Every being or thing throughout the universe, and indeed the universe itself, has, or rather is, its own auric egg. Its primal substance is the akasa of which the cosmic ether is the grossest aspect. This akasa concretes itself progressively from its highest to its lowest part, so that the auric egg in its most material aspect is but slightly more ethereal than the physical body, and is in fact astral substance. It is fundamentally life; it is not only the seat of the pranas or life-forces, but the auric egg is itself concreted life, for akasa is life, and life is akasa.
The auric egg originates in the monad which is its heart or core, and from which, when manifestation begins, it emanates forth in streams of vital effluvia. On the different planes which the auric egg traverses as a pillar of light, from the atmic to the physical, each such auric or pranic effluvium is a principle or element, commonly reckoned in man as seven in number. When the auric egg is viewed on any one plane of the human constitution, we discover that this plane or 'layer' not only corresponds to, but actually is, one of the unfolded six principles of man; it would appear to be ovoid or somewhat egg-shaped in outline, and to be a more or less dense, extremely brilliant, central portion surrounded by an enormously active interworking cloud of pranic currents. If we look at the sun we get a sublimely beautiful picture of what the solar auric egg is on this plane, and this gives some idea of what the auric egg of a human being looks like when considered on any one of its six planes or layers emanated from the atmic or monadic source.
These immensely active and interworking clouds or vital effluvia are actually the pranas of the auric egg on any one plane expressing themselves as auras. Thus, in illustration, all the pranas in and of man's astral-physical body are simply the vital auras of his physical being, and similarly so on any other layer of his constitution.
The auric egg, originating in the atman or the true naked monad, flows forth from the heart of the monad, clothing itself first in its highest veil, the substances and energies of buddhi. As the consciousness stream descends farther into manifestation, the buddhic auras with the atmic energies working in and through them produce manas, the second veil or garment; and this in its turn flows forth in the next auric attribute, the kama, including its various substances and forces, until finally the physical body is formed from the matters and forces of the astral auric egg as its lees or dregs.
Each such layer or plane of the stream of consciousness called the auric egg is emanated from a center or core which itself is a child monad emanated from its superior, and so on upwards until we reach the atmic monad again, out of the heart of which all flows. Thus, each of these children monads aids in producing in its fullness the whole auric egg of a septenary being, by pouring forth from within its heart the particular swabhavic pranic essences belonging to itself as a monad on that plane.
All manifestations of human life, from gestation to death, originate in the auric egg, and pass out through the physical body. Every part of the body, every different organ, is a deposit from an equivalent layer of the auric egg. Blood, as an illustration, is the physical representative of what in the auric egg manifests itself as the vital streams. It is concreted or materialized vitality, and the various cells with which it is filled represent on this plane the as yet unevolved life-atoms which exist equivalently and causally in the auric egg. Just as blood is the dregs of the pranic streams flowing through the auric egg, so is the physical brainstuff the dregs of the manasic substance which composes a part of the auric egg, i.e. a deposit from those layers of the auric egg in which the manasic principle functions.
Mentality thus originates on the mental plane of the auric egg, spiritual thought and impulses on the spiritual planes, animal impulses on the grosser planes. The astral body has its source in the auric egg also; and even the physical body is a deposit of it, being but the shell of the auric egg — born out of it, built up from its life, and deriving therefrom all its vitality.
It is through their auric egg that the spiritual adepts (and even the Brothers of the Shadow) perform the wonders which they can work, for it is the center of their vitality. An adept in these mysteries, by the power of will and by wisdom, could surround himself with a cloak of invisibility — a concealing veil of part of his auric substance — so that he could pass through a crowd in broad daylight, and be totally unseen. Again, he could so harden or strengthen his auric egg as to cast around himself an impenetrable garment that nothing known to man could pierce. Neither bullet nor sword could pass this protecting veil of akasa, which nevertheless is so ethereal that it is utterly invisible. And yet, because it is composed of pure energy, it is the same, fundamentally, as pure substance. The atoms composing the bullet or the sword are unable to penetrate it, for to those atoms this protecting veil is made incomparably denser by the strength of will of the one who so shields himself, or someone else. It is by a knowledge of the powers and energies latent and residing in the auric egg that an adept, by using his will, can also levitate himself or, on the other hand, make his body so heavy that fifty men could not lift it.
The size of the auric egg is not always the same. When it is in full manifestation, the pranic essences poured forth from the different centers are greater than when it is in a state of inactivity. Thus, after death, the auric egg — otherwise the constitution — shrinks very considerably as concerns the reach of the pranic auras, and this is especially the case in its lower layers, which break up into their component atoms and are dissipated. In fact, mere size or extension of an auric egg has nothing to do with the intrinsic functions of consciousness; for when a monad is in certain spiritual states, as happens after death, the extent of the pranic or vital outflow may be at times infinitesimal in character. This, however, does not apply with equal force to the spiritual and divine layers of the auric egg, for these, being relatively immortal, are not affected in any especial degree by the death of a being such as a man.
