Is inference a cognitive or a linguistic process? A line of divergence between Jain and Buddhist classifications Marie-Hélène Gorisse, Ghent University Abstract. Theories of inference mainly consist of the study of persuasive reasoning as a reliable source of knowledge. In classical India, investigations of inference ( anumāna ) are traditionally referred to as “Indian logic” ( nyāya ) and are performed as part of the treatises on the means to acquire knowledge ( pramāṇa). As such, they lie at the junction between theories of knowledge, theories of argumentation and theories of meaning. While Buddhist and Naiyāyika theories of inference are well documented, those of the Jains still call for further study. In Jainism, the founding teachings of the Digambara master Akalaṅka (640-680) are partly devoted to drawing a clear distinction between Dharmakīrti’s conceptions and those of the Jains. These teachings have been succeeded by those of Māṇikyanandi and a tradition ranging from Prabhācandra to Vādi Devasūri. The objective of this paper is, from a study of the texts of this tradition, to understand the specificities of the Jain theory of inference, especially in relation with those of the Buddhists, which are very close. Within the framework of this paper, I will focus on the following issue: in the study of inference in both traditions, what is conceived as a cognitive process, and what as a linguistic one? This, in turn, will lead us to investigate different conceptions concerning the natural relations ensuring certainty, as well as different forms of inference. 1. The cognitive process of inference 1.1. Historic presentation Around the 2nd century BCE, the emergence of rival philosophical schools in India, and the need to preserve and strengthen their respective positions, led to the development of the genre of sūtra , along with its commentarial traditions. Already, at an early stage, this style of philosophical systematisation included refutations of rival theses, as well as refutations of attacks, or potential attacks, towards one’s own theses. This tradition of debate evolved in such a way that around the 6 th century CE, a pan-Indian inter-doctrinal consensus on what constitutes a satisfactory justification (a canonical presentation of a correct inference) was achieved. I will refer to this rich period of philosophical dialogue that occurred especially between Hindu, Buddhist and Jain schools, as the “classical” period of Indian philosophy. This period extends from the composition of the above-mentioned sūtra texts (2nd century BCE) to the Muslim invasions that mark a clear interruption to the Indian philosophical tradition around the 12th century CE. The present study is more precisely concerned with the theorising on inference by Jain philosophers. Jain philosophy is often marginalised, and a proper reintroduction of Jain philosophical ideas within the broader framework of Indian philosophy is a desideratum in scholarship. I will focus on the period following Dharmakīrti (7 th c.), a Buddhist philosopher who made breakthroughs in philosophy, especially in relation with the conception of necessity, and who addressed some virulent criticisms against Jain philosophy of knowledge. 1 At that time, the biggest challenge for Jain philosophers was to distinguish their conceptions from the conceptions of Dharmakīrti. The milestone for such a challenge is Akalaṅka’s teachings (640-680). Akalaṅka founded a systematic Jain theory of knowledge, and part of this theory is devoted to the study of inference and other logical considerations. After him, the Jain Māṇikyanandi (after 680 and before 980) organised Akalaṅka’s mature philosophy into a concise treatise, the Parīkṣāmukham (henceforth PM), the Introduction to philosophical investigation . This work has itself been commented on by the Jain Prabhācandra (980-1065) in his Prameyakamalamārtaṇḍa (PKM), the Sun that grows the lotus of the knowable . The PKM is of particular importance, first because it presents Akalaṅka’s influential teachings in a more organised and a more detailed way than his predecessors. Second, because it draws special attention to dialogues with other schools 2. The reception of the PKM exemplifies the marginalisation of Jain philosophy, because although it is an important text in the classical Indian tradition, only very small parts of it have been translated. A last name of importance is Vādi Devasūri (12 th c.), who wrote a commentary to the PKM, namely the Pramāṇanayatattvālokālaṃkāra (PNT), the Commentary on the explanation of the nature of universal and contextual knowledge . These three works constitute a lineage of commentaries, and each of them shares the same conception of inference, which I will refer to as “the tradition of Akalaṅka”. Since the PM is the first work in this line of tradition, I will mainly refer to this text, and will quote from the PKM and the PNT only when considering matters which are absent from earlier works. This Jaina tradition is very close to the