lightendlesslight.org

...
An integral knowledge demands an exploration, an unveiling of all the possible domains of consciousness and experience. For there are subjective domains of our being which lie behind the obvious surface; these have to be fathomed and whatever is ascertained must be admitted within the scope of the total reality. An inner range of spiritual experience is one very great domain of human consciousness; it has to be entered into up to its deepest depths and its vastest reaches. The supraphysical is as real as the physical; to know it is part of a complete knowledge. The knowledge of the supraphysical has been associated with mysticism and occultism, and occultism has been banned as a superstition and a fantastic error. But the occult is a part of existence; a true occultism means no more than a research into supraphysical realities and an unveiling of the hidden laws of being and Nature, of all that is not obvious on the surface. It attempts the discovery of the secret laws of mind and mental energy, the secret laws of life and life-energy, the secret laws of the subtle-physical and its energies,—all that Nature has not put into visible operation on the surface; it pursues also the application of these hidden truths and powers of Nature so as to extend the mastery of the human spirit beyond the ordinary operations of mind, the ordinary operations of life, the ordinary operations of our physical existence. In the spiritual domain which is occult to the surface mind in so far as it passes beyond normal and enters into supernormal experience, there is possible not only the discovery of the self and spirit, but the discovery of the uplifting, informing and guiding light of spiritual consciousness and the power of the spirit, the spiritual way of knowledge, the spiritual way of action. To know these things and to bring their truths and forces into the life of humanity is a necessary part of its evolution. Science itself is in its own way an occultism; for it brings to light the formulas which Nature has hidden and it uses its knowledge to set free operations of her energies which she has not included in her ordinary operations and to organise and place at the service of man her occult powers and processes, a vast system of physical magic,—for there is and can be no other magic than the utilisation of secret truths of being, secret powers and processes of Nature. It may even be found that a supraphysical knowledge is necessary for the completion of physical knowledge, because the processes of physical Nature have behind them a supraphysical factor, a power and action mental, vital or spiritual which is not tangible to any outer means of knowledge.
...

Veda and Vedanta are one side of the One Truth; Tantra with its emphasis on Shakti is another; in this yoga all sides of the Truth are taken up, not in the systematic forms given them formerly but in their essence, and carried to the fullest and highest significance. But Vedanta deals more with the principles and essentials of the divine knowledge and therefore much of its spiritual knowledge and experience has been taken bodily into the Arya. Tantra deals more with forms and processes and organised powers—all these could not be taken as they were, for the integral yoga needs to develop its own forms and processes; but the ascent of the consciousness through the centres and other Tantric knowledge are there behind the process of transformation to which so much importance is given by me—also the truth that nothing can be done except through the force of the Mother.

The process of the Kundalini awakened rising through the centres as also the purification of the centres is a Tantric knowledge. In our yoga there is no willed process of the purification and opening of the centres, no raising up of the Kundalini by a set process either. Another method is used, but still there is the ascent of the consciousness from and through the different levels to join the higher consciousness above; there is the opening of the centres and of the planes (mental, vital, physical) which these centres command; there is also the descent which is the main key of the spiritual transformation. Therefore, there is, I have said, a Tantric knowledge behind the process of transformation in this yoga.

In our yoga there is no willed opening of the chakras, they open of themselves by the descent of the Force. In the Tantric discipline they open from down upwards, the Muladhar first; in our yoga, they open from up downward. But the ascent of the force from the Muladhar does take place.

In the Tantra the centres are opened and Kundalini is awakened by a special process, its action of ascent is felt through the spine. Here it is a pressure of the Force from above that awakens it and opens the centres. There is an ascension of the consciousness going up till it joins the higher consciousness above. This repeats itself (sometimes a descent also is felt) until all the centres are open and the consciousness rises above the body. At a later stage it remains above and widens out into the cosmic consciousness and the universal self. This is a usual course, but sometimes the process is more rapid and there is a sudden and definite opening above.

