Lcang skya rol pa’i rdo rje’s Lta mgur is a work that vividly expresses the truth of dependent origination (rten ’byung) and emptiness (stong pa nyid) of the Madhyamaka school by using metaphorical expressions like “mother,” which is for emptiness, and “brother” or “father,” both of which are for dependent origination. According to him, an entity that arises dependently on others and appears in the mind is the transformation (rnam ’gyur) of emptiness or “mother.” Ordinary people, however, do not perceive the emptiness of an entity and hence wrongly understand that it is established by its own being. What is to be negated is a thing’s establishment by means of its own being (rang bzhin gyis grub pa), which appears in the minds of ordinary people as something inseparable from that thing. The negation of the object of negation through reasoning enables one to attain the Madhyamaka insight, on the basis of which the cognition of an entity that entails the cognition of emptiness is obtained. It is at this moment that the union of appearance and emptiness (snang stong zung ’jug) is cognized. Lcang skya rol pa’i rdo rje emphasizes the point that it is precisely because every entity is the transformation of emptiness that abandonment of suffering and liberation from sam˙ sa¯ra are possible. He says that one can find salvation only with the benefit of “mother,” namely, emptiness.
The characteristic feature of the Lta mgur is that it describes such topics as the nature of the object of negation, the union of appearance and emptiness, etc., which are extensively discussed by Tsong kha pa, on the basis the author’s own personal experience. The highly sophisticated scholasticism that is characteristic to the Dge lugs pa’s monastic universities is alien to the Lta mgur. This is probably the reason that is has been widely accepted in both Dge lugs pa and non-Dge lugs pa schools. We may say that this is the work that embodied the unity of the Madhyamaka philosophy and poetic literature of the Dge lugs pa tradition, and also that triggered the non-sectarian (ris med) movement flourishing in the nineteenth century.