<p>The evolution of Indian Buddhism showcases a significant transformation in epistemological frameworks, departing from the foundational concepts of early Buddhism. Initially grounded in phenomenology and process metaphysics, early Buddhist thought emphasized the unfolding of experience over time. However, the advent of the Abhidhamma introduced a shift towards event based metaphysics, focusing on discrete moments rather than continuous processes. This shift stemmed from reductionist methodologies in the Abhidhamma, which analyzed experiences systematically, leading to the theory of momentariness that views reality as fleeting events instead of enduring substances. Consequently, concepts of temporal consciousness evolved from extensional frameworks to more mechanistic models, illustrated by the Sautrantika’s view of discrete experiences and the Sarvastivadin’s notion of tri temporal existence. The implications of this philosophical shift significantly impacted the understanding of karmic rebirth. Karma, once fluid, was reinterpreted as discrete events, altering the theoretical landscape of Indian Buddhism and its practical implications for followers. Buddhaghosa’s commentary, the Visuddhimagga, articulated a theory of momentariness, particularly emphasizing death-threshold karma’s role in rebirth. To reconcile the continuity of karma with the notion of momentariness, Buddhaghosa introduced “duration less duration,” drawing on a tri temporal framework that integrates past, present, and future moments. This synthesis aimed to provide a holistic understanding of the rebirth process within Buddhist philosophy.</p>