Asceticism is the effort to cleanse the soul of everything that can hinder the action of God in it

"Asceticism is the effort put forth by the soul, under the action of grace, to overcome the unruly tendencies of human nature, to cleanse the soul of everything that can hinder the action of God in it, and to strive for union with God. Carmelite asceticism is definitely oriented towards contemplation. This is logical, since contemplation is the objective of Carmelite life. Carmelite asceticism has yet another characteristic: its center is love. There is nothing astonishing in this: love is the principal element of Carmelite spirituality; it is not merely its final goal, it is already there at its beginning and it is upon love that the soul relies all during its journey. Carmelite prayer is oriented towards contemplation, and while it does not undervalue reasoning, it 'consists much more in loving than in thinking.'

The efforts which the Carmelite will make to conquer his passions, his evil tendencies, and his defects, will therefore consist rather in acts of love for God than in a direct struggle against these unruly inclinations. At least this is the way recommended by St John of the Cross. He does not underestimate the efficacy of a direct struggle consisting in reflections on the ugliness and the malice of sin and the consequences it entails; or in acts of the virtue opposed to the defect of the temptation to be overcome. Instead, the manner of behavior recommended by him is to turn away from the temptation and to turn towards God and cling to Him by love. He considers this method easier, more fruitful, more perfect. In fact, not only does it free the soul from the attraction and attachment of created things, it raises the soul up to God and makes it grow in love."

-- The Spirit and Prayer of Carmel by Fr François Jamart, ocd