Reply to P.B. by Buddhist priest in Ceylon--Meditation according to Buddhism is of two kinds: (a) concentration and (b) insight. The mind is first purified and the hindrances of passions, sense desires, hatred, sloth and torpor, restlessness, broodiness, and doubt are temporarily inhibited. With this concentrated mind he looks deep into the nature of the world and ego. His concentrated mind is likened to a polished mirror in which everything is reflected without distortion. Whilst in his meditation he strives to comprehend things in their true perspective as they truly are, and the truths are revealed to him whilst he is so engaged. This is why it is said that the best truths are those that are intuited by oneself, that is, intuitive truth. The Buddha gained his enlightenment by this kind of meditation.
-- Notebooks Category 4: Elementary Meditation > Chapter 1: Preparatory > # 210