Classical philology studies classical languages. Classical philology principally originated from the Library of Pergamum and the Library of Alexandria around the fourth century BCE, continued by Greeks and Romans throughout the Roman/Byzantine Empire. It was preserved and promoted during the Islamic Golden Age, and eventually resumed by European scholars of the Renaissance, where it was soon joined by philologies of other non-Asian (European) (Germanic, Celtic), Eurasian (Slavistics, etc.) and Asian (Arabic, Persian, Sanskrit, Chinese, etc.) languages. Indo-European studies involves the comparative philology of all Indo-European languages.
Philology, with its focus on historical development (diachronic analysis), is contrasted with linguistics due to Ferdinand de Saussure's insistence on the importance of synchronic analysis. The contrast continued with the emergence of structuralism and Chomskyan linguistics alongside its emphasis on syntax.
The term "philology" is derived from the Greek φιλολογία (philología), from the terms φίλος (phílos) "love, affection, loved, beloved, dear, friend" and λόγος (lógos) "word, articulation, reason", describing a love of learning, of literature, as well as of argument and reasoning, reflecting the range of activities included under the notion of λόγος. The term changed little with the Latin philologia, and later entered the English language in the 16th century, from the Middle French philologie, in the sense of "love of literature".
The adjective φιλόλογος (philólogos) meant "fond of discussion or argument, talkative", in Hellenistic Greek, also implying an excessive ("sophistic") preference of argument over the love of true wisdom, φιλόσοφος (philósophos).
As an allegory of literary erudition, philologia appears in fifth-century postclassical literature (Martianus Capella, De nuptiis Philologiae et Mercurii), an idea revived in Late Medieval literature (Chaucer, Lydgate).
The meaning of "love of learning and literature" was narrowed to "the study of the historical development of languages" (historical linguistics) in 19th-century usage of the term. Due to the rapid progress made in understanding sound laws and language change, the "golden age of philology" lasted throughout the 19th century, or "from Giacomo Leopardi and Friedrich Schlegel to Nietzsche". In the Anglo-Saxon world, the term philology to describe work on languages and literatures, which had become synonymous with the practices of German scholars, was abandoned as a consequence of anti-German feeling following World War I. Most continental European countries still maintain the term to designate departments, colleges, position titles, and journals. J. R. R. Tolkien opposed the nationalist reaction against philological practices, claiming that "the philological instinct" was "universal as is the use of language". In British English usage, and in British academia, "philology" remains largely synonymous with "historical linguistics", while in US English, and US academia, the wider meaning of "study of a language's grammar, history and literary tradition" remains more widespread. Based on the harsh critique of Friedrich Nietzsche, US scholars since the 1980s have viewed philology as responsible for a narrowly scientistic study of language and literature.