she will die. One method is to think of beings known to one who have already died and to raise the thought; "just as this one died and is no more, so I too will not escape that fate." If this method is used, the yogin should be very careful not to dwell on the death of loved ones which will lead to sorrow or regret. Instead, neutral beings should be used. Think of people you once knew who are now gone and realize this is a universal fate.
The Visuddhimagga also gives a more detailed method with a list of eight separate aspects to contemplate.
These meditations protect the mind of the meditator in a very profound way. If these four contemplations, two joyful and two sobering, are taken into the depth then many painful negativities can be avoided. The meditation on loving-kindness opens the mind to a joyous acceptance and prevents the arising of the painful states based on ill-will, such as anger, self-criticism etc. The meditation on the qualities of the Buddha fills the mind with light and bliss and overcomes a host of negativities. The meditation on foulness allows a perception of the seed of corruption inherent in all flesh, and thereby helps to prevent discontent arising through sensual desire. Finally, the meditation on death should arouse a sense of urgency and prevent the arising of sloth and boredom.
These benefits, however, as important as they are, are not the whole of the story. The paragraph above deals with the protections strictly from a psychological viewpoint. There is another side to the protections. It is taught that they will establish harmonious relations with the unseen beings, protecting one from ghosts and other malevolent entities, at the same time attracting the help and protection of the devas. To this end, the first two are especially powerful and in particular the meditator should not neglect to extend loving-kindness to the devas of heaven and earth. This is the literally protective aspect of these meditations.