In an accordance with the hierarchy spiritus, anima, corpus (spirit, soul, body), we distinguish three types of ascesis, three types of self-control: ascesis of spirit, ascesis of soul, ascesis of body. Spiritual ascesis or mental ascesis is an ascesis of thoughts, a mental self-control. Ascesis of a soul represents control over a character.  Bodily ascesis means control of an action, conduct and behaviour.
A key to successful practice of an ascesis is to practice in an accordance with the given hierarchy: Every impulse attacks first one’s mind in form of a thought. A bad thought leads to a character disharmony, e.g., desire. Yet the desire causes wrong acting (and not the other way). This is why the beginning of every successful ascesis is to suppress a wrong thought, a bad mental impulse. 
In order to suppress incoming thoughts, much advice is given by saints and holy teachers: do not believe your thoughts, ignore them, do not pay them attention etc. In this manner one purifies his mind and as a by-effect deepens his consciousness.
If one does not respect the hierarchy and lets into their mind all kinds of forms, shapes, images and thoughts, and yet subsequently tries to fight them and resist, they become nothing more than overlaid, overshadowed or displaced into one’s unconsciousness, which leads to a dangerous polarity that will sooner or later burst out again from within.  If one is not aware of this and engages himself in a never-ending fight with the constant inflow of shapes, images and temptations, one only weakens and exhausts himself. A loss is thus only a question of time.
To stop identifying with thoughts and to annihilate all the wrong thoughts immediately in the very beginning is the key to every ascetic and thus to a victory in the greatest holy war, where the reward is the awakening and approaching to the centre of the world, which is a residence to the great peace.
 Some authors not arbitrarily call the soul the emotional body or astral body (aster = star).
 This is why there is no difference between a sinful thought, a desire for a sin, and a sinful act. Men are constantly creating their Destiny through the quality and power of their thoughts: great desire causes great obstacles to arise. Purify your mind, thus straighten your path.
 This affects mostly the beginners who cannot yet see the crucial difference between darkness and emptiness.
 Al-Jihad al-akbar from an Islamic hadith means literally the greatest holy war. This is also one of the outer meanings of Jesus’ walking on water: the immediate domination over the world of shapes and forms. This superiority is an implicit condition to every initiation. See also Ephesians 6:11-19.