the All Ceylon Buddhist Congress, the Sarvodaya Shramadana of A. T. Ariyaratne, the NGO's founded by Sulak Sivaraksa such as Santi Pracha. Monastic vocation Theravāda sources dating back to medieval Sri Lanka (2nd century BCE to 10th century CE) such as the Mahavamsa show that monastic roles in the tradition were often seen as being in a polarity between urban monks (Sinhala: , Pāli: gāmavasī) on one end and rural forest monks (Sinhala: , Pali: araññavasi, nagaravasi, also known as Tapassin) on the other. The ascetic focused monks were known by the names Pamsukulikas (rag robe wearers) and Araññikas (forest dwellers). The Mahavamsa mentions forest monks associated with the Mahavihara. The Pāli Dhammapada Commentary mentions another split based on the "duty of study" and the "duty of contemplation". This second division has traditionally been seen as corresponding with the city – forest split, with the city monks focusing on the vocation of books (ganthadhura) or learning (pariyatti) while the forest monks leaning more towards meditation (vipassanadhura) and practice (patipatti). However this opposition is not consistent, and urban monasteries have often promoted meditation while forest communities have also produced excellent scholars, such as the Island Hermitage of Nyanatiloka. Scholar monks generally undertake the path of studying and preserving Theravāda's Pāli literature. Forest monks tend to be the minority among Theravāda sanghas and also tend to focus on asceticism (dhutanga) and meditative praxis. They view themselves as living closer to the ideal set forth by the Buddha, and are often perceived as such by lay folk, while at the same time often being on the margins of the Buddhist establishment and on the periphery of the social order. While this divide seems to have been in existence for some time in the Theravāda school, only in the 10th century is a specifically forest monk monastery, mentioned as existing near Anuradhapura, called "Tapavana". This division was then carried over into the rest of Southeast Asia as Theravāda spread. Today there are forest based traditions in most Theravāda countries, including the Sri Lankan Forest Tradition, the Thai Forest Tradition as well as lesser known forest based traditions in Burma and Laos, such as the Burmese forest based monasteries (taw"yar) of the Pa Auk Sayadaw. In Thailand, forest monks are known as phra thudong (ascetic wandering monks) or phra thudong kammathan (wandering ascetic meditator). Ordination The minimum age for ordaining as a Buddhist monk is