Meditation is like a single log of wood. Insight and investigation are one end of the log; calm and concentration are the other end. If you lift up the whole log, both sides come up at once. Which is concentration and which is insight? Just this mind.
The influence exercised over the human mind by apt analogies is and has always been immense. Whether they translate an established truth into simple language or whether they adventurously aspire to reveal the unknown, they are among the most formidable weapons of the rhetorician.
Man, like the universe, is a machine. Nothing enters our minds or determines our actions which is not directly or indirectly a response to stimuli beating upon our sense organs from without.
But that from us aught should ascend to Heav'n So prevalent as to concern the mind Of God, high-bless'd, or to incline His will, Hard to belief may seem; yet this will prayer.
I do not perceive even one other thing, O monks, that when undeveloped and uncultivated entails such great suffering as the mind. The mind when undeveloped and uncultivated entails great suffering.