All forms, from atoms to men, that give expression to life in their way, come into being, then disintegrate, but the Life remains. Although for purposes of study we divide the field of Esoteric Science into various aspects, it must constantly be reaffirmed that the aspects are facets of a UNITY. Everything in the universe, visible and invisible, is, was, and ever will be one absolute essence, from which all starts, and into which everything returns.
All existence is ONE THING. This ONE THING is variously called the One Life, the One Reality; it is the source of Being, and of all beings; it is in everything - in fact, it is everything, for there is nothing else. ... the root of all nature, objective and subjective, and everything else in the universe, visible or invisible, is, was and ever will be one absolute essence, from which all starts, and into which everything returns ...The Key to Theosophy III, 43 In all subsequent study, this fundamental fact must never be lost from sight; all forms that come into being, from atoms to men, are animated by the same Life; the forms disintegrate, the Life remains. We human beings are one with it; our life is that Life. Explaining how Theosophy views "God, Soul and Man", Mme Blavatsky states: In their origin and in eternity, the three, i.e. God, the soul and man, like the universe and all therein, are one with the absolute unity, the unknowable deific essence ... The Key to Theosophy VI, 83 Although for purposes of study we divide the field of Esoteric Science into various aspects, it must constantly be reaffirmed that the aspects are facets of a UNITY. The moment one lets this idea slip from the mind, "... (and it is most easy to do so when engaged in any of the many intricate aspects of the Esoteric Philosophy) the idea of SEPARATION supervenes, and the study loses its value". The Bowen Notes , 9
For a further exploration of Unity: 'What Theosophy Is' Basic Propositions & Questions
The universe and all that is in it are subject to a timeless process described as "Days and Nights", alternating periods of activity and rest. According to the occult teaching, there is no creation, in the sense of something being made out of nothing. There is indeed nothing new under the sun.
We believe in no creation, but in the periodical and consecutive appearances of the universe from the subjective on the objective plane of being. at regular intervals of time, covering periods of immense duration. 
There is therefore nothing that can properly be called a beginning, for what is commonly called creation is only the periodical re-emergence of things - forms or entities - which already existed. With the coming of night, every-thing seems to disappear , merged into a uniform darkness; as the sun rises, all things once more reappear - temporarily, just as their disappearance had been temporary. The time-scale may vary from the few hours of life of an insect or the three-score years and ten of the life of man to the almost incalculable duration of a sun or a universe. Nevertheless, whether the periods be long or short, the alternation remains, a manifestation of the universal law of periodicity.
One of the esoteric keys to the understanding of life is analogy, as given in the Hermetic axiom, "As above, so below". The universe is the macrocosm, the great ordered whole, and man is its miniature reflection, the microcosm. Our experience of ourselves shows us that, as human beings, we function in a variety of ways, in physical action and in such modes of consciousness as thinking, feeling and dreaming. Esoteric Science teaches that these modes of consciousness occur at different levels, from the sensory or objective to the deeply inner or subjective. Furthermore, these levels themselves are a reflection, in the individual, of universal planes of being: just as individual physical action takes place on the physical plane, using the material of that plane, so mental activity - thought - takes place on the mental plane, using the material of that plane. There are, according to Esoteric Science, seven such planes in Nature, and similarly there are seven states of consciousness in man, in which he "can live, think, remember and have his being" The Key to Theosophy VI, 89
For a further exploration of this topic: 'What Theosophy Is' Man's Nature
The Scriptures and religious traditions of all cultures make frequent reference to non-human entities, variously termed Angels, Devas, Gods, Spirits of one kind or another. In mythology these beings appear as Nature-spirits, Fairies, Sylphs, Salamanders, to name but a few. Esoteric Science supports universal tradition in affirming that the different planes of Nature are peopled by hierarchies of beings, each with characteristic properties and modes of functioning. In the Bible there are well-known instances of angelic appearances, singly as "the angel of the Lord" or as "a multitude of the heavenly host". The "thrones, dominions, principalities and powers" mentioned several times by St Paul are terms well recognized in angelology for some of the non-human hierarchies. Everywhere in Nature there is life, manifesting through infinite gradations of individual lives, for there is neither empty space nor inanimate matter anywhere in the universe.
Elementals is the term used to refer to beings who are beginning a course of evolutionary growth, and who thus are in the elemental stage of development. In general the term refers to beings who are below the mineral kingdom in the evolutionary scheme. Their existence is universally recognised in folklore under such names as fairies, elves, gnomes and suchlike, a mentioned earlier. But they are best understood as forces in Nature rather than as beings having miniature or ethereal human shapes.
