 The monistic type, which according to Zaehner is based upon the experience of the unity of one's soul in isolation from the material and psychic world, includes early Buddhism and Hindu schools such as Samkhya and Advaita vedanta.Nature mysticism refers to "an experience of Nature in all things or of all things as being one," and includes, for instance, Zen Buddhism, Taoism, much Upanishadic thought, as well as American Transcendentalism.Within the second 'monistic' camp, Zaehner draws a clear distinction between the dualist 'isolationist' ideal of Samkhya, the historical Buddha, and various gnostic sects, and the non-dualist position of Advaita vedanta.