As a follow-up to these posts:
viewtopic.php?f=2&t=173182&start=25#p2179919
viewtopic.php?f=2&t=173182&start=25#p2179926
Do we want a world language, permitting us all to communicate with one another effortlessly? Proponents argue it would enable us to share ideas and appreciate our shared humanity with others who are a mystery to us at the moment. It would ease trade and simplify the spread of information - and information is a currency of its own. In philosophy, where precise meanings are of the essence, and anglophone western philosopher could share thoughts with a professor of Confucian thought in Beijing.
Language doesn’t entirely define all of the concepts we can handle, as the Sapir-Whorf hypothesis implies (http://www.mnsu.edu/emuseum/cultural/language/whorf.html) - otherwise translations and new coinages would be impossible, or at least very difficult. We have a capacity for metaphor, metonymy, synecdoche and other lateral shifts away from our mother tongue. We’re bright enough as English speakers to understand the difference (given explanation) between the German wissen and kennen for which we have only “to know”, or the French plaisir and jouissance for which we have “pleasure”. Schadenfreude is a recognisable feeling even without knowing the word for it.
On the other hand, fundamental grammar does shape the way we think of things and perceive the world. In some cases, very lightly - whether a fork has a gender or not - in other cases, more so. Many languages have inflections or verbs for knowing that communicate how certainly something is known; English has a complicated tense structure that baffles many non-native speakers, and to get English conditionals right every time you more or less have to be a well-educated native speaker (if you hadn’t have been born a native speaker, you might never have been able to have written this sentence correctly). See also the aboriginal language linked to in the first link.
One sees a lot of misunderstandings in philosophy due to linguistic assumptions. Particularly in epistemology and philosophy of mind, where the mere grammatical appearance of a noun or gerund (“an idea” or “his incomprehension”) tempts one to think of objects floating around in a mystical-physical space, or the use of verbs (like “to know” or “to understand”) become misinterpreted as mental processes rather than capacities, abilities or dispositions. Common idioms and metaphors reveal the inherent assumptions of a language.
A shared language would channel us all into its assumptions and weaknesses. While people remained bilingual it may not be such an issue, but a ‘brotherhood of man’ with no external linguistic perspective may just forget that other languages are a possibility. You already see this with some Anglophones who, isolated from other cultures, struggle to comprehend that some foreigners just don’t speak English.
A third option is a written/symbolic language that people can read in their own language. As an extension of Pali, in the following link:
tnr.com/book/review/tongues-twisted
The problem being then that the translation-step still remains - plaisir/jouissance as against pleasure; different contextual meanings and implications of the same word, relative to other languages; tense structures or grammatical cases that simply do not exist for many languages. It would have to be either the most complex language in the world, or a stripped-down simple childspeak.
This isn’t a case of scepticism, although there’s reason enough - Esperanto has already failed, the English language almost certainly won’t even permit a spelling rationalisation, languages are very conservative as they’re so intimately connected with culture and hence identity. Keeping languages will maintain different cultures, different aims, struggles and potentially violent conflict. But at the same time it maintains diversity, flexibility, robustness of thought as a whole across humanity; each linguistic gap acts as a bulkhead to dogma and unquestioned assumptions. Inefficient, but all the stronger for it.