Three Kinds of Grace
The Tantras distinguish three kinds of grace: intense, average and weak, each of which is in turn divided, according to its intensity, into three more types (Ch. XIII).
Upon grace depends desire: the aspiration of one's entire being to destroy one's bonds or finally, the desire to liberate oneself while continuing to enjoy until death the pleasures of this world. According to the intensity of this desire, the adept will encounter a very potent guru or a simple yogin. Absorbing himself in his teacher, he arrives at a spiritual level corresponding to his consummate inclination.
The immersion of the disciple's consciousness into the teachers's vaster consciousness is precisely that which enables the initiate to break through his own limitations. We will thus study the various ways in which transmission from guru to sisya occurs, according to the co-penetration of divine grace in master and disciple upon which this transmission depends.
The ultimate Consciousness, which had been obscured, can illuminate itself anew with or without an intermediary: the highest degree of communion  between master and disciple is present from the start, translating itself into pure beatitude.
All endnotes appear in a separate page: endnotes.htm Brief endnotes are reproduced in the text as footnotes. Where suggested, click on the blue link to see the full endnote on the Endnotes page.
Three other kinds of communion utilize various intermediaries, ranging from a simple effort of the will to strenuous practice. The efforts of guru and sisya increase proportionally as grace lessens and their communion becomes less perfect.
The first of these is peculiar to Siva, and has as its sole support the will. The second, dependent on the divine energy, has recourse to intuitive knowledge; and the third involves the sense organs, the entire body, the breath, and the mind.
In truth, Siva transcends the initiator, the initiated and even initiation itself. How then to speak of the co-penetration of teacher and student? Who other than himself could penetrate into Siva, the single Reality? We must with Abhinavagupta envision this question from a relative point of view, so that obstacles disappear spontaneously according to the intensity of the grace received:
1. Crushed by the most powerful force of divine energy, the chosen being attains identity with Siva-Bhairava, [a] but forthwith dies or, if he survives a while longer, he, struck by inertia, cannot serve as a guide.
[a. Manifestation of Shiva associated with annihilation. en.wikipedia.org/wiki/Bhairava ]
2. When grace, still intense, although to a lesser degree clearly establishes itself at the onset and is assimilated by the body, the ardent devotee of Siva accedes to the state of genius master  of which we have already spoken. He instantly discerns the resplendent Reality overflowing with joy, that is to say, the I in which all is reflected.
This grace can also be transmitted by a master who, unmoving at the center of the energy, works by simple spiritual radiation. One who benefits from such grace must be animated by great fervor, unattached to all but the essential, Siva.
Two conditions must be met: he must first possess a Self that is very pure, which understands instinctually that to know Consciousness in all its fullness, nothing is required – neither yoga nor concentration nor any particular activity. In effect, since Consciousness shines spontaneously, the only means by which it can be known is simply by its own brilliance.
Beyond this certainty that Consciousness is self-luminous, the student must also be convinced that his guru bathes in this ineffable Reality and can confer grace heart to heart without intermediary (anupaya) "as we light a lamp with another lamp." This conviction or intuitive vision (darsana) is essential, for it is by this and this alone that the disciple can accede to the state of his teacher.
These conditions met, the sisya must now hear the words of his teacher (perhaps a simple allusion to Siva or of his own identity with the Self) for this knowledge to be reflected in him as in a mirror; but he must be intensely conscious of his identity with Siva. In this way, after achieving complete identification with his guru, he is absorbed in undifferentiated Consciousness. He rests in the beatitude whose taste remains the same throughout. Such is the best of disciples who, according to Abhinavagupta, "tastes continually complete happiness."
Here the teacher wastes neither advice nor instruction, for a disciple deserving of this ineffable transmission needs no explanation. If he is an inferior disciple, ignorant of the subtleties of mystical life, the guru's function is to silence his "lies," all speech being lies in comparison to the Real.
Grace, still intense even if diminished, proceeds from divine will; it arouses in him who receives it such a desire for liberation that this desire soon leads Him to the perfect teacher (sadguru). And this meeting occurs naturally, whether he discovers him on his own or through friends. It is also this grace which incites him to leave an incapable guru for the rewards of a true guru equal to Siva.
Having recognized the Self, the mystic liberates himself (immediately or gradually) and becomes free while alive; he will not be reborn. Since in this case liberation depends upon perfect knowledge, the guru must be a gnostic who possesses complete mastery of the literature and of the categories of reality; a simple yogin would be of no help here. This jnanin may be an illuminated teacher or an initiated teacher. Like the master of the preceding initiation, he transmits divine favor in an ineffable manner.
Let us, however, note a difference between the teacher's attitude and that of the disciple. The guru is no longer entirely inactive; he examines the disciple attentively in order to judge whether he, purified by grace, is deserving of immediate communion. For his part, the disciple is unaware that the master is at the center of Reality, free of ways and means, his personal conviction thus no longer playing a preponderant role. Moreover, the transmission itself presents slight differences: according to one Tantra, the master acts on the disciple like a serpent which by its look alone ejects its venom into the distance.
