Burton RA. “On being certain. Believing you are right even when you’re not.” St. Martin’s Griffin, NY, 2008.
Burton's book takes one as far as the intellect can go. But the intellect hits a glass ceiling, arresting at a relatively early stage in the normal psychosocial development trajectory. Sadly, many scientifically-educated people (religiously) believe that science / cognition is the source of all reliable information, and that Freud's "ordinary unhappiness" is "as good as it gets."
If we seek the truth, and can handle it, we explore what is true with all our senses (mind-heart) open - with an "I don't know mind." This involves letting go of all ego-maintaining dualistic magical thinking. Many spiritual seekers hit and arrest at an emotional glass ceiling - unwilling to let go of comforting dogmas which they've outgrown.
Sitting meditation, particularly over years of serious continuous practice and meditation retreats, gradually helps "process" obstacles to experiencing reality. This is mind-body work that each individual needs to do for herself to experience - even the Buddha didn't offer short-cuts.
See also: http://mindfulnessforeveryone.blogspot.ca/2013/03/304-positive-psychology-cynicism.html