There are 21 classic semdzins in the upadesha/menngagde Dzogchen tradition. They are practices (as well as rushens) that gives you a clear experience of Nirvana as opposed to Samsara. They are used to help people who have received Direct Introduction to the Primordial Stare (rigpa) to revisit the state and not keep doubting what the state is. It is a series of practices that helps to grasp the second statement of the final will of Garab Dorje.
Sem-dzin means to 'hold the mind' or to focus.
Nonmeditation is the essential unique Dzogchen meditation. For nonmeditation to kick in, the natural flow of consciousness can be dammed by what we call 'semdzins'. Semdzins "hold" the mind momentarily, during which time the window to the nature of mind is thrown open or enlarged and nonmeditation proceeds. The most efficient function of the semdzin may lie in the discharge of a misguided effort to inhibit the natural flow of nonmeditation.
Longchempa collected together the twenty-one semdzins in the 14th century and wrote the short descriptions of them in his Dzo Dun. In that all-inclusive tome, the twenty-one were presented as separate but commensurate, categorized, as they are here, under three headings according to three specific and graduated functions. Those three purposes are pacifying the mind, releasing attachment and revealing the nature of mind. This categorization, appearing somewhat intellectually partial and arbitrary, need not be accepted uncritically dogmatically and practised accordingly. Indeed, once the twenty-one semdzins have become familiar according to Longchempa's rubric they can be utilized at will, all equal as gateways into the nature of mind and the basis of experimental mediation.
Nonmeditation is the sole crucial method of Dzogchen meditation, yet nonmeditation cannot be programmed or devised. These twenty-one semdzins are all the same or similar open-sesame keys to that nonmeditation, meditation that allow or enable nonmeditatiom, to 'make' space for 'nonmeditation.' The natural flow of consciousness is dammed by the semdzin and mind is 'held' momentarily, during which time the window to the nature of mind is thrown open, or enlarged, and nonmeditation proceeds with clarity. A powerful head of energy may be built up behind the dam of discipline, and particular mindforms may be engendered, such as high awareness with varying degrees of bliss, radiance, throughtlessness and/or emptiness. But these experiences are secondary and irrelevant to the central concern, which is nonmeditation. In this way the semdzins remove obstacles to to naturally-arising nonmeditation rather than create the conditions for it.
Many of the exercises herein may be found on mahayana and some even on hinayana paths, but in these lesser, causal, vehicles, a relative, temporal, goal is anticipated and when the anticipated end is achieved it is greeted with a sense of success and attainment - another, higher, rung on the ladder has been reached. On the contrary, in Dzogchen, in the case of every semdzin, the already extant, undeniable, nondual refuge is the outcome.
It is vital that these semdzins are not conceived as 'method'. Indeed, the possibility of any Dzogchen realization - nonmeditation - is thwarted by any apperceptive idea of attainment. Likewise, the idea that nonattainment is the "method" of attainment of realization can trip us up. It must not be given any positivistic status that can turn it into an objective aim. Neither nonmeditation nor nonattainment can be objectified by "the knower", or the intellect, without undermining its actuality - its authenticity. That is the nature of the nondual. If the semdzin take us to a place where we no longer hanker after attainment or nonattainment and thus allow Dzogchen to seep into our no-loinger-desirous intellects then their function is realized. So, put aside the idea that these exercises provide a ladder to Dzogchen attainment. If they alleviate the pressures of samsara to the extent that we give up all thought of spiritual accomplishment, then they have been particularly useful. If they provide a non-temporal gap through which the natural light of the mind may shine, they will have proved their worth.
If the dangerous elevation of the positivistic effects of the semdzins to concepts of "meditation" and "practice" - always imminent - become acute, then it is probably best to ignore their practice and move on immediately to Dzogchen non meditation or the Dzogchen preliminaries. The dangers inherent in making practice of the semdzins a habit may well provide the reason why Longchenba spent so little time in their exegesis. If this warning is taken to heart and the semdzins are rejected as “method”, if they are spurned as steps up to a diving board, as it were, from where we can launch ourselves into the nature of mind, take also the warning that it is equally dangerous to use them as support along the way when we find ourselves in an apparently inescapable dualistic dug-out. The answer to both situations is the complete relaxation that is nonfiction, “or doing nothing”, rather than a return to the already rejected positivistic methodology of vajrayana.
So although these semdzin are not to be practiced as part of a fixed regular sadhana, it may be advisable to undertake a short retreat or a period of intense engagement with each of them, several of them, or one of them, to gain lucidity and familiarity. Dedicated practice will provide the familiarization needed to enter into any of them effortlessly when required and the ability to let go of them immediately - or at least at the end of the period of practice. Their perfect utility is accomplished when one or another of the twenty-one comes into mind spontaneously during nonmeditation and is immediately and effectively activated. Then they may be included in regular sitting sessions.
In the initial period of assimilation, practice whatever of the twenty-one semdzins is intuited as part of the flow, one alone, or two or more in succession, in any order, or the whole twenty-one from beginning to end. Giving more or less time, an hour or a week or a month to each, one after the other, until they arise fluently whenever they are required.
When the semdzins have been assimilated, each yogin / yogini will have his or her own personal preferences amongst them, more experience having been gained with some than with others, some always seemingly applicable and making perfect sense, arising spontaneously and clearly and usefully. Others will arise only occasionally or not at all. Sometimes, in a kind of lacuna, these semdzins are like water off a duck’s back - we just do not get it. So be sure that nonmeditation - simply sitting - is the main point and the semdzins only functioning as a back-up.
