In Europe, logic was revived in the mid-nineteenth century, at the beginning of a revolutionary period when the subject developed into a rigorous and formalistic discipline whose exemplar was the exact method of proof used in mathematics. By the sixteenth century, several developments in modern logic had been anticipated by the Indian and Islamic traditions, both of which influenced the revival of logic in 19th century Europe. In the Islamic tradition, numerous texts were written on Avicennian and Post-Avicennian logic, while in India, this same period was a high point which saw the foundation of the Navya-Nyaya school. The period between the late fourteenth century and the beginning of the nineteenth century was largely one of decline and neglect, and is generally regarded as barren by historians of logic, at least in regards to the European tradition, which was dominated by Aristotelianism. The word logic (from the Greek logos, meaning discourse or sentence) does not appear in the modern sense until the commentaries of Alexander of Aphrodisias, writing in the third century AD.Īristotelian logic was further developed by medieval Islamic and then European logicians, reaching a high point in the mid-fourteenth century. Logic was known as dialectic or analytic in ancient Greece. Of these three, only the Greek and Indian traditions had survived into early modern times. An explicit analysis of the principles of reasoning was initially developed in three traditions: Indian logic, Chinese logic, and Greek philosophy. Many cultures have employed intricate systems of reasoning, and logical methods are evident in all human thought. The history of logic is the study of the development of the science of valid inference ( logic).