When the esoteric doctrines of the last phase of Indian Buddhism spread in Tibet, there emerged a progressive development of yogic practices and ideas that considered light as an essential ontological principle. In these traditions, we can observe an evolving model of visionary yoga.
Gradually a metaphysics of light took form that strongly characterized the yogic theory and praxis. Light was seen as the fundamental structural component of all the universe, both from a cosmological and ontological point of view.
In this lecture I will focus on the main traits of this metaphysics of light, as it emerges from the esoteric treatises of the Indian Buddhist Kālacakratantra, and of the Tibetan heterodox treatises of the Rnying ma rgyud ‘bum and of the Zhang zhung snyan rgyud.