Perhaps the intervention of a lama prescribing what is most relevant for one's own mind is a more economical and expedient manner of proceeding, and such a lama may be able to provide personalized instructions. If a lama who knows you well is not available, then take Longchenpa's instruction to heart and fill it out with Chogyal Namkhai Norbu's comments. The Commentary consists both of definitive and provisional instructions, "definitive" insofar as it elaborates the sometimes scant Tibetan rubric, and "provisional" in that it posits varied approaches - different strokes for different folks - to the same end.
Again, finally, it is imperative that the semdzins are not perceived as a means to a temporal end. In such a case they are reduced to rungs on an endless ladder stretching up to heaven, and Dzogchen becomes merely a name for another school of Mahayana Buddhism. Insofar as we perceive Dzogchen as a means to an end rather than the end itself, and insofar as we see that end as separate from the nature of our actual state of mind in the here and now, we demean it, reducing it to another religious enterprise. Dzogchen is not an escape from the maelstrom of everyday life; it is the total acceptance of whatever comes down, whatever it may be, so that total unitary identity is assured - no particle remaining separate and unassimilated - and simultaneously at one with the nature of that experience, which is the nature of mind.
Visual a white, luminous, "A" on the tip of the nose. On the outbreath the "A" moves away; on the inbreath the "A" returns mixed with the breath. Training day and night in this manner the extraordinary experience of freedom from mental quiescence and activity (mental emanation and absorption) arises.
If you get tired exclaim the syllable PHAT: sometimes let consciousness run free and then forcefully enunciate that syllable. A state of consciousness of thoughtless amazement will arise and the mind is held as pure presence until another thought arises at which time again enunciate the syllable PHAT. Practicing this through night and day the meditation of empty luminous mind in its natural condition arises.
Joyfully laugh the exclamation HA, short and forcefully (start with one and increase to five), and as with the exclamation PHAT the mind is secured and the experience of thought free clarity arises.
Sit in an exposed place and in seclusion, and holding your knees to the chest first turn your head one way and then the other, and then turn your shoulders and shoulders and torso together. Keep your knees to your chest as tightly as possible and turn strenuously, forcefully. Outer appearances will be shot through with successive colors until appearances cease by themselves and whatever arises - which is to say your vision - will be indefinable, and the experience of self-liberating appearances arises.
Identify long resonant vocalized HUNGs with the breath and when intractable thoughts or thought-trains arise use the short exclamation HUNG to disperse them. Unmoving from our original condition experience of clarity of the nature of thought arises.
Visualize the syllable RAM in the navel centre, bright, radiant, translucent, red in color, glowing and then burning. Fixate on the syllable. Sound the syllable softly as you visualize it. Heat arises.
Visualize oneself as Vajrasattva; visualize Vajrasattva on the tip of the nose, mix that visualization with the outbreath and inbreath; visualize an infinite number of Vajrasattvas emanating from the pores of the skin and the nine bodily orifices on the inbreath and returning on the outbreath. With an attentive mind the experience of consciousness as magnificent pure luminosity arises.
Focus the mind on a white/red sphere the size of a pea between the eye brows. Experiences of energy will arise thereby.
The central channel, and the roma (left) and kyangma?? (right) are like straight staffs down the center of the body, the right and left channels exiting at the nostrils: exhale forcefully like shooting an arrow, expelling all disease, faults and errors with it, and then inhaling catch the prana as with a lasso and insert it into the central channel at the junction four fingers below the navel. Rising up the central channel through the four chakras, the prana suffuses the body with awareness. Experiences of the empty clarity of pure presence (rikpa) arise.
On the tip of the nose is a prana sphere that is carried away for a meter to a kilometer by the exhalation and brought back by the inhalation. Focus on this and you will experience thoughtless clarity.
Visualize a small white "A" in the heart center and focus unwaveringly on a net of five-color rainbow light - translucent, clear, insubstantial emanating from it in all directions bounded by the sphere in which you sit. You experience the pure clear light.
Visualize a ball of light on the fontanelle filled up with all mind and energy that with the sound of the syllable HUNG rises into space moving higher and higher in the sky until it vanishes altogether. In this way you experience emptiness beyond thought.
Focus attention in the ear and relax. Thereby you will experience the samadhi of sound.
Focus upon the tiny form of Kuntuzangpo (Samantabhadra) in a globe of blue light in the heart center. Thereby you will experience pure clear light, and you will cultivate the clear light of the bardo, and at death there will be buddha deity, relics (ringsel) and rainbow light.
Through discursive and experiential analysis of appearances and ego, arrive at the emptiness of both objective and subjective aspects of experience. Finally, without any mentation, the experience of nondual emptiness arises.
Gaze intently at whatever appears and regard it as utterly pure and empty. Applying this to all forms and all sounds, etc, all appearances are experienced like condensation on a mirror.
Regard appearances without any centrality of focus, without solid ground, without any invariable point of reference, uncertain, undependable, always variable. Whatever arises, appearing in a variable and non-veridical variety, is thus seen as delusion (a lie) and utterly indeterminate. Training in impermanence brings experience of freedom from grasping.
Focus consciousness unwaveringly without any distraction upon whatever of the five elements appears as earth and rock, ice, water or steam, fire, air or wind, or space. You experience self-liberation in the that place of focus like dream experience.
Whatever appearance arises in consciousness, whatever moves in the necklace-sequence of instants, intuitively apprehend the indivisible, thoughtfree ultimate place. Holding the mind in this way the samadhi of intrinsic non-thought arises.
At the arising of dualistic appearances (subject/object, inside/outside) gaze intently at the crux (totality) of that polarity and the experience of the serene intrinsic purity of nonduality will arise. Also, by taking the bliss of male and female buddha-union as the path the experience of nondual bliss and emptiness arise.
Visualize pure presence (rikpa) as vanished into space, and visualize all appearances and mind as floating in the space unsupported, and visualize the space as all things. Experience of great boundless emptiness arises.