H.P. Blavatsky’s major work was The Secret Doctrine (SD), which, according to one of her Masters, was the triple production of Mahatma M., HPB (H.P. Blavatsky), and Mahatma KH.  While it was being written, she was seriously ill and her life was in peril, but the Masters must have considered this book a very important one, for they kept her alive, in the midst of pain and suffering, in order to leave this legacy to humanity.
In its original form the SD consisted of two large volumes, yet HPB said she had prepared a Third Volume and was working on a Fourth, but she died before publishing these. Six years after her passing, her disciple Annie Besant published the Third Volume and, although some people claimed this was a spurious one, later investigations made by Daniel H. Caldwell showed that much of its material was actually the real Third Volume intended by HPB.  The promised Fourth Volume was to be almost entirely devoted to practical Occult teachings, although its publication, according to HPB, depended entirely upon how Volumes I and II would be received by Theosophists. Unfortunately, this Volume was never published.
The SD is frequently taken as a theoretical compendium of metaphysical and abstruse teachings, or as an ‘esoteric’ history about the genesis of the Universe and Man. In that context, this work can be studied as an exposition of some essential facts related to the Cosmos, Humanity, and the general plan for their development according to certain immutable laws. This conception has its own value, because it provides a deep and comprehensive cosmovision of existence. However, since the study of this subject is frequently reduced to a mere intellectual exercise with little impact on our daily life, one wonders if a book considered so important by the Mahatmas and HPB should not have a greater practical significance. In fact, in a letter to A.O. Hume, Master KH said:
The truths and mysteries of occultism constitute, indeed, a body of the highest spiritual importance, at once profound and practical for the world at large. Yet, it is not as a mere addition to the tangled mass of theory or speculation in the world of science that they are being given to you, but for their practical bearing on the interests of mankind. 
Therefore, the truths of Theosophy must have a real (practical) meaning for humanity. It is our duty as members of the TS to discover the real dimension of the SD (and all theosophical teachings), not as a collection of concepts, but as a transforming force in our lives.
Signposts on the Path
According to HPB, the SD has different keys of interpretation: metaphysical, astronomical, physiological, psychological, and so forth. Therefore, we will attempt here to consider these teachings from a psycho-metaphysical point of view, as HPB would say, looking for an interpretation that allows us to make them part of our spiritual practice.
In a talk with some students, HPB is reported to have said: ‘TRUTH lies beyond any ideas we can formulate or express’,  and ‘no picture will ever represent TRUTH’.  In another context, J. Krishnamurti (J.K.) also said: ‘The unknown, the limitless, cannot be captured by thought.’  Every authentic spiritual tradition or teaching states that Truth ‘is beyond the range and reach of thought’. If this is so, how can the Truth be realized? Maybe the question arises because we are used to considering thought as our only tool, although according to Theosophical teachings, this is not the case. HPB wrote:
The INFINITE cannot be known to our reason, which can only distinguish and define; but we can always conceive the abstract idea thereof, thanks to that faculty higher than our reason — intuition, or the spiritual instinct. 
The text is referring to buddhi, or Spiritual Intuition, which is the faculty we need to awaken for the perception of Truth. If the modern presentation of Theosophy has the object of guiding us to this goal, it must provide us with tools to help us make operative this ‘power latent in man’ through which spiritual realities can be grasped.
Thus Mme Blavatsky denied that the real value of the SD is to furnish a complete philosophical account of existence, and advised: ‘Come to the SD without any hope of getting the final Truth of existence from it, or with any idea other than seeing how far it may lead TOWARDS the Truth.’  She said that this book is ‘a means of exercising and developing the mind never touched by other studies’,  and the right work on it is ‘what the Indians call Jñâna Yoga’.  Therefore, the information given in the SD is not an end in itself, but a means. As JK said, ‘the word is not the thing’, and this book was written just ‘to provide him [the student] with signposts on that Path’.  When the student works rightly with the SD, it may lead him beyond the mental processes, where the light of Intuition may shine. This is what HPB points out in the Proem when she wrote: ‘Indeed, it must be remembered that all these Stanzas appeal to the inner faculties rather than to the ordinary comprehension of the physical brain’. 
One important thing to bear in mind when engaged in theosophical study is the concept of learning. In the present time, we tend to consider learning as the intake of new information from outside, and therefore we think we know Theosophy because we have collected concepts from different books and memorized them. But this knowledge mostly affects only the surface of our being; therefore, there is a gap between theory and practice. The real learning, as Plato stated, comes from within, and the Stanzas try to awaken this inner knowledge, which may be what is sometimes called ‘the archetypes in our deeper mind’. This knowledge is more comprehensive and has a transformative effect upon us.