These are examples of the hierarchical structure of the Cosmos. The Elements, in Esoteric Science, are seven in number, the four familiar ones of Earth, Air, Fire and Water, to which it adds a semi-material Ether that is still invisible to us, and two others which are "as yet absolutely beyond the range of human perception" The Secret Doctrine I ,12 /I, 40 /I, 78 Yet all of these, it must always be remembered, are aspects of the One Universal Element, the source of all objective existence.
These seven elements with their numberless Sub-Elements ... are simply conditional modifications and aspects of the ONE and only Element. Wisdom of Solomon (Apocrypha)
It is apparent even to superficial observation that the universe operates according to Law. All our sciences and technologies are based on the recognition of this fact. This law is not imposed from outside but is the very nature of the Cosmos. Fundamentally it is the law of cause and effect, action and reaction, by which the Cosmos as a whole, and all its parts individually, are ordered and regulated. The Law is in itself Wisdom, Intelligence and Power; it is the Wisdom that "mightily and sweetly ordereth all things" Wisdom of Solomon (Apocrypha) operating through the Hierarchies of beings by which the Cosmos is made and maintained as one harmonious whole.
For a further exploration of Universal Law: Universal Law
Here there is introduced a teaching that goes far beyond anything known to today's sciences. Although not easy to grasp at first, it will be found to throw much light on areas of experience at present little understood even by psychology, for example, the mystical and psychic.
It has been stated (in paragraph 4 above), that there is no such thing as empty space in the universe. Esoteric Science teaches that the entire Cosmos is pervaded by Akasha, primordial substance, or rather the noumenon - the non-sensuous reality - beyond substance. In the Theosophical Glossary, Akasha (from a Sanskrit word meaning "brilliant" or "luminous") is described as "the subtle, supersensuous spiritual essence which pervades all space". This primordial substance differentiates into all the forms of matter, those of the invisible as of the visible regions of the universe. Hence the definition of Akasha as "the Universal Soul ... from which all that exists is born by separation or differentiation. It is the cause of existence; it fills all the infinite Space".
The lowest region of Akasha, immediately above the gross physical plane, is termed the Astral Light. It is "the invisible region that surrounds our globe" and everything in it, and corresponds to the subtle vehicle or "double" in man, the linga sharira. In it is impressed indelibly everything that takes place in the physical, psychical and mental realms. It is thus the storehouse of memory, both in the Cosmos and in mankind.
In the study of the constitution of man according to Occultism, two aspects of his inner nature are recognized, one mortal the psyche or soul, and the other immortal the spiritual essence. (In everyday parlance, and in much religious usage, the words "soul" and "spirit" are used loosely and often interchangeably. Particular attention must be paid to the precise meaning attached to them in the present study.) The spiritual essence in man, a persistent entity, attaches itself periodically to a succession of personalities which it projects into the objective world. In so doing, it obeys the universal cyclic law that operates throughout Nature. The temporary personality comprises a complex mortal non-physical component, the psyche or soul, housed in a body of flesh.
It will be seen that rebirth, or reincarnation, is not a peculiarity of mankind; it is a particular instance of that law of alternation of activity and rest that may be observed in the natural world - the cyclic process of birth, growth, decay and death of the form, and the persistence of the life through successive forms.
For a further exploration of this topic Reincarnation
The preceding section states that in the life of man there are alternating periods of activity and rest, or, more precisely, periods of incarnation that is, life in a body of flesh alternating with periods of discarnate existence, analogous to the twenty four hour cycle of wakefulness and sleep. Earlier, some information was outlined concerning the seven planes of Nature and the seven states of consciousness. Incarnation is the process of assuming vestures or vehicles through which consciousness can function in the lower planes; death is the process of withdrawal from these vestures. It must already be evident to the student that every aspect of Esoteric Science is inextricably related to every other aspect. To understand death and the after death states, one must study the sevenfold constitution of man and cosmos, and this must lead to or be preceded by the study of Akasha and the Astral Light. Nevertheless, whatever aspect is being considered, it must be seen as part of a whole, the functioning of which, in all its parts, is subject to universal law. At every stage of the study it is necessary to remind oneself of these facts.
For a further exploration of this topic After Death
Evolution is the emergence of the possibilities inherent in Nature from latency into active expression. The word means, literally, unfolding, and it implies the prior process of involution by which the potentialities of spirit are communicated to matter.
