A philosophical language is any constructed language that is constructed from first principles or certain ideologies. It is considered a type of engineered language. Philosophical languages were popular in Early Modern times, partly motivated by the goal of recovering the lost Adamic or Divine language. The term ideal language is sometimes used near-synonymously, though more modern philosophical languages such as Toki Pona are less likely to involve such an exalted claim of perfection. It may be known as a language of pure ideology. The axioms and grammars of the languages together differ from commonly spoken languages today.
Overview
In most older philosophical languages, and some newer ones, words are constructed from a limited set of morphemes that are treated as "elemental" or fundamental. "Philosophical language" is sometimes used synonymously with "taxonomic language", though more recently there have been several conlangs constructed on philosophical principles which are not taxonomic. Vocabularies of oligosynthetic languages are made of compound words, which are coined from a small set of morphemes; languages like Toki Pona similarly use a limited set of root words but produce phrases which remain series of distinct words. Toki Pona is based on minimalisticsimplicity, incorporating elements of Taoism. Láadan is designed to lexicalize and grammaticalize the concepts and distinctions important to women, based on muted group theory. A priori languages are constructed languages where the vocabulary is invented directly, rather than being derived from other existing languages. Philosophical languages are almost all a priori languages, but most a priori languages are not philosophical languages. For example, Quenya, Sindarin, and Klingon are all a priori but not philosophical languages: they are meant to seem like natural languages, even though they have no genetic relation to any natural languages.
History
Work on philosophical languages was pioneered by Francis Lodwick, Sir Thomas Urquhart, George Dalgarno, and John Wilkins. Those were systems of hierarchical classification that were intended to result in both spoken and written expression. In 1855, English writerGeorge Edmonds modified Wilkins' system, leaving its taxonomy intact, but changing the grammar, orthography and pronunciation of the language in an effort to make it easier to speak and to read. Gottfried Leibniz created lingua generalis in 1678, aiming to create a lexicon of characters upon which the user might perform calculations that would yield true propositions automatically; as a side effect he developed binary calculus. These projects aimed not only to reduce or model grammar, but also to arrange all human knowledge into "characters" or hierarchies. This idea ultimately led to the Encyclopédie, in the Age of Enlightenment. Under the entry Charactère, D'Alembert critically reviewed the projects of philosophical languages of the preceding century. After the Encyclopédie, projects for a priori languages moved more and more to the fringe. Individual authors, typically unaware of the history of the idea, continued to propose taxonomic philosophical languages until the early 20th century. More recent philosophical languages have usually moved away from taxonomic schemata, such as 21st centuryIthkuil by John Quijada.
