The earliest available teachings of the Buddha are to be found in Pali literature and belongs to the school of the Theravadins, who may be seen as the most orthodox school of Buddhism.

Countries such as Sri Lanka, Cambodia, Laos, Burma, and Thailand embraced the principles of the Theravada school and any differences there might be between the various schools from these countries is restricted to minor or exterior matters.

Theravada admits the human characteristics of the Buddha, and is characterised by a psychological understanding of human nature; this school emphasises a meditative approach to the transformation of consciousness. According to this point of view, the teaching of the Buddha is very plain. He asks us to 'abstain from all kinds of evil, to accumulate all that is good and to purify our mind'. These can be accomplished by The Three Trainings: the development of ethical conduct, meditation and insight-wisdom.

Briefly, the underlying philosophy is that all worldly phenomena are subject to three characteristics - they are impermanent and transient; they are unsatisfactory; and that there is nothing in them which can be called one's own, nothing substantial, nothing permanent.

All compounded things are made up of two elements - the non-material part and the material part. They consist of five constituent groups, namely the material quality, and the four non-material qualities - sensations, perception, mental formatives and consciousness.

The ideal of life of the followers of this school is the Arhat, a 'worthy person' who reached a perfected state of insight (Nibanna) and attained a state "no more returning" to the worldly life.