When the object of thought of meditation merge with self conscious of soul in  control mind  ,  control mind   itself disappear in  natural  essence and this state of stilled body posture, breath, organs of action and thought process consciously is called spiritual union with self conscious of soul in  control mind   (Samadhi). When the purpose of subject of meditation is absorbed in  control mind  , "I" or self-ego or  simple mind  disappears. This is spiritual union. When the object of insight vision  flow merges with thought of meditation of the subject of self-conscious, the union of subject and object becomes spiritual union. When the object of meditation glows without the intervention of self-conscious, meditation flow in  control mind   is called to spiritual union.

It is when the  control mind   becomes absorbed in the form of the object meditated upon or in the idea embodied in the form and becomes unaware of its separateness and also becomes unaware of the personal self-being ness. It is then that communion or spiritual union ensues. When the form of the object meditated upon appears the same and gets bereft of its own character, it is then that communion or spiritual union results. When the field of observation and the observing intelligence merge as if their own form is abolished and the total intelligence shines as the one true essence reality, it is then that there appears self conscious of soul in true form that results in communion or spiritual union. Communion or spiritual union is the 8^th limb of the perfect discipline of preparatory yoga.

When meditation in the thought of an object or subject becomes aware only of the thought of mediation and when the very form of the object or subject gets eliminated and insight vision  does not think of any thought and meditation does not entertain any thought and no thought intrudes upon insight vision  and meditation, it is then that communion or spiritual union gets ushered in. When the experience of meditation and insight vision  becomes pure self-conscious in  control mind  , it is then that the state of communion or spiritual union ensues.

The Great Sage Patanjali says that when thought during insight vision  and meditation about a subject or object remains only for namesake and insight vision  and meditation are not able to think of anything else and are totally absorbed in the subject or object or the thought of the subject or object, such an experience results in communion or spiritual union. When meditation becomes continuous and constant, the self-conscious also becomes the object of the meditation itself. This state is called the state of communion or spiritual union. Communion or spiritual union is the perfect insight vision  and meditation that results in super self-conscious experience in  control mind  .

At the time of cultivation and disciplining of the preparatory perfect discipline of withdrawal of senses, the waves of cravings keep on undulating in different and innumerable cells of the  simple mind  in the shape of thought  about a subject or object or place of matter world. These waves of cravings are to be stopped consciously and through constant practice in  control mind  .

At the time of cultivation and disciplining of meditation, meditation is to be connected through one cell of thought of the  control mind  . The connection is to be made with that cell of the  control mind  , which harbors the desire of the  control mind   for a particular subject or objector place itself. The practice of keeping the remaining cells of the  control mind   and their subjects and objects and places consciously disconnected from the  control mind   is to be cultivated and disciplined. In the cultivation and disciplining of the perfect discipline of meditation, the practice of consciously keeping the meditation disconnected from the  control mind   is to be cultivated and disciplined. In the cultivation and disciplining of the perfect discipline of meditation the connection of meditation with one cell of the  control mind   is to be consciously contemplated. Meditation is to be connected in the depth of thought  with that one connected cell of the  control mind  .

At the time of cultivation and disciplining of the preparatory discipline of meditation, meditation is to be connected with one cell of the  control mind  . The connection of the mind thought  with that cell is to be tied by descending into the depth of the  control mind  . The descent into the depth of the conscious should be to such a degree that the  control mind   cell thinks only about the subject matter of the thought and does not think of anything else. The result is that nothing gets thought. The result is that no spiritual knowledge is felt and experienced about the meaning and form of the subject matter. When meditation descends into a single thought of  control mind   and establishes its connection with one cell of the conscious and establishes its connection with the subject matter of meditation and gets a feel about the subject matter and manifests the subject matter as if in sleep, there ensues a state of meditation that is called communion or spiritual union. It is also called seeded communion or spiritual union. This is the 8^th limb of the preparatory perfect discipline. The Great Sage Guru says that the formless cells of the  control mind   and the thought  and cravings contained in the  simple mind  and lack of spiritual knowledge contained in the cravings and all these lie hidden in lack of spiritual knowledge. Spiritual knowledge about the soul is far beyond it. Before acquiring that spiritual knowledge, consciousness mind is to be taken out of the grip of lack of spiritual knowledge.

Pure self conscious of the spiritual knowledge about lack of spiritual knowledge is to be acquired during the state of seeded communion or spiritual union. This spiritual knowledge directly comes in contact with soul’s self conscious after crossing beyond the  control mind  . Spiritual knowledge about  control mind   that is directory of  natural  essence is as pure as is spiritual knowledge about the soul essence. When  control mind   attains spiritual knowledge of the lack of spiritual knowledge of mind, it is then that meditation through  control mind   becomes capable of apprehending the spiritual knowledge of the soul. Conscious mind spiritual knowledge is, however, attained through the cultivation and disciplining of seeded communion or spiritual union. Spiritual knowledge of soul gets attained through the cultivation and disciplining of seedless communion or spiritual union. It means that such a spiritual knowledge gets attained when meditation by getting spiritual knowledge about  control mind   becomes craving free. It starts attaining this spiritual knowledge when meditation attains spiritual knowledge about true natural’s  natural  essence state, wherein natural’s attributes namely luminous and melodious, motion and action and slothful and its cosmic laws stop performing their functions. When the  control mind   becomes craving free from Natural’s very  natural  state and becomes totally free from its  natural  elements subjects and matter elements subjects and endless matter forms of endless universe, it is then that it starts comprehending spiritual knowledge of the soul.

The Great Sage says that the soul, consciousness and fourth true essence state of natural have no form. They do not have even a formless shape. Whatever  natural  form is there is without shape. As such, when meditation on reaching that state of spiritual union tries to consciously imagine a shape, it results in imaginative conjecture only. No solid experience gets felt. Thinking does not get into the grasp of insight vision  and meditation. Whatever gets into the grasp is only a pure consciousness of the true spiritual knowledge that is the spiritual knowledge of true natural, soul and God essence. True spiritual knowledge of natural, soul and God essence is only one. This is because all these three are in reality one true essence. They are the three states of the flow of true cosmic energy into one essence or reality.

The Great Sage says that wealth, offspring, body, senses, the formless mind, thought  of  simple mind , cravings of thought , longings, attachments and affections, aversions and fear, distress in the mind and search for happiness with the help of mind’s intellect-all these are subjects matter of Natural. All these are the creation of Natural’s attributes namely luminous and melodious, motion and action and slothful and their cosmic laws. The creation of these aspects is, however, different from the self-conscious of the life form. The real existence of a life form is the soul that is wrapped over and around god. The soul has innumerable self-conscious of life form through which it receives cosmic energy from interior God essence. This energy flows in Natural so long as a soul’s innumerable self-conscious of life form are in the grip of natural. The flow of God’s cosmic energy that takes place through inhalation and exhalation stops in those self-conscious of life form flow which are not in the grip of natural. A person, who acquires this spiritual knowledge, becomes spiritual knowledgeable and his learning makes him immortal. A single essence has created all the life form self-conscious of a single soul. Natural has created a single interior core of  control mind   of all the life form. It has created  control mind   cells for the individual life form. It has created individual lingering past subliminal impressions for all the life form.

Meditation and insight vision  that is in  control mind  , is to be cultivated and disciplined up to the interior core of  control mind   during seeded communion or spiritual union. The interior core of  control mind   is rooted in the deepest self conscious of all the life form. On reaching there, nothing, however, gets experienced, felt or observed. Whatever gets experienced is merely a feeling of self-conscious being in the grip of  natural  essence,  natural  and matter elements and endless forms there of in universe.