Prajñā as Observation in the Heart Sūtra

This paper examines the Heart Sūtra by rearticulating prajñā not as a cognitive achievement or doctrinal insight, but as an operative mode of observation (觀) enacted within practice. Rather than approaching the text as a summary of emptiness doctrine or as an ontological declaration, the study analyzes how the Heart Sūtra internally organizes observation through a highly compressed structure governed by pivot, boundary, and closure mechanisms. Focusing on the pivotal statement "是諸法空相," the paper argues that emptiness is not presented as a metaphysical negation of existence but as a functional marker that blocks the substantialization of marks (相). The successive negation sequence (無…) is examined not as a list of denied entities, but as a set of boundary conditions that interrupt cognitive pathways through which phenomena are reified as attainable objects. Particular attention is given to the transition from "無智亦無得" to "以無所得故," which structurally fixes the target of negation as the reification of wisdom and attainment themselves. The placement of "無罣礙…究竟涅槃" and the concluding mantra is further interpreted as a closure device that marks completion of an observational trajectory while enabling its repetition within recitative transmission. Methodologically, the paper takes into account conditions of oral transmission and repeated recitation prior to extensive textualization. Under such conditions, meaning may be stabilized not only through discursive explanation but through procedural constraints embedded in rhythmic repetition. The durability of list structures, parallel negations, and closure formulas is therefore treated as integral to the text's capacity to transmit an operative mode of observation rather than a doctrinal proposition. By formalizing prajñā as regulated observation enacted through constraint-based textual design, this study provides a structural account of the Heart Sūtra as a practice-oriented text. It serves as a foundational analysis for the integrative reconstruction developed in Reconstructing the Relationship Between the Heart Sūtra and the Diamond Sūtra, where the operative logic identified here is placed in direct relation to the expanded verification and correction structures of the Diamond Sūtra. This study constitutes the foundational analysis on which the integrative reconstruction presented in Reconstructing the Relationship Between the Heart Sūtra and the Diamond Sūtra is based.