  In his first public discourse, known as the Turning of the Wheel  of Dharma (Pāli Dhammacakkappavattana Sutta, SN  56, 11), Siddhartha Gautama, the historical Buddha, lays out what is  considered to be the foundation of Buddhist doctrine and practice:  the middle path approach to understanding the nature of phenomena. At the level of affect the middle path steers clear of the extremes of  indulgence and austerity, while at the mental level it avoids the  extreme metaphysical positions of eternalism and annihilationism.  Thus, the middle path “leads to insight and wisdom, produces  calm, knowledge, enlightenment, and  nirvāṇa” (Saṃyutta  Nikāya, V, 420). Following his exposition of the middle  path, the Buddha proceeds to outline the four noble truths and the  eightfold noble path, which together represent the most basic aspects of Buddhist teachings. The middle path, thus, is intended both as an  ethical method and as a primer for correct reasoning. In this second  sense, the middle path relies on a particular understanding the  nature of reality as being marked by, or displaying, three specific  characteristics (tri-lakṣaṇa):  unsatisfactoriness (duḥkha), impermanence  (anitya), and the lack of an abiding self  (anātman). 