Tattvacintāmaṇi

Tattvachintamani is a treatise in Sanskrit authored by 14th-century CE Indian logician and philosopher Gangesa (fl. c. 1325). The title may be translated into English as "A Thought-jewel of Truth." The treatise is also known as Pramāṇa-chintāmaṇi ("A Thought-jewel of Valid Knowledge").

The treatise introduced a new era in the history of Indian logic. Satis Chandra Vidyabhusana in his authoritative 681-page history of Indian logic divided the millennia long history of Indian logic into three sometimes-overlapping periods: Ancient period (650 BCE100 CE), Medieval period (1001200 CE) and Modern period (from 900 CE). He also identified certain standard work as typical representative of each of these periods. Tattvachintamani of Gangesa is the text identified as the standard work of the Modern period in the history of Indian logic, the standard works for the earlier periods being Nyāya Sūtra by Akshapāda Gautama (Ancient period) and Pramāṇa-samuccaya by Dignāga (Medieval period). The fact that Tattvachintāmaṇi was highly popular is attested by the appearance of numerous commentaries that have been produced in the centuries that followed the appearance of the book. It has been estimated that while the original text of Tattvachintāmaṇi has about 300 pages, all the commentaries put together contain about a million (10 lakh) pages.