Jamgon Kongtrul (1813-1899) defines Yoga tantra by making reference to the Two Truths doctrine and 'method' (Sanskrit: upaya) and 'wisdom' (Sanskrit: prajna) and is rendered into English from the Tibetan by Guarisco and McLeod, et.al. (2005: p.128) thus: "Yoga tantra is so named because it emphasizes the inner yoga meditation of method and wisdom; or alternatively, because based on knowledge and understanding of all aspects of the profound ultimate truth and the vast relative truth, it emphasizes contemplation that inseparably unites these two truths."