Getting back to Alex's initial post about "rise & fall" and whether discursive thinking is used. The way I understand things is that jhana as taught in the suttas is actually developed through insight/understanding of one or more aspects of the Buddha's Dhamma. From within jhana the rise & fall of events is clearly discerned. This type of jhana is specific to the Buddha's dispensation as it has right view as one of its causes.
An example of discursive thinking leading to penetration is here.....................
"Monks, there is a four-phrased statement that, when it is recited, a wise man will in no long time learn the meaning through discernment. I will recite it, and you learn it from me.".............................................
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'The Blessed One is the Teacher, I am a disciple. He is the one who knows, not I.' For a disciple who has conviction in the Teacher's message & lives to penetrate it, the Teacher's message is healing & nourishing.'
http://www.accesstoinsight.org/tipitaka/mn/mn.070.than.htmlSuch an approach as above obviously requires a degree of familiarisation with and acceptance of the Buddha's teachings and building upon that the Buddha's fourfold statement when contemplated would/could give rise to great joy/delight/gladness the building blocks of Buddhist meditation.
The suttas are littered with such instructions, with no recourse to actual techniques.