The ascension and descent of the Force in this yoga accomplishes itself in its own way without any necessary reproduction of the details laid down in the Tantric books. Many become conscious of the centres, but others simply feel the ascent or descent in a general way or from level to level rather than from centre to centre, that is, they feel the Force descending first to the head, then to the heart, then to the navel and still below. It is not at all necessary to become aware of the deities in the centres according to the Tantric description, but some feel the Mother in the different centres. In these things our sadhana does not cleave to the knowledge given in the books, but only keeps to the central truth behind and realises it independently without any subjection to the old forms and symbols. The centres themselves have a different interpretation here from that given in the books of the Tantriks.

Yes, the object of our yoga is to establish direct contact with the Divine above and bring down the divine Consciousness from above into all the centres. Occult powers belonging to the mental, vital and subtle physical planes are not our object. One can have contact with various Divine Forces and Personalities on the way, but there is no need to establish them in the centres, though sometimes that happens automatically (as with the four Personalities of the Mother) for a time in the course of the sadhana. But it is not a rule to do so. Our yoga is meant to be plastic and to allow all necessary workings of the Divine Power according to the nature, but these in their details may vary with each individual.

Occultism is the knowledge and right use of the hidden forces of Nature.
Occult forces are the forces that can only be known by going behind the veil of apparent phenomena—especially the forces of the subtle physical and supraphysical planes.

An activity of the astral plane in contact with the astral forces attended by a leaving of the body is not a spiritual aim but belongs to the province of occultism. It is not a part of the aim of yoga. Also fasting is not permissible in the Ashram, as its practice is more often harmful than helpful to the spiritual endeavour.

This aim suggested to you seems to be part of a seeking for occult powers; such a seeking is looked on with disfavour for the most part by spiritual teachers in India, because it belongs to the inferior planes and usually pushes the seeker on a path which may lead him very far from the Divine. Especially, a contact with the forces and beings of the astral (or, as we term it, the vital) plane is attended with great dangers. The beings of this plane are often hostile to the true aim of spiritual life and establish contact with the seeker and offer him powers and occult experiences only in order that they may lead him away from the spiritual path or else that they may establish their own control over him or take possession of him for their own purpose. Often representing themselves as divine powers, they mislead, give erring suggestions and impulsions and pervert the inner life. Many are those who, attracted by these powers and beings of the vital plane, have ended in a definitive spiritual fall or in mental and physical perversion and disorder. One comes inevitably into contact with the vital plane and enters into it in the expansion of consciousness which results from an inner opening, but one ought never to put oneself into the hands of these beings and forces or allow oneself to be led by their suggestions and impulsions. This is one of the chief dangers of the spiritual life and to be on one's guard against it is a necessity for the seeker if he wishes to arrive at his goal. It is true that many supraphysical or supernormal powers come with the expansion of the consciousness in yoga; to rise out of the body consciousness, to act by subtle means on the supraphysical planes, etc. are natural activities for the yogi. But these powers are not sought after, they come naturally, and they have not the astral character. Also, they have to be used on purely spiritual lines, that is by the Divine Will and the Divine Force, as an instrument, but never as an instrumentation of the forces and beings of the vital plane. To seek their aid for such powers is a great error.

Prolonged fasting may lead to an excitation of the nervous being which often brings vivid imaginations and hallucinations that are taken for true experiences; such fasting is frequently suggested by the vital Entities, because it puts the consciousness into an unbalanced state which favours their designs. It is therefore discouraged here. The rule to be followed is that laid down by the Gita which says that “Yoga is not for one who eats too much or who does not eat”—a moderate use of food sufficient for the maintenance of health and strength of the body.
...

As regards secrecy, a certain discretion or silence about the instructions of the Guru and one's own experiences is always advisable, but an absolute secrecy or making a mystery of these things is not. Once a Guru is chosen, nothing must be concealed from him. The suggestion of absolute secrecy is often a trick of the astral powers to prevent the seeking for enlightenment and succour.

By black magic is meant the occultism of the adverse powers—the occultism of the divine Powers is quite different. One is based on unity, the other on division.