The journey of the soul is depicted here as a sequence of meetings with various Buddhist teachers, each meeting or stage separated by the Sea of Samsara which represents a challenge to be overcome.  The Arhat Nagasena, depicted at the lower right, is the first teacher of the somewhat reluctant student.  Nagasena (fl. 150 BC) is most noted for having answered a series of questions about Buddhism posed by Menander, an Indo-Greek king of northwestern India, resulting in his conversion. Amitayus is at the middle left.  Avalokiteshvara, at the middle right, is encouraging the student, who gazes towards Gautama at the upper left.