During this second kind of darsan, the disciple is seated face-to-face with the guru, upon whom he is contemplating, and establishes himself easily in the supreme Reality. The illuminated consciousness of the master passes into that of the sisya by the intermediary of speech, during the explanation of a scripture, or by means of a mystical formula (mantra) which is the intuitive understanding of "I", the greatest formula. The guru may still enter his disciple's breath, as we will later explain. Finally, he confers upon the student a liberating initiator which at the moment of death separates him from his vital breaths; his slightest attitudes and words are charged with spiritual force. By one or more of these initiations, he manifests the potency of I to the disciple whose devotion and faith have given total satisfaction; for what is essential is the constant love which joins guru and sisya.
Let us note still a third form of darsana without intermediary, this one also due to intense grace. Certain privileged beings perceive in dreaming or during samadhi accomplished men and women called siddhas and yoginis. Having received from them dicta to execute remarkable acts requiring great courage, they absorb themselves into the inexpressible Reality as soon as they have obeyed.
Comunion with Siva
If the disciple cannot penetrate immediately into the luminous Essence merely by the presence of a great master, he must, to soar towards the Absolute, serve as the springboard to his free energy. Rejecting then all that is not Siva, he loses himself in Him. This "via remotionis" [to arrive at God by negation or removal] gives him access to the cosmic plane wherein the Self, resplendent in its original majesty, is identical with Siva, the source of all energies.
So perfect a communion of Siva, master, and disciple cannot occur except in a sisya who is vigilant, without desire, purified of dualistic thought (nirvikalpa), having a guru who is gifted with illumination. The guru indicates to the disciple that the universe, as divine energy, reflects itself in Siva, universal consciousness, and has no reality but in Him. Thus perceiving the world as a reflection of his own consciousness, the disciple is no longer its slave but its support. The master uncovers other connections between the I and the Universe, whether the I emanates it by means of phonemes [sounds in speech] or whether it reabsorbs it at the moment when all mantras contract into a single one, aham, the absolute I, identical to universal and quiescient Bhairava.
Communion of Energy
Immediate or divine communion is rare. In general, even with the great mystics whose number, according to Abhinavagupta, is extremely small, grace, still strong, is firmly established,  but reveals its power gradually over the course of his life.
[Endnotes 6 and 7 are out of order in the original.]
The merging of divine Energy, master, and disciple must necessarily continue to deepen, and consciousness must be continually experienced. It is thus with the aid of all the energies carried to their maximum that the initiate will liberate himself from his bonds, attaining first illumination and, later, identification with Siva.
On the path of the energy where knowledge plays an essential role, the guru is irreplaceable. For the guru dissolves the obstacles between disciple and Reality: imagination, doubts, lack of confidence. In addition, he reinforces his faith and his conviction. Subtly, he acts upon the disciple's thoughts and unconsciousness, purifying them of their tendencies towards duality. He transforms misconceptions – ideas of enslavement – into their opposite: e.g., certainty of the identity of the Lord (whose body is the Universe) and the Self (its consciousness). Shorn up by the constant practice of contemplation (bhavana), such a conviction eliminates the doubts and the fluctuations which impede adherence to Reality.
The guru encourages in the sisya proper discrimination (sattarka), the power to discern between the essential and the superfluous. Thus, the initiate learns to recognize the characteristics of sound teachings, those of a true master gifted with intuitive knowledge (pratibha). Similarly, the guru teaches the uselessness of indirect means taken from yoga (control of breath, postures and other techniques) given that on this path all that is necessary is the luminous understanding which issues from penetrating discrimination.
In order to exorcize the phantoms of pure and impure,  as well as the moral, social and religious prescriptions or interdictions, the master clarifies what the inner comportment of a yogi should be: every action, even the most humble, serves as an uninterrupted opportunity for consciousness of the Self, taking the place of prayer. Whatever crosses his mind: this is his meditation.
To reel about, drunk in the excess of divine grace: this is the mystic attitude par excellence. The offering of all things to the Lord and to him alone: this is true sacrifice. The offering of the differentiated world into the fire of Bhairava consciousness: this is oblation. [offering] To perceive the equality of all things: such is his most perfect wish and an intense reflection on his own Essence, the true yoga.
The master further transmits to the initiate the potent formulas (mantras) and makes the energy (kundalini) rise within him. Finally, with the aid of certain postures (mudras), he teaches him to equilibrate his internal experience – that of the Self – and his external experience – that of daily life (Ch. IV).
Communion of the Limited Being
With the path of energy, as we have just seen, discursive thought becomes purified under the power of discriminating intuition. The disciple attains the state of divine energy when knowledge manifests itself to him.
But as grace weakens, the ordinary man proceeds slowly by a roundabout path; the purification of thought then depends upon limited means. Master and disciple will have to work on the level of yoga and of knowledge. The guru is no longer necessarily a jnanin or a sadguru, a yogin suffices for the task. A simple instrument of grace, he transfers it with the help of mantras and the laying of of hands, thus imparting a philosophical and religious teaching directed to the sisya as a whole person.
The guru employs various means, of which the highest is meditation. We will mention elsewhere the breath's rising upward, a process which awakens the vital force (pranakundalini), as well as numerous forms of initiation.