nice thread....moss In my limited experience although tibetan monks are 'robust' this in no way makes it more difficult to enter 'trance' i have studied with tibetan mystics 'ngagpa' tradition of nyingma and allso the 'forest ' theravada tradition there are specific forms of trance (altered conciousness) that are enabled by many different physical psychological and pharmocological (to name but a few) that is not forgetting that non of these act independently of each other ( e.g the change in brain chemistry, when one is in deep meditation etc) then of course we have the problem of which came first the chicken or the egg? conciousness change or chemical change(which precipitateswhich) cheers muddy