 The earliest known example of the canonical Indian syllogism is found in the Caraka-saṃhitā. The argument is clearly an analogical one. The earliest known deductive version of the syllogism is found in the Fāng biàn xīn lùn, or Upāya-hṛdaya; and the earliest known discussion of a deductive version of the syllogism is found in the Rúshí lùn, usually referred to as the Tarka-śāstra. A concise version of the the deductive version is found in Vasubandhu’s Vāda-vidhi.