Awakening Spiritual Perception
We should be serious in examining what are the bases for awakening our spiritual perception. As we have said, the mere recollection of the information given in the SD is not enough, and we should not imagine that spiritual perception will be awakened in some obscure way simply by reading. To reach this ‘deeper mind’ is not so easy and there are several factors involved in it, as expressed in theosophical literature.
HPB says that Intuition arises in ‘a state in which one ceases to be the conditioned and personal “I”, and becomes one with the ALL’.  This is also the very core of JK’s teachings, since he was primarily interested in helping us transcend all activities of our brain consciousness (kâma-manas). In one of his dialogues with Dr David Bohm, he differentiates between the Mind, which is universal and unconditioned, and the brain, which is limited. And he says that the brain is the basis of the self, while the Mind is the source of the highest form of intelligence. But then the question arises: how can that Mind act through the brain? According to JK this is possible only when there is no sense of separateness:
DB: You are using the word Mind; not ‘my’ Mind.
JK: Mind. It is not ‘mine’.
DB: It is universal or general.
JK: Yes. . . .
DB: It would almost seem to imply, then, that in so far as a person feels he is a separate being, he has very little contact with Mind.
JK: Quite right. That is what we said. 
So, both HPB and JK established the necessity of leaving the ‘self’ behind as a basic condition for awakening Intuition. Obviously, this breaking of that sense of separateness is not something that can be achieved taking a single course of action; all the different aspects of our life have to be orientated towards this aim, but here we will concentrate on how the SD can help us in this task.
First Fundamental Proposition
The Fundamental Propositions given in the Proem of the SD contain statements about the essential nature of the Cosmos and, at the same time, Mankind, which is a mirror of the Universe. As HPB wrote:
As above so it is below, as in heaven so on earth; and man — the microcosm and miniature copy of the macrocosm — is the living witness to this Universal Law and to the mode of its action. 
Therefore, proper study of cosmic processes from an esoteric point of view can have a direct impact upon us in a variety of ways. We will attempt now to examine these Fundamental Propositions, not in full length or in all their connotations, but highlighting certain aspects useful for a psycho-metaphysical interpretation.
The first one establishes that there is a ‘ground’ on which and through which the Cosmos is manifested. It is:
An Omnipresent, Eternal, Boundless, and Immutable PRINCIPLE, on which all speculation is impossible, since it transcends the power of human conception and could only be dwarfed by any expression or similitude. It is beyond the range and reach of thought — in the words of the Mândukya [Upanishad], ‘unthinkable and unspeakable’. 
At first glance, it seems nonsensical to teach something on which all thinking or speculation is impossible; therefore some say it is useless to study that Absolute Principle, even though it is a Fundamental Proposition of Theosophical teachings. On the other hand, people who try to deal with this subject frequently reduce it to a mere philosophical postulate about that primordial Unity in which illusory diversity takes place. But taking into account the fact that many pages in the SD are dedicated to this Absolute Reality, there must be another reason for writing about this ‘unthinkable and unspeakable’ Principle.
This First Proposition and Stanza I in the first volume of the SD refer to the unmanifested state of the universe, where there is only infinite space and eternity in an absolute state. According to HPB, right meditation (not merely intellectual study) upon this concept may have an important effect upon the mind. She recommended this exercise as the very foundation for practising herDiagram of Meditation, when she said: ‘First conceive of UNITY by expansion in Space and infinite in Time.’  This statement suggests that we expand the mind; but why? This is in order to abolish self-centredness and lose the sense of time. As JK repeatedly mentioned ‘the notion of time is based on thought’, and we find that in that state of universality and eternity the mind becomes still and quiet, without images to work with. Later in her Diagram, HPB says that the normal state of our consciousness must be moulded by: ‘Perpetual presence in imagination in all Space and Time.’ This could seem a mere fantasy, but the Diagram points out that doing this will produce a change upon the consciousness:
From this originates a substratum of memory which does not cease in dreaming or waking. Its manifestation is courage. With memory of universality all dread vanishes during the dangers and trials of life.
This last concept is quite evident because if we look inside ourselves, we will see that fear comes from the sense of separateness, the identification of our consciousness with this mortal, small self, and this type of work helps us diffuse it. We find a similar statement in Light on the Path:
Live neither in the present nor the future, but in the Eternal. This giant weed [of self] cannot flower there; this blot upon existence is wiped out by the very atmosphere of eternal thought. 