Esoteric Science affirms the universality of the evolutionary process:
The whole order of nature evinces a progressive march towards a higher life. There is design in the action of the seemingly blindest forces. The whole process of evolution with its endless adaptations is a proof of this. The Secret Doctrine I, 277 /I, 297 /I, 320
Here we must return to the Hierarchies of Sections 4 and 5, for the evolutionary process is not a mechanical one but is "guided, controlled and animated by an almost endless series of Hierarchies of sentient Beings." The Secret DoctrineI, 274 /I, 295 /I, 317
Much confusion is caused by the ignorant association of the word "spiritualistic" with the word "spiritual". What are commonly called spiritualistic phenomena are in fact psychic phenomena, that is, phenomena explicable in terms of the lower levels of the next plane, little removed from the physical world perceived by the ordinary senses. For the most part, this physical world is the only one of which we are aware, because we do not possess faculties responsive to stimuli on higher planes. In some people mediums and sensitives psychic faculties are more or less developed, enabling them to hear and see things of which others are not aware. However, there is nothing spiritual in the possession of such faculties, unless they have been brought under the control of the will of the individual; such conscious control alone can properly be termed spiritual, for it is a manifestation of the awakened power of the essential man, the Spirit.
These are the terms used to indicate states in the great evolutionary cycles. In our cosmic scheme, they are applied particularly to our Earth and its humanity. Like everything else in Nature, planets have their period of activity and rest, their days and nights, analogous to human life and death. A grand evolutionary programme is in operation throughout the Cosmos, each part of which whether it be planet or kingdom of nature or human group has to pass through sequential phases of development towards its particular goal.
In the study of the programme for humanity, it will be important to note that the term "Race" indicates a stage in the evolution of humanity consciousness. It applies to the development of mental and psychic faculties as well as to the superficial physical characteristics such as skin colour or hair type.
If examined in the light of Esoteric Science this term appears to be a misnomer. Mankind is a stage in an immense journey, the pilgrimage of "the Many to the Everlasting One." The Meaning of Man, by Clifford Bax The object of the journey is the realization of the essential unity of life, the experience of the One consciousness which pervades the whole. The development is in effect the increase in the responsiveness of living instruments, so that the consciousness of the individual becomes identified eventually with, or merged into, that of the other units of humanity who have transcended the limitations of purely personal existence.
Human life, with its vicissitudes and suffering, has appropriately been called a training ground, the school of life, in which the main lesson to be learned is the elimination of selfishness in all its forms. Selfishness, the "great dire heresy", is a denial of the fact of unity and will be seen as the source of many of the problems of mankind. Similarly, all that contributes to breaking down the walls of separateness - altruism, compassion, love - must promote the spiritual evolution of the individual and of the human race.
Various terms have been used to refer to the esoteric tradition, Theosophy. It is Esoteric Science , the Ancient Wisdom, the Secret Doctrine and the Wisdom Religion. But in using this last term, care must be taken not to see in it a religion comparable to Hinduism, Buddhism, Christianity or any other of the religions of man. The Wisdom Religion is the source of all of these, and the study of the similarities in their traditions, forms and doctrines will show that in essentials they must stem from a common origin.
One of the aims that Mme Blavatsky set before herself in The Secret Doctrine is particularly relevant:
... to rescue from degradation the archaic truths which are the basis of all religions, and to uncover, to some extent, the fundamental unity from which they all spring. The Secret Doctrine I, viii /I, xxi /I, 9
The state of religion today, the perpetuation of forms in ignorance of the truths they represent, shows the need for the wide dissemination of Esoteric Science if that aim is to be achieved.
Throughout the study of Esoteric Science, it should be recognized that what is presented to us here is not speculation or hypothesis but knowledge - knowledge possessed by men who, by the development within themselves of the necessary faculties, made themselves able to investigate at first hand the hidden side of Nature.
The Secret Doctrine is the accumulated Wisdom of the Ages, and its cosmogony alone is the most stupendous and elaborate system: e.g., even in the exotericism of the Puranas. But such is the mysterious power of Occult symbolism, that the facts which have actually occupied countless generations of initiated seers and prophets to marshal, to set down and explain, in the bewildering series of evolutionary progress, are all recorded on a few pages of geometrical signs and glyphs. The flashing gaze of those seers has penetrated into the very kernel of matter, and recorded the soul of things there, where an ordinary profane, however learned, would have perceived but the external work of form. But modern science believes not in the "soul of things", and hence will reject the whole system of ancient cosmogony. It is useless to say that the system in question is no fancy of one or several isolated individuals. That it is the uninterrupted record covering thousands of generations of Seers whose respective experiences were made to test and to verify the traditions passed orally by one early race to another, of the teachings of higher and exalted beings, who watched over the childhood of Humanity. That for long ages, the "Wise Men" of the Fifth Race, of the stock saved and rescued from the last cataclysm and shifting of continents, had passed their lives in learning, not teaching. How did they do so? It is answered: by checking, testing and verifying in every department of nature the traditions of old by the independent visions of great adepts; i.e., men who have developed and perfected their physical, mental, psychic, and spiritual organizations to the utmost possible degree. No vision of one adept was accepted till it was checked and confirmed by the visions - so obtained as to stand as independent evidence - of other adepts, and by centuries of experience. The Secret Doctrine I, 272 /I, 293 /I, 316