Manana (Deep Thinking / Reflection)

"By Shravana, Knowledge dawns. That is the flame. By Manana, the Knowledge is not allowed to vanish. Just as the flame is protected by a wind-screen, so the other thoughts are not allowed to overwhelm the right knowledge. By Nididhyasana, the flame is kept up to burn bright by trimming the wick. Whenever other thoughts arise, the mind is turned inward to the light of true knowledge...The inquiry “Who am I?” is the Shravana. The ascertainment of the true import of ‘I’ is the Manana. The practical application on each occasion is Nididhyasana."
                                                                                                               - Ramana Maharshi

Manana removes "Prameya-gata" doubts... For example, a "Prameyic" doubt can refer to the doubt as to whether "Jeeva" (the individual soul, that is you and me) and "Brahman" (the over soul, sometimes also addressed as God) are one and the same or not...