Literally, "the path of the Elders. " Of the three major branches of Buddhism, this was the earliest to crystallize into form. In contrast to Mahayana and Vajrayana, Theravada emphasizes the individual over the group, holding that it is the individual who must reach nirvana on their own. Its central virtue is thus wisdom, which is to be achieved by the arhat who attains enlightenment in this life and nirvana upon death. It discourages speculation about the nature of the cosmos, enlightenment, and nirvana, instead focusing on meditation to achieve enlightenment. The main social group is therefore the sangha, the gathered monks and nuns who support and teach each other as each one strives to achieve enlightenment.