But we are now considering not these Mahâ-purushas, the great Incarnations, but only the Siddha-Gurus (teachers who have attained the goal); they, as a rule, have to convey the gems of spiritual wisdom to the disciple by means of words (Mantras) to be meditated upon. What are these Mantras? The whole of this universe has, according to Indian philosophy, both name and form (Nâma-Rupa) as its conditions of manifestation. In the human microcosm, there cannot be a single wave in the mind-stuff (Chittavritti) unconditioned by name and form. If it be true that nature is built throughout on the same plan, this kind of conditioning by name and form must also be the plan of the building of the whole of the cosmos.