Single-mindedness and will are needed


[1 of 3] St. Teresa of Avila (1515-1582, Spain): primary subject "Contemplation" (search under Inner Life/Practices)": detail "From 'Way of Perfection'"
What does it behove a man to do to deserve and procure this birth to come to pass in him: is it better for him to do his part towards it, to imagine and think about God, or should he keep still in peace and quiet so that God can speak and act in him while he merely waits on God's operation? … The best and utmost of attainment in this life is to remain still and let God act and speak in thee. When the powers have all been withdrawn from their bodily forms and functions, then is this Word spoken. Thus he says: 'In the midst of the silence the secret word was spoken to me.' The more completely thou art able to in-draw thy faculties and to forget those things and their images which thou hast taken in, the more, that is to say, thou forgettest the creature, the nearer thou art to this and the more susceptible thou art to it.
 Here the soul is scattered abroad among her powers and dissipated in the act of each: the power of seeing is in the eye, the power of hearing in the ear, the power of tasting in the tongue, and her powers are accordingly enfeebled in their interior work, scattered forces being imperfect. It follows that for her interior work to be effective, she must call in all her powers, recollecting them out of external things to one interior act.
 "To achieve the interior act one must assemble all one's powers as it were into one corner of one's soul, where, secreted from images and forms, one is able to work. In this silence, this quiet, the Word is heard. There is no better method of approaching this Word than in silence, in quiet: we hear it and know it aright in unknowing. To one who knows naught it is clearly revealed."

[2 of 3] Inge (Dean) (1860-1954, England): primary subject "Mysticism, experiences of" (search under Inner Life/Experiences)": source "Philosophy of Plotinus: Gifford Lectures 1917-1918, vol.2"
The mystical state never occurs except as a sequel to intense mental concentration, which the majority of human beings are unable to practice except for a few minutes at a time. Our minds are continually assailed by a crowd of distracting images, which must be resolutely refused an entrance if we are to bring any difficult mental operation to a successful issue. The necessity of this concentration is insisted on by all the mystics, so that it is superfluous to give quotations. Most of them speak of producing an absolute calm in the soul, in order that God may speak to us without interruption. They often tell us that the will must be completely passive, though the stern repression of the imagination which they practice is only possible by a very exhausting effort of the will. All external impressions must be ignored; the contemplative must be impervious to sights and sounds while he is at work. In extreme cases a kind of catalepsy may be produced, from which it is not easy to recover; but this is not a danger to be apprehended by many. The mystical experience is not necessarily associated with meditation on the being and attributes of God. Any concentrated mental activity may, it seems, produce it.

[3 of 3] Vivekananda (1863-1902, India): primary subject "Morality, and ethics" (search under Inner Life/Teachings)": detail "‘Notes of Lectures’: ‘Jnana and Karma’"
Why should a man be moral and pure? Because this strengthens his will. Everything that strengthens the will by revealing the real nature is moral. Everything that does the reverse is immoral.