[Parentheses are from the original. Bracketed terms are added.]
Mind, through ignorance and indiscrimination, considers its false personality to be true and thinks it is the doer of all Karmas and thus becomes egoistic. It imagines that it is in bondage. It identifies itself with the Jivatman [the individual soul]; it becomes Jivatman itself and takes the responsibility upon itself for doing good or bad Karmas and enjoying or suffering from their fruits. Hence is mind the doer of Karmas (actions) and responsibility for the Karmas, therefore, rests with it.
Mind is the stealer of Atman [eternal consciousness]. It is a thief. Mind drags the Jivatman into Vishayas (sensual enjoyments). Jivatman is the Abhasa of Chaitanya, or reflected intelligence in mind. Mind and Jivatman always live together. They cannot be separated. Slay the mind, the stealer of Atman, through Vichara, [1, 2] Manana [contemplation] and Nididhyasana (constant and profound meditation) on Brahman.
[1. Discernment. en.wikipedia.org/
Mind has the potency of creating or undoing the whole world in the twinkling of an eye. Therefore, slay this mind, the slayer of Atman, whether through the destruction of Vasanas (latent subtle desires) or the control of Prana or Brahma-Vichara and Mahavakya-Chintana [reflection on the great sayings of the Upanishad]. 
The best means of disposing of this great danger of Maya involving all in pains, is the destruction of mind. With the destruction of the mind, all the three periods of time vanish into nothing. With the destruction of mind, Atman begins to dawn.
The extinction of Vasanas (Vasana-Kshaya), Manonasa (annihilation of the mind) and Tattva-Jnana (understanding of the Reality), when practised together for a long time are regarded as fruitful. They should be practised at a time [all at once]. So long as these three are not equally practised again and again, the Supreme Seat (Parama Pada)  cannot be attained even after a lapse of hundreds of years. Through the practice of these three for a long time, the firm knots of the heart are cut without doubt, like the breaking of the threads in a lotus-stalk rent in twain.
[4. Final beatitude, position, liberation. Also, Incorruptable light. en.wikipedia.org/wiki/
The Meaning of Manonasa
Destruction of the mind does not mean annihilation of the Self. The Vedantins divide the mind into the higher and the lower, of which the lower one leading to desires is asked to be destroyed.
Destruction of desires, annihilation of Ahankara,  destruction of Sankalpa  all mean control of mind or annihilation of mind (Manonasa or Amanaskata). Destruction of egoism, Raga-Dvesha (attraction and repulsion for objects) and all Vasanas alone is Manonasa. Manonasa comes through the destruction of the Vasanas. Manonasa does not mean that you should take a sword and cut the mind to pieces.
[5. Ego-sense. en.wikipedia.org/wiki/
[6. Mental conceptions. en.wikipedia.org/wiki/
Manonasa means the death of the present form of the mind (i.e., the instinctive mind of emotions and passions), the form which perceives differences where none exists, which identifies the Self with the body. Its death really means its transformation into and, therefore, the birth of cosmic consciousness.
Vast majority of persons live in Annamaya Kosha ["foodstuff" body or sheath] only. [7a, 7b] Their thoughts are directed towards eating, cleansing the body and putting on neat dress. That is all. Even the so-called educated persons live in Annamaya Kosha only. Sometimes, they live in Manomaya Kosha (mental sheath).
[7a. The five sheaths: en.wikipedia.org/
[7b. Nisargdatta: The food-body enables the senses to function. realization.org: quintessence of Nisargadatta ]
A spiritual aspirant and a Vivekin live in Vijnanamaya Kosha (Buddhi sheath). The Vijnanamaya Kosha is developed by abstract thinking and reasoning, by systematic meditation, Brahma-Chintana [thinking and reflecting on the Absolute], study of the Upanishads, the Yogavasishtha and the Brahma-Sutras. You must all develop the Vijnanamaya Kosha by the study of Vedantic literature and pure thinking. Then you are safe. Mind will stop to deceive and torment you.
Laya-Chintana [absorbtion] of Antahkarana [mind levels] [8a]
Mind is absorbed in Mahat or Buddhi. Individual Buddhi is absorbed in the Cosmic Buddhi; Cosmic Buddhi in Avyakta; [8b] Avyakta in Brahman. This is the Laya-Chintana of Antahkarana or Mind.
[8a. Antahkarana is the totality of the levels of the mind, as variously defined. The buddhi and the manas. Literally defined as "the inner cause."en.wikipedia.org/
[8b. Unmanifested mind. en.wikipedia.org/wiki/
Sambhavi Mudra, Bhrukuti-Drishti (looking at the spot midway between the two eyebrows), Nasikagra-Drishti (looking steadily at the tip of the nose), Nadanusandhana (hearing the sounds of the ear) – all belong to Laya-Yoga [kundalini yoga]. By these practices the mind gets Laya soon. The Unmani state [state of thoughtlessness or no-mind] supervenes rapidly. The Unmani Avastha [state] of Laya-Yogis corresponds to the Bhava-Samadhi of Bhaktas.  In Sambhavi Mudra, the eyes are open but the mind is fixed on the Lakshya [inner focal point]. The eyes do not see the external objects.