Then, establishing our consciousness in a state of universality and eternity (which is quite different from talking about it) helps us to leave the self behind, and then there is the possibility of being in rapport with the unconditioned. Let us consider it from another angle, as in the dialogue quoted above between JK and Dr Bohm:
DB: What is the nature of the Mind? Is the Mind located inside the body, or is it in the brain?
JK: No, it is nothing to do with the body or the brain.
DB: Has it to do with space or time?
JK: Space — now wait a minute! It has to do with space and silence . . . .
DB: Now I would like to go into the question of how they are making contact.
JK: Ah! Contact can only exist between the Mind and the brain when the brain is quiet . . . .
DB: And one can see that if the brain is quiet it could listen to something deeper?
JK: That’s right. Then if it is quiet, it is related to the Mind. Then the Mind can function through the brain. 
Therefore, the correct meditation upon the First Fundamental Proposition, which points out a Reality beyond thought, may steer us to a condition of silence and quietude, where the self is not, where Spiritual Intuition can arise.
Second Fundamental Proposition
However, we do not know how to proceed in that direction, being in the midst of a restless mind. The Second Fundamental Proposition gives us a clue. It affirms: ‘The Eternity of the Universe in toto as a boundless plane, periodically “the playground of numberless Universes incessantly manifesting and disappearing”.’
From a macrocosmic point of view, the Universe in toto (the Space) is eternal and boundless, but there is periodically an incessant movement of manifestation and dissolution taking place within that immutable Space. The ‘numberless universes incessantly manifesting and disappearing’ in the Macrocosms would correspond in the Microcosms with our feelings, thoughts, memories, and so on, which are constantly arising and coming to an end. Following the sequence of these two Fundamental Propositions at first we must have, as far as possible, an ‘unconditioned’ perception, and then deal with the conditioning within. This progression is closely related to the Diagram of Meditation mentioned above, where HPB says that after conceiving the Unity we have to meditate on our states of consciousness. Why are we exhorted to do this? Perhaps this is a strategy to meditate ‘upon one’s lower self in the light of the inner divine man’  and not as a mere intellectual analysis done by the conditioned mind. Here, we are looking at our normal movement from the highest state we are able to reach. This also resembles JK’s answer to a question. When asked how we can build a bridge between our conditioned state and That which is unconditioned, he replied that it is impossible. The bridge has to be built from That to this. Of course, this does not mean that we have to delude ourselves, taking for granted that the thinker is different from the conditioning. The (lower) mind, the self, isthe conditioning. But the (silent) faculty of perception is not inevitably limited to the brain consciousness, to the self. So, what is required here is for the perception to detach itself from the ego-sense and from identification with psychological processes, which is done through that sense of ‘being the space’.
To examine this more closely, each one experiences an incessant movement of sensations, feelings, thoughts, memories, expectations, and desires, in succession. Although nothing in this movement is permanent, somehow we attach to it a sense of being a single identity, ‘the thinker’, to whom all this occurs. But we do not realize that all these processes take place mechanically: there is ‘something’ in us that thinks or feels as a response to external or internal stimuli, or, in other words, those processes are merely the activity of skandha-s.  However, identifying ourselves with that inner movement, we say ‘I am he who is thinking or feeling’. But this perception is mistaken, because there is no thinker as a separate entity. If we observe silently, we may realize there are only different thoughts, each one assuming the role of the ‘thinker’ when active, with memory connecting all the passing thoughts, thereby creating a sense of continuity. But then, what is permanent? As mentioned earlier, it is ‘the space’. This means that in the attempt to raise the consciousness from the impermanent to the Eternal, we have to identify ourselves with the (inner) immutable space in which the psychological processes are taking place, that is, with that which contains all movements, and not with the movement itself. As Sri Sankarâchârya says:
Space is not affected with the smell of wine by contact with the jar, and in the same way one’s true nature is not affected through contact with the things one identifies oneself with. 
One should become aware of oneself, indivisible and perfect like Space itself, when free from identification with such things as one’s body, senses, functions, mind, and sense of doership, which are all the products of one’s own ignorance. 
This suggestion is not an abstraction or imagination created by thought. When one is actually watching very quietly the inner movement and loses the sense of ‘me’, at least for the time being, there is a feeling of being just the space which embraces the psychological processes. And this state may be considered as one of pure ‘Self Existence’ because there is no sensation of ‘I am this or that’, but one of pure ‘Be-ness’, simply a sense of identity without any demarcation.
