by Venerable K. Sri Dhammananda Maha Thera
from Ven.'s book 'What Buddhists Believe'
Vinaya is the disciplinary code for self training laid down by the Buddha for monks and nuns to observe. Vinaya plays a pivotal role in their monastic way of life.
The Buddha did not formulate the code of discipline in a single exercise. However, He instituted certain rules as and when the need arose. Vinaya Pitaka and its commentary contain many significant stories about how and why certain rules were laid down by the Buddha. According to the Buddha the best form of Vinaya was to discipline the mind, words and action. The early disciples of the Buddha were highly developed spiritually and they had little need for a set of rules to be imposed upon them. However, as the monastic order (the Sangha) grew in numbers, it attracted many others, some of whom were not so highly developed spiritually. There arose some problems regarding their conduct and way of life such as taking part in lay activities for their livelihood and yielding to temptation for sense pleasure. Owing to this situation, the Buddha had to lay down guidelines for the monks and nuns to follow so that they could distinguish the difference between the life of monks and laymen. The holy order of the monks and the nuns was a well-established religious order when compared with other existing acetic practices at that time.