Five Terton Kings
Causal and resultant vehicles (rgyu dang 'bras bu'i theg pa).
The teachings of Hinayana and Mahayana that regard the practices of the path as the causes for attaining the fruition of liberation and enlightenment and the Vajrayana system of taking fruition as the path by regarding buddhahood as inherently present and the path as the act of uncovering the basic state. [RY]
The great master Longchenpa defined them as follows: "The causal vehicles are so called because of accepting a sequence of cause and effect, asserting that buddhahood is attained by increasing the qualities of the nature of the sugata essence, which is merely present as a seed, through the circumstance of the two accumulations. The resultant vehicles are so called because of asserting that the basis for purification is the (sugata) essence endowed with qualities that are spontaneously present as a natural possession in sentient beings, just as the sun is endowed with rays of light; that the objects of purification are the temporary defilements of the eight collections (of consciousnesses), like the sky being (temporarily) obscured by clouds; and that one realizes the result of purification, the primordially present nature, by means of that which purifies, the paths of ripening and liberation. Besides this, there is no difference (between the two) in sequence or quality." [RY]