因明入正理論疏 1.5

1.5

First, as for relating the background causes: regarding the treatises on hetuvidyā, their source originated solely from the Buddha's preaching, but the text was vast and the meanings scattered, being present across the various sūtras. Thus the Bhūmidhāra says: 'When a bodhisattva seeks the Dharma, where should he seek it? He should seek it in all five sciences.' One seeks hetuvidyā in order to refute heterodox treatises and establish the orthodox path. At the beginning of the kalpa, Akṣapāda first established the genuine and the semblance. Down to Vasubandhu, all laid out the rules and formulas. Although the guidelines were set forth, the profound subtleties had not yet been analyzed; therefore, when opponents and proponents debated, they still doubted the rules of proof and refutation.