All three paths are available to any seeker, chosen based on inclination, aptitude and personal preference, and typically elements of all three to varying degrees are practiced by many Hindus. Classical yoga emphasizes the practice of dhyana (meditation), and this is a part of all three classical paths in Hinduism, including jñāna yoga. The path of knowledge is intended for those who prefer philosophical reflection and it requires study and meditation. Jnana yoga encourages its adepts to think and speak of themselves in the third person as a way to distance themselves from the Ego and detach their eternal self (atman) from the body related one (maya). Upanishads In the Upanishads, 'jnana yoga aims at the realization of the oneness of the individual self (Atman) and the ultimate Self (Brahman). These teachings are found in the early Upanishads. According to Chambliss, the mystical teachings within these Upanishads discuss "the way of knowledge of the Self", a union, the realization that the Self (Atman) and the Brahman are logical. The teachings in the Upanishads have been interpreted in a number of ways, ranging from non-theistic monism to theistic dualism. In former, rituals are not necessary and a path of introspection and meditation is emphasized for the correct knowledge (jnana) of self. In latter, it is the full and correct knowledge of a Vishnu avatar or Shiva or Shakti (Goddess) that is emphasized. In all its various interpretations, the paths are not necessarily mutually exclusive. A Jnana yogi may also practice Karma yoga or Bhakti yoga or both, and differing levels of emphasis. According to Robert Roeser, the precepts of Jnana yoga in Hinduism were likely systematized by about 500 BCE, earlier than Karma yoga and Bhakti yoga. Bhagavad Gita In the Bhagavad Gita, jnana yoga is also referred to as buddhi yoga and its goal is self-realization. The text considers jnana marga as the most difficult, slow, confusing for those who prefer it because it deals with "formless reality", the avyakta. It is the path that intellectually oriented people tend to prefer. The chapter 4 of the Bhagavad Gita is dedicated to the general exposition of jnana yoga, while chapters 7 and 16 discuss its theological and axiological aspects. Krishna says that jñāna is the purest, and a discovery of one's Atman: Traditions The Advaita philosopher Adi Shankara gave primary importance to jñāna yoga for the "knowledge of the absolute" (Brahman),