When the mind and senses are thinned out and eventually controlled, Karanendriya-Vyapara (the various activities of Antahkarana and senses) ceases. Jivatva (personality-notion and sensation) vanishes. Brahmatva (existence) remains. This is Kevala Asti. 
[10. Mind is controlled, sense activities and personality cease.]
The Two Kinds of Manonasa
[Svarupa means "with form." Arupa means "without form."]
Manonasa is of two kinds, viz., (i) Svarupa Manonasa, destruction of the Svarupa of mind, as in the case of the Jivanmukta and (ii) Arupa Manonasa, destruction of the very form of the mind, as in the case of Videhamuktas, when they leave off their physical bodies. The first is termed "destruction of the mind with form [svarupa]." The second is termed "destruction of the mind without form [arupa]."
How To Bring About Manonasa
There are five ways of effecting Manahkshaya (destruction of the mind). Two are Yogic methods. Three ways concern Jnana Yoga. 
[10. Path of inner knowledge, path of self-realization. en.wikipedia.org/
- (i) When a thought arises, drive it out. Say unto yourself, "Neti, Neti – not this thought, not this thought. I do not want this thought."
- (ii) Pratipaksha Bhavana – substitute a counter-idea, love for hatred, courage for fear, etc.
- (iii) Have Brahma-Bhavana. All Sankalpas will die.
- (iv) Be a Sakshi of the mind. Be indifferent (Udasina).
- (v) Make the enquiry, "Who am I?" constantly. All thoughts will die. For a man of Vichara (enquiry), the mind dwindles into an airy nothing. This is easier and more effective than the "Neti, Neti" or "Pratipaksha Bhavana" method.
Sankalpa [mental conception], desire, Raga [attachment], Dvesha [aversion], Ahankara [ego sense] and mind are the six bricks of the mansion of Jiva. They are the six links of the chain which constitutes the personality-Jiva. Destruction of one brick or one link brings about the destruction of the whole edifice or whole chain.
Therefore, cut off daily the branches of Sankalpa from this dire tree of Manas [mind] and ultimately destroy the tree of mind at its root completely. The cutting off the branches is only secondary. The eradication of the tree by removal of 'I' is the primary thing. Therefore, if through virtuous actions you destroy the idea of 'I' which forms the very root of the tree of mind, then it will not spring up again.
Power, possessions, money and knowledge strengthen the Abhimana, i.e., the idea of 'I.'  They thicken the mind also. They should be given up in order to thin out the 'I' and the mind. It is through Vairagya  and Tyaga  that you will have to thin out the mind. When the mind becomes thread-like through the thinning process, it is termed Tanumanasi. 
[13. Dispassion. en.wikipedia.org/
[14. Abandonment. en.wikipedia.org/
The mind can be controlled either through the control of Prana (Hatha Yogic method) or the arrest of the fluctuation of the mind (Raja-Yogic method, the "Yogas-chittavrittinirodhah" of Maharshi Patanjali). [16, 17] Control of mind leads to stoppage of breath and control of breath leads to stoppage of mind, because Prana and mind are under one Sambandha [relationship]. During meditation, the breathing becomes very slow. Those who practise meditation may be aware of this fact. This goes to show that when the mind is concentrated, Prana stops by itself without any effort.
Pranayama (control of breath) cannot bring about Manonasa (annihilation of the mind). The Vrittis (mental disturbances) are quietened only temporarily.
Constant and pure thought of Paramatman [supreme soul]  in our heart would bring about the natural Kumbhaka  and absorption of the mind in the heart, the ultimate state and the state which the sages long for. Absorption of the mind in itself is Eternal Bliss (Salvation). Through direct perception of Atman, the mind will be destroyed and will generate infinite Bliss. In such a perception, the seer, sight and the seen become one.
[19. Pause between breaths. wikipedia.org/wiki/
Manonasa and Manolaya
Manolaya is a temporary absorption of the mind in the object of meditation. When you meditate on the form of Bhagavan Sri Krishna, the mind becomes absorbed in the form of Bhagavan Sri Krishna temporarily.
Manolaya takes place during sleep.  The mind gets involved into its cause, the Mula Avidya [root ignorance].
[20. Scroll on this page to see a chart based on Ramana Maharshi's teaching: albigen.com/
Manolaya is not sufficient for attainment of Jnana. In Manolaya, the mind is prone to revive. Manolaya cannot save you from bondage. Manolaya cannot give you Mukti.
It is only Manonasa (annihilation of the lower mind) that can give you liberation. In Manonasa, the mind revives not and is dead. Manonasa is brought about by Brahma-Jnana [contemplation on Brahman].
Further reading: Manonasa: A Spiritual Autobiography, by Michael Langford at Amazon
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