As It Is – Barry Long – About Evolution and Enlightenment : 

“… Enlightenment of course does not evolve. What evolves is the individual understanding and depth of cognitive perception. This is a process of psycho-logical negation ­ a spiritual deepening accompanying the continuous giving up of reliance on the mind’s convictions and emotional feelings. Sometimes the perception evolves to a point of ultimate spiritual realization. This state is sometimes referred to as enlightenment; but usually not by anyone who is realized…”