Meditation is the emptying of the mind completely and totally. One cannot empty the mind forcibly, according to any method, system or school. One must see the utter fallacy of any system. The pursuit of a system is the pursuit of experience, to achieve a further experience or the ultimate experience. So when one understands the nature of experience, you brush all this aside with one sweep. It is finished forever so that your mind never follows anybody, pursues no experience or visions. All visions and heightened sensitivity is self-centred activity, either through drugs, discipline, rituals, worship or prayer.