It is often said that languages for specific purposes (also named special languages or technolects) are the product of a division of labor. Although this concept was introduced only as late as 1776 (by Adam Smith, in An Inquiry Into the Nature and Causes of the Wealth of Nations), the idea that professions or occupations of all kind are characterized by a particular vocabulary that is not understood by all native speakers was already manifest in the writings of medieval scholars (for instance, in Dante’s De vulgari eloquentia). In the Middle Ages most Romance languages conquered a more or less wide range of domains. The question arose whether they were also appropriate to serve as a medium of scholarship. The disciplines taught at the universities (arts, theology, law, medicine) had a strong Latin tradition; their knowledge was popularized by means of translations, which enriched the vocabulary and the syntactic flexibility of the emerging languages. Thus, the translators—sometimes organized in “schools”—contributed to the elaboration of the target languages and to their emancipation from Latin. Aside from the septem artes liberales, however, a second group of (seven) disciplines without Latin roots (called artes mechanicae) established and introduced mainly native vocabulary typical of the respective occupational fields. During the first centuries of modern times, more and more scholars felt that their mother tongue should take the place of Latin as a means of propagating scholarship and new findings. In the 17th and 18th centuries, French held the lead among the modern languages in nearly all fields of knowledge; it maintained its dominant position among the Romance languages until the second half of the 20th century. On a global level, German was a strong rival in the humanities and several scientific disciplines in the 19th century; for many decades, however, English has been the universal medium of communication in the scientific community. This process has given rise to many discussions about language planning measures to be taken in order to curtail the Anglo-American supremacy. Before the 18th century, special languages did not have a strong impact on the physiognomy of developed languages. In the sphere of academic disciplines, translations of canonical Latin texts entailed a general re-Latinization and, as a consequence, a process of convergence of the Romance languages. The technical languages of trade and artisanry were highly fragmented so that their special vocabulary was used and understood only in limited geographical areas. In the Age of Enlightenment, the growing prestige of experts, on the one hand, and philosophical considerations about the optimization of language(s), on the other hand, led to increasing harmonization efforts on national and supranational levels. Organizations were founded with the purpose of creating and standardizing terminologies for various kinds of subjects (technical products, medicine, etc.). Special languages, far from being homogeneous varieties, are differentiated vertically. Linguists use to distinguish between three levels of communication: specialists inter se (e.g., physician—physician), specialist—skilled worker (physician—nurse), and specialist—layman (physician—patient). Studying how technical terms seep into common language and what changes they undergo during this process is a great challenge for linguists.