Thus we see that the auras of a man's astral-physical body are merely those portions of the pranas which during incarnation surround the body as a mist or shining cloud; and these auras are invariably characterized by marvelously shifting and changing scintillations and flashings of color.
In principle, then, the higher the layer in the auric egg the farther-reaching are its various pranic auras, so that actually the higher layers are characterized by auric extensions which range far beyond the limits of our own planetary chain, to the sun and other planets — indeed, the reach of the auric egg in its divine aspects embraces in varying degrees of power and largeness different parts of the galaxy. It is just by these 'touchings' or 'contacts' of the auras of the different layers that we interweave our vitality with the beings and things that surround us, and this on all planes of our constitution. And herein lies the cause of the ordinary sympathies and antipathies that we are constantly experiencing: our pranic auras touch or contact the world around us, enabling us to become cognizant of our environs by means of our sensory apparatuses both outer and inner.
As a matter of fact, no entity could cognize any other entity in the universe unless his auric egg reached that entity. We could not see the stars unless our auric egg were already there, and transmitted to us along the pathways of the ether the touch that we have of those distant objects. There is actually no such thing as action at a distance, to quote the favorite phrase of the scientists of our grandfathers' day. All things are connected together everywhere, not merely those that are in the vicinage of each other. Every human being is as closely and straitly allied with Sirius or with the Polar Star as he is with his own skin, and his divine essence extends even farther.
The sun, for example, may be said to 'feel' and to 'embrace' whatever is contacted by its rays flashing forth from itself; and it is precisely the intellectual and spiritual and divine reach of the forces and energies of the auric egg of the solar chain, linking themselves in eternal and unbreakable bonds with the surrounding galaxy, which thus permits the solar chain to come into contact with the galaxy, its home. Indeed, the reason that one man can understand another is that the manasic layers of the auric egg of the one touch and interweb with those of the other, thus bringing about intellectual contact; and when there is such synchrony of vibration, we have intellectual sympathy and understanding; but when the manasic wavelengths are not of the same frequency, we have the cases of inability of men to understand each other, antipathetic feelings, etc.
However, let us not be too literal and falsely imagine that here is a reason for indulging in hatreds as being 'according to natural law,' or some other such tommyrot. Of course, we should try to synchronize our 'vibrations' with those of others — not by descending to a lower level than our own best, but by endeavoring through impersonal will and spiritual aspiration to apply the grand old rule of cosmic ethics that love harmonizes all things, that hatred is always destructive. It is our duty to replace antipathies by the sympathies that we can in fact always attain to by rising to higher planes of feeling and thought. This is possible because all monads, in their own high status, are permanently on the plane of spirit, and hence vibrate in harmonic and synchronous spiritual rhythms.
No sensitive man can go into a crowd without being strongly affected by its emanations — an efflux of vitality which leaves every human being constantly, day and night — and these emanations literally poison the outer layers of the auric egg. However, help is afforded by nature's automatic closing of the doors of entrance, and thus the auric atmosphere receives protection. Just as the pores of the skin involuntarily close and open — a process which aids in keeping the body healthy and in preventing the entrance of disease — so are there certain psychic adjustments, automatic in type, which take place in one's auric atmosphere when in crowds.
Now if one were strong enough in love and in universal sympathy, as the higher adepts are, he could enter safely into places heavily charged with the emanations of matter and evil, and do so with perfect security to inner health, because his auric egg, on account of its innate purity, would then automatically close its 'pores' against such emanations; the heart and the mind meanwhile expanding in compassionate understanding so largely as to see hid beauty and to sense natural sympathy even with one's most uncompromising foe, because we are all united on the higher planes of our being.
From the foregoing, we can see the reason for H.P.B.'s statement (The Key to Theosophy, p. 176) to the effect that the pranas are the direct emanations from an atmic layer of the auric egg, and similarly so from the atmic essence of the different children monads in the human constitution. Furthermore, it is the auric egg as a whole which is the actual ever-enduring compound vehicle of man considered as a peregrinating entity. It is in his auric egg, in its many and various planes or layers, that a man throughout eternity lives and moves and has his consciousness, and all the other attributes and faculties and powers that characterize him in any one of the many episodes of his immensely long evolutionary journey.
In connection with this last thought, we should remember that the size of the auric egg is of no importance, because during incarnation it is variously extensive, while after death its pranic auras may all be withdrawn into the heart of the different monads from which they originally emanated. Thus, on any one plane, such as the astral-physical, the auric egg may be infinitesimal in extent, possibly even smaller than an anu or an atom; and at the same time in its spiritual and divine reaches coextensive with the universe. This explains the phrase in the Upanishads which describes Brahman as "smaller than the atomic, vaster than the universe."
(From Sunrise magazine, April/May 2001. From Fountain-Source of Occultism, copyright © 1974 by Theosophical University Press)