インド論理学における遍充概念の生成と発展 : チャラカ・サンヒターからダルマキールティまで

The Origin and Development of the Concept of Vyāpti in Indian Logic : from the Carakasaṁhitā upto Dharmakīrti

Katsura Shoryu

広島大学文学部紀要. 特輯号

The Hiroshima University studies, Faculty of Letters, Special Issues

The main aim of this article is to trace the history of the concept of 'logical connec-ion' in Indian logic. At the outset it is to be noted that there were two traditions of Indian logic, viz. the vāda tradition which was primarily concerned with the various rules of a debate and the pramāṇa tradition which examined what the valid means of knowledge were. Regarding inferential knowledge, the early sources of the vāda tradition, such as the Carakasaṃhitā and the Nyāyasūtra, merely list different kinds of inference without mentioning any notion of 'logical connection' which underlies the inferential process. It is in the early texts of the pramāṇa tradition, such as the Vaiśeṣikasūtra and the Ṣaṣṭitantra (of the Sāṃkhya school), that one first comes across the concept of 'logical connection'. Both texts list several types of 'relation' (sambandha) as the foundations of inference, e.g. causal relation, inherence (samavāya), the owner-property relation, etc. The Ṣaṣṭitantra seems to have exerted a great influence upon the following generations of Indian logicians, including Buddhist logicians like Asanga.

Next comes Vasubandhu who for the first time employed the concept of 'necessary or inevitable' relation (nāntarīyakatva/avyabhicāra/avinābhāva) as the foundation of inferential knowledge. Unlike the ontological relations enumerated in the Vaiśeṣikasūtra and the Ṣaṣṭitantra, Vasubandhu's notion of 'relation' can be regarded as abstract and logical, so that his inference may be more universally applicable.

Dignāga at last succeeded in combining the two traditions of Indian logic into one unified system. He was the first one who introduced the concept of 'pervasion' (vyāpti) in order to structually ensure the 'necessary relation' (avinābhāva). It is quite certain that Dignāga's notion of vyāpti stemed from the Grammarian's notion of avadhāraṇa/niyama (limitation/restriction) which was regarded by them as the function of the restictive particle eva. In our universe of discourse, when the domain of probans (liṅga) is limited/restricted by the domain of probandum (liṅgin), the former is included in and pervaded by the latter. Such a structure can be expressed in the Sanskrit language by attaching the particle eva to the restricting element or 'pervader' (vyāpaka), i.e. probandum. Dignāga must have been quite fond of employing the restrictive particle. There are a few other cases. For example, although the triple criterion of the valid probans (trairūpya) had been known even to Asaṅga, it was Dignāga who introduced the particle eva in the second and third formulae of trairūpya, so that the necessary connection between probans and probandum could be sucessfully expressed. Another example is that regarding the formula of 'example' (dṛṣṭānta) in a formal proof, Dignāga insists that the term expressing probandum must be followed by the particle eva, so that the pervasion (vyāpti) is properly expressed in that formula.

Post-Dignāga Indian logicians, such as Praśastapāda and Kumārila, generally accepted Dignāga's logic. Although Uddyotakara strongly criticized Dignāga on every point, it cannot be denied that he too was much influenced by Dignāga. Finally, in the development of the notion of 'logical connection' Dharmakīrti introduced the concept of 'essential connection' (svabhāvapratibandha) in order to explain away the 'pervasion' in our universe of discourse on the basis of our world of real experience.

Oriental thought [ 120 ]

jpn

広島大学文学部

[NCID] AN00163013