Logic

by

Sundar Sarukkai

• LAST REVIEWED: 25 February 2016
• LAST MODIFIED: 25 February 2016
• DOI: 10.1093/obo/9780195399318-0164

Introduction

Indian logic is primarily a study of the nature of human inference, and its beginnings can be traced back to ancient times. It is indeed remarkable that over the span of millennia the study of logic across the many different philosophical schools, each with their own unique metaphysical presuppositions, exhibits many common characteristics as well as some unique differences. Perhaps the dominant reason for this is the continued debate between these different traditions whereby it was incumbent upon the followers of each school to understand and summarize their opponents’ position. Almost all these philosophical schools had their own formulations of debate, core metaphysical theses, and the arguments that related these to the standard formulations in logic, epistemology, and ontology. The earliest work on logic is often traced back to the early Nyāya tradition and the early Buddhist tradition of Catuṣkoṭi. These logical formulations were part of the logical debates in Sāṅkhya, Mīmāṃsā, and the Vedantic traditions. A significant shift in the formulation of the logical argument, through the language of sign and signifier, can be found in Diṅnāga’s formulation, which then became standard for other philosophical traditions. There is also quite a radical difference in the way the Jainas analyzed logic. Along with the history of these logical traditions, some important conceptual categories across these schools will also be highlighted.

History of Indian Logic

Vidyabhusana 1920 suggests a classification of Indian logic into ancient, medieval, and modern periods. Each of the many Indian philosophical schools had their own unique take on the analysis of inference, and thus there is an extensive amount of interschool debates about logic and the terms that arise in them. Matilal 1990 is a good source for a historical and accessible account of these topics. Preisendanz 2009 is a textual analysis of an important medical text, Carakasaṃhitā, and points to its similarity with the primary text of the early Nyāya, the Nyāyasūtra. Wada 2000 goes through the different claims to the authorship of the Navya-Nyāya and through this gives a glimpse of the complex task of reconstructing histories of this tradition. The five-volume set on history of Indian philosophy by Dasgupta 1922 is useful for a broad introduction to the evolution of philosophy in India, and since logic was an essential component of this process, these volumes give a good insight into the motivations behind the development of Indian logic. Similarly, the many-volume encyclopedia by Potter and his co-editors are a classic resource (Potter 2014); their classification of the volumes in terms of particular schools and within each volume in terms of major texts and philosophers makes these volumes a very useful and easily accessible resource. Ganeri 2001 is a collection of seminal papers on the reception and interpretation of Indian logic, largely by European scholars starting from 19th century.

• Dasgupta, Surendranath. A History of Indian Philosophy. 5 vols. New York: Cambridge University Press, 1922.

  Extremely useful compilation of sources, both historical and conceptual, on Indian philosophy. Given the essential relationship between logical themes and philosophical themes such as epistemology and metaphysics, a broader history of Indian philosophy is useful to understand the history of Indian logic.

• Ganeri, Jonardon, eds. Indian Logic: A Reader. New York: Routledge, 2001.

  A collection of influential articles from the 19th century on interpretation of Indian logic; gives an indication of the initial reception to the particularities of Indian logic in Europe.

• Matilal, B. K. Logic, Language and Reality: Indian Philosophy and Contemporary Issues. Delhi: Motilal Banarsidass, 1990.

  Very useful and readable account of the different types of inference in early Nyāya and other schools. This book is also useful in that a broad range of topics are covered both in depth and breadth. See also Role of Samśeya (Doubt) and Vāda (Debate) and Hetvābhāsa (Fallacies), Lakṣaṇa (Definition), and Upādhi (Undercutting Conditions)

• Potter, Karl, ed. Encyclopedia of Indian Philosophies. 20 vols. Delhi: Motilal Banarsidass, 2014.

  Organized very well in terms of traditions, themes, and philosophers. Has a wealth of historical details as well as attention to major and minor conceptual issues.

• Preisendanz, Karin. “Logic, Debate and Epistemology in Ancient Indian Medical Science: An Investigation into the History and Historiography of Indian Philosophy.” Indian Journal of History of Science 44 (2009): 261–312.

  An in-depth analysis of the apparent relation between Carakasamhita and Nyāyasūtra; places the development of the logical tradition within a historical perspective.

• Vidyabhusana, Satis Chandra. A History of Indian Logic: Ancient, Mediaeval and Modern Schools. Delhi: Motilal Banarsidass, 1920.

  A very useful book for an overview of a chronological account of development of logic in India in different philosophical schools and has many small, interesting details. Some of these details can be patchy and have been superseded by later works, but this book still remains one of the most comprehensive and accessible introduction to Indian logic. See also Role of Samśeya (Doubt) and Vāda (Debate).

• Wada, Toshihiro. “The Origin of Navya-Nyāya and Its Place within the History of Indian Logic.” In Three Mountains and Seven Rivers: Prof Musahi Tachikawa’s Felicitation Volume. Edited by S. Hing and T. Wada, 439–463. Delhi: Motilal Banarsidass, 2000.

  Analyzes the claims to the authorship of Navya-Nyāya and considers three possible candidates. Draws on many texts about the authorship and history of Navya-Nyāya; the bibliography is itself useful.