And there is something interesting in this process: we begin trying to put ourselves in the position of being the Space, being the Witness of all that happens inside us, and finish in that condition of being the silent and quiet pure space. This resembles the famous statements of JK: ‘The first step is the last step’, or ‘freedom (from the conditioning) has to be at the very beginning’. In classical Theosophical literature we find similar concepts when it is said that the Path (the means) and the Goal are essentially one and the same.
Third Fundamental Proposition
Finally, the Third Fundamental Proposition gives us a hint as to the correct attitude towards daily experiences. It establishes:
The fundamental identity of all Souls with the Universal Over-Soul, the latter being itself an aspect of the Unknown Root; and the obligatory pilgrimage for every Soul — a spark of the former — through the Cycle of Incarnation, or ‘Necessity’, in accordance with Cyclic and Karmic Law . . . [in order to] have an independent (conscious) existence.
This Proposition affirms that we, as a consciousness, are essentially the Universal Oversoul, that is, the Universal Mind. However, we have to live through these particular vehicles (the physical, emotional, and mental bodies) which limit that Universal Consciousness in order to acquire a pure self-conscious existence. Therefore, we cannot refuse to go through all experiences in life, irrespective of their being pleasant, painful, or neutral, and these experiences may not be of much use unless we go through them with a certain attitude. The Voice of the Silence says:
The seeds of Wisdom cannot sprout and grow in airless space. To live and reap experience the mind needs breadth and depth and points to draw it towards the Diamond Soul. Seek not those points in Mâyâ’s realm; but soar beyond illusions, search the eternal and the changeless SAT [the one eternal and absolute Reality and Truth, all the rest being illusion], mistrusting fancy’s false suggestions. 
Human beings change very slowly because, although we are alive, we are not experiencing life to the fullest. We usually act mechanically, inattentively, and moreover, identify ourselves with the personality, selecting pleasant experiences while rejecting those which are painful. Consequently, we learn very few lessons from them. But ‘to live and reap experience’ our mind needs ‘breadth and depth’, that is, it needs to be open, vulnerable, void, not engaged in all the psycho-physiological processes and reactions. It needs rather to be a Witness, and this is possible only if our consciousness is not confused with Mâyâ’s realm, ‘hearing fancy’s false suggestions’, but is pointed towards ‘the eternal and the changeless SAT’, the immutable Space or Be-ness, as previously discussed. In this way, the Fundamental References Propositions can be seen as a spiritual practice, showing us what kind of attitude we should have while living our daily lives to really ‘reap experience’.
Those interested in this subject will find it useful to consult HPB’s Diagram of Meditation, which has further suggestions to complement this practice.
The Theosophist, May 2006
 Letters from the Masters of the Wisdom, Second Series, No. 69.
 Daniel H. Caldwell, ‘The Myth of the “Missing” Third Volume of The Secret Doctrine’, Blavatsky Study Centre, online ed., 2004, http://www.blavatskyarchives.com/sdiiipt1.htm
 The Mahatma Letters to A. P. Sinnett, in chronological order, No. 12 (ML-6), 10 Dec. 1880.
 How to Study Theosophy, Robert Bowen, (1997) TPH Adyar, p. 8.
 Op cit, p. 13.
 The Future of Humanity, First Conversation, Brockwood Park, 11 June 1983.
 ‘The Beacon of the Unknown’, H. P. Blavatsky’s Collected Writings (CW), XI, p. 258.
 How to Study Theosophy, p. 9.
 Op cit., p. 9.
 Op cit., p. 13.
 Op cit., p. 14.
 The Secret Doctrine (SD), I, 2003, TPH Adyar, 3-vol. ed., p. 21.
 ‘The Beacon of the Unknown’, CW, XI, p. 258.
 The Future of Humanity, Second Conversation, Brockwood Park, 20 June 1983, pp. 71-3.
 SD, I, p. 274.
 SD, I, p. 14.
 The Theosophist, May 2003, pp. 308-9.
 Light on the Path, 2000, TPH Adyar, p. 20.
 The Future of Humanity, Second Conversation, pp. 62, 67.
 SD, V, 1962, TPH Adyar, 6-vol. ed., p. 468; or CW, XII, p. 603.
 Psychic ‘aggregates’ of habits and tendencies.
 Viveka-chudâmani (The Crest-Jewel of Discrimination), v. 450.
 Op cit., v. 384.
 The Voice of the Silence, v. 114.