Buddhist tradition as initiated by Dharmakīrti in his comments on Dignāga. Therefore, I will focus on the differences between the two conceptions, and ask the following question: “in what sense can we say that the presentation at stake is specifically Jain?” 1.2. General presentation 1 The following passage from Dharmakīrti’s Pramāṇavārttikasvavṛtti (PVs), 181.1, is a good example of his virulence against Jain philosophers: What the shameless [Jains] nonsensically profess, namely “a camel is, in a certain sense, yoghurt, [and] is not, in a certain sense, yoghurt”, [a theory] which is really primitive, inconsistent and is not relevant to what should be avoided and to what should be appropriated – insofar as it does not help establish [that which should be avoided and that should be appropriated] – [and is therefore] confused ( yad ayam ahrīkaḥ syād uṣṭro dadhi syān neti kim apy aślīlam ayuktam aheyopādeyam apariniṣṭhānād ākulaṃ pralapanti ). Translated in [Balcerowicz06], p. 1 and edited in [Gnoli60], p. 89. 2 For example, one can find in the PKM an entire text of Dharmakīrti which would have been lost otherwise, namely the Sambandhaparīkṣā (SP), the Philosophy of relations , see [Shastri90], pp. 504-511. Inference is the cognitive process by which a given subject acquires new knowledge using reasoning, in contrast with direct cognitive processes such as perception. This reasoning consists of finding which certainties one can acquire from the observation of a given phenomenon. Therefore, it lies at a junction between theories of knowledge, since investigations on inference ( anumāna ) are performed as part of the treatises on the means to acquire knowledge ( pramāṇa), and theories of argumentation, since investigations on inference mainly consist of the study of persuasive reasoning as a reliable source of knowledge. What is more, this field of expertise traditionally referred to as Indian “logic” (nyāya ), is concerned with theories of meaning as well, since one of its core issues is the question of the extension of predicates. More precisely, an inference is usually based on a relationship of inclusion between the range of two properties, although in section 2.2, we will see that Jain philosophers try to extend this conception. The example of inference provided by Māṇikyanandi is that one can acquire the knowledge that sound is subject to change as a result of one’s previous knowledge that sound is something that is produced.3 This is due to the fact that everything that is subject to change is necessarily produced, given the very meaning of “subject to change”. This process is defined as follows: PM.3.14. Inference is the knowledge of the target-property by means of the evidence-property.4 PM.3.15. The evidence-property is characterised by being always absent in the absence of the target-property.5 With anachronistic tools, the inference from the knowledge that sound is produced to the knowledge that sound is subject to change is ensured by the following relationship between the two properties involved: Target -property Evidence-property 3 pariṇāmī śabdaḥ kṛtakatvāt , [Ghoshal90], p. 127. In this paper, all translations are mine, unless stated otherwise. 4sādhanāt sādhyavijñānam anumānaṃ, [Ghoshal90], pp. 90-1. 5 sādhyāvinābhāvitvena niścito hetuḥ, ibid. This is the reason why in this case the evidence-property functions as evidence: if we know that the evidence-property is present, then we know for sure that the target-property is present too. The translation of the Sanskrit expressions sādhya by “target-property” and sādhana or hetu by “evidence-property” is motivated by the fact that in the PM, the PKM and the PNT, these two expressions are regularly substituted with, respectively, sādhyadharma and pakṣadharma . This, in turn, is a consequence of the fact that the universal relationship of pervasion that is ensuring the correctness of a given inference can happen only between properties. This is stated in: PM.3.32. But as far as the universal pervasion is concerned, what one seeks to know is always a property 6. It should be stated that what is called “Indian logic” is principally the study of inference, and the way an inference can be proved within a debate against different types of opponents. That is to say that Indian logic is interested in the knowing subject, as well as in the interactive dimension of the knowledge-acquisition process. But we should keep in mind the fact that from Frege (1848-1925) until recently, logic was conceived in the West as the science of pure relations between propositions, i.e. without any psychological consideration of a knowing subject, and that it is only in recent times that new conceptions that pay attention to the interactive dimension of proof have emerged, for example Dynamic Epistemic Logic and Dialogical Logic 7. Therefore, it is in the framework of these recent conceptions that one will find contemporary attempts to answer the types of questions that Indian philosophers also attempted to answer in their logic.