 What exactly is the Dharma, the truth that all languages and all texts point to as their mysterious source? Kūkai explicates its significance qua emptiness in terms of “primal non-origination” (Skrt: ādyanutpāda; Jpn: honpushō). What Kūkai means by “non-origination” is related to his understanding of the emptiness of things and the differential referentiality of signs. By incorporating the Mahāyāna thought of emptiness, Kūkai’s linguistic ontology of the mantra proves to be simultaneously a linguistic “an-ontology” (or: “meontology”) of sorts. Every phenomenon of the cosmos, being empty of substantiality, is what it is through its interdependent origination (Skrt: pratītya-samutpāda; Jpn: engi). Likewise each signifying letter of the cosmic text is what it is not because of its own substantial identity but rather through its difference from other signifying letters. Its identity is constituted not on the basis of a self-same essence but rather in reference to, and difference from, others. Signification then for Kūkai is nothing but differentiation (shabetsu), which is another way of speaking of the non-substantiality, i.e., emptiness, of phenomena. Every thing – rocks, mountains, ants, etc. – is what it is in mutual distinction with everything else. And this differentiation occurs via its implacement into a specific situation or context vis-à-vis other things in an endless chain of mutually referring (and differing) correlative thing-events. In reference to others and without substantial self-presence, each thing-event is hence empty. In this respect, every thing, as signifying letter, is an embodiment of emptiness. And as such a sign or letter manifesting emptiness and differential referentiality, each thing-event is thus a mantra, Dainichi’s “seal of wisdom of differentiation” (shabetsu chiin). The cosmic text constituted of mutually differing signs is then the empty place of empty things, and as such, the ultimate scripture of emptiness. The hosshin as the embodiment of this truth, the Dharma, is thus itself differentiation, emptiness.