The pure language is the one without words.
Surprised? Don't be. If "communication" is the activity of clearly conveying information, and if "language" is the accepted medium, then we cannot afford to miss the language without words. And we certainly cannot afford not to understand it. For, nothing can ever be "communicated" better