10 Main Points from “Isis Unveiled”
To comprehend the principles of natural law involved in the several 
phenomena hereinafter described, the reader must keep in mind the fundamental propositions of the Oriental philosophy which we have successively elucidated. Let us recapitulate very briefly:
1st. There is no miracle. Everything that happens is the result of law – eternal, immutable, ever active. Apparent miracle is but the operation of forces antagonistic to what Dr. W.B. Carpenter, F.R.S. – a man of great learning but little knowledge – calls “the well-ascertained laws of nature.” Like many of his class, Dr. Carpenter ignores the fact that there may be laws once “known,” now unknown to science.
2d. Nature is triune: there is a visible, objective nature; an invisible, indwelling, energizing nature, the exact model of the other, and its vital principle; and, above these two, spirit, source of all forces, alone eternal, and indestructible. The lower two constantly change; the higher third does not.
3d. Man is also triune: he has his objective, physical body; his vitalizing astral body (or soul), the real man; and these two are brooded over and illuminated by the third – the sovereign, the immortal spirit. When the real man succeeds in merging himself with the latter, he becomes an immortal entity.
4th. Magic, as a science, is the knowledge of these principles, and of the way by which the omniscience and omnipotence of the spirit and its control over nature’s forces may be acquired by the individual while still in the body. Magic, as an art, is the application of this knowledge in practice.
5th. Arcane knowledge misapplied, is sorcery; beneficently used, true magic or WISDOM.
6th. Mediumship is the opposite of adeptship; the medium is the passive instrument of foreign influences, the adept actively controls himself and all inferior potencies.
7th. All things that ever were, that are, or that will be, having their record upon the astral light, or tablet of the unseen universe, the initiated adept, by using the vision of his own spirit, can know all that has been known or can be known.
8th. Races of men differ in spiritual gifts as in color, stature, or any other external quality; among some peoples seership naturally prevails, among others mediumship. Some are addicted to sorcery, and transmit its secret rules of practice from generation to generation, with a range of psychical phenomena, more or less wide, as the result.
9th. One phase of magical skill is the voluntary and conscious withdrawal of the inner man (astral form) from the outer man (physical body). In the cases of some mediums withdrawal occurs, but it is unconscious and involuntary. With the latter the body is more or less cataleptic at such times; but with the adept the absence of the astral form would not be noticed, for the physical senses are alert, and the individual appears only as though in a fit of abstraction – “a brown study,” as some call it.
To the movements of the wandering astral form neither time nor space offer obstacles. The thaumaturgist, thoroughly skilled in occult science, can cause himself (that is, his physical body) to seem to disappear, or to apparently take on any shape that he may choose. He may make his astral form visible, or he may give it protean appearances. In both cases these results will be achieved by a mesmeric hallucination of the senses of all witnesses, simultaneously brought on. This hallucination is so perfect that the subject of it would stake his life that he saw a reality, when it is but a picture in his own mind, impressed upon his consciousness by the irresistible will of the mesmerizer.
But, while the astral form can go anywhere, penetrate any obstacle, and be seen at any distance from the physical body, the latter is dependent upon ordinary methods of transportation. It may be levitated under prescribed magnetic conditions, but not pass from one locality to another except in the usual way. Hence we discredit all stories of the aerial flight of mediums in body, for such would be miracle, and miracle we repudiate. Inert matter may be, in certain cases and under certain conditions, disintegrated, passed through walls, and recombined, but living animal organisms cannot.
Swedenborgians believe and arcane science teaches that the abandonment of the living body by the soul frequently occurs, and that we encounter every day, in every condition of life, such living corpses. Various causes, among them overpowering fright, grief, despair, a violent attack of sickness, or excessive sensuality may bring this about. The vacant carcass may be entered and inhabited by the astral form of an adept sorcerer, or an elementary (an earth-bound disembodied human soul), or, very rarely, an elemental. Of course, an adept of white magic has the same power, but unless some very exceptional and great object is to be accomplished, he will never consent to pollute himself by occupying the body of an impure person. In insanity, the patient’s astral being is either semi-paralyzed, bewildered, and subject to the influence of every passing spirit of any sort, or it has departed forever, and the body is taken possession of by some vampirish entity near its own disintegration, and clinging desperately to earth, whose sensual pleasures it may enjoy for a brief season longer by this expedient.
10th. The corner-stone of MAGIC is an intimate practical knowledge of magnetism and electricity, their qualities, correlations, and potencies. Especially necessary is a familiarity with their effects in and upon the animal kingdom and man. There are occult properties in many other minerals, equally strange with that in the lodestone, which all practitioners of magic must know, and of which so-called exact science is wholly ignorant. Plants also have like mystical properties in a most wonderful degree, and the secrets of the herbs of dreams and enchantments are only lost to European science, and useless to say, too, are unknown to it, except in a few marked instances, such as opium and hashish. Yet, the psychical effects of even these few upon the human system are regarded as evidences of a temporary mental disorder. The women of Thessaly and Epirus, the female hierophants of the rites of Sabazius, did not carry their secrets away with the downfall of their sanctuaries. They are still preserved, and those who are aware of the nature of Soma, know the properties of other plants as well.
To sum up all in a few words, MAGIC is spiritual WISDOM; nature, the material ally, pupil and servant of the magician. One common vital principle pervades all things, and this is controllable by the perfected human will. The adept can stimulate the movements of the natural forces in plants and animals in a preternatural degree. Such experiments are not obstructions of nature, but quickenings; the conditions of intenser vital actions are given.
The adept can control the sensations and alter the conditions of the physical and astral bodies of other persons not adepts; he can also govern and employ, as he chooses, the spirits of the elements. He cannot control the immortal spirit of any human being, living or dead, for all such spirits are alike sparks of the Divine Essence, and not subject to any foreign domination.
— from p. 587-590 of Isis Unveiled (Volume 2) by H. P. Blavatsky
T H E O S O P H Y 
I was drawn to this subject(theosophy) deeply when i first grabbed one booklet of the theosophical digest, until then there is a burning urge or deep longing inside me seemingly to search something that will quench the thirst, to seek knowledge and enlightenment of the visible and invisible nature of man and purpose of all created beings.
These herbs of dreams you mentioned, their psychichal effects on human systems must be dangerous otherwise one who has taken it will not be regarded as having temporary mental disorder. This temporary mental disorder can it result to the disturbance of the astral body you mentioned earlier if not checked. Again is a plant like marijuana among those plants of dreams and enchantments. If it is why are some government agencies after some people that committed no crime other than taking it.
Thank you very much for your comment.
As Madame Blavatsky says in the excerpt above: “Plants also have like mystical properties in a most wonderful degree, and the secrets of the herbs of dreams and enchantments are only lost to European science, and useless to say, too, are unknown to it, except in a few marked instances, such as opium and hashish.”
Although she says that plants have hidden or mystical properties and mentions “herbs of dreams and enchantments,” she doesn’t say that all of these without exception are good or beneficent. Some are good and beneficial; some are bad and harmful.
You’re right in saying that opium and hashish, which she mentions there, are dangerous. She specifically says this in her later book “The Key to Theosophy.”
It’s only in more recent times that the taking of “recreational drugs” and hallucinogens has become more popular. So there’s no mention of the modern craze for Marijuana in Theosophical literature. But Theosophy is in general opposed to such things.
Marijuana could indeed be described as “a herb of dreams and enchantments” but not in a good sense. Like all the similar drugs and hallucinogens, it can potentially cause great psychic and mental damage, resulting in various problems and difficulties for the soul now and later.
I hope this may answer your questions to some degree!