I'm reading Michel Foucault at the moment for my dissertation and came across the following part about mysticism in Foucault's 'Security, Territory, Population' (2007). Foucault describes mysticism as a technique of 'counter-conduct' against the kind of power which was imposed by the Catholic Church before the Reformation (Foucault calls it the 'pastorate'). I think it is worthwhile thinking about mysticism as a form of counter-conduct even today when considering what Foucault writes on it:

'(...) A third form of counter-conduct is mysticism, that is to say, the privileged status of an experience that by definition escapes pastoral power. Basically, pastoral power developed a system of truth that, as you know, went from teaching to examination of the individual; a truth conveyed as dogma to all the faithful, and a truth extracted from each of them as a secret discovered in the depths of the soul. Mysticism is a completely different system...In mysticism the soul sees itself. It sees itself in God and it sees God in itself. To that extent mysticism fundamentally, essentially, escapes examination. Second, as immediate revelation of God to the soul, mysticism also escapes the structure of teaching and the passing on of truth from someone who knows it to someone to whom it is taught...Mystical experience short-circuits this hierarchy and the slow circulation of the truths of teaching. Third, ...[mysticism] has a completely different principle of progress, since teaching follows a regular progression from ignorance to knowledge through the successive acquisition of comulative elements, whereas the mystical path passes through a play of alternations - night/day, dark/light, loss/return, absence/presence - which are continually reversed...In mysticism there is an immediate communication that may take the form of a dialogue between God an the soul, of appeal and response, of the declaration of God's love of the soul, and of the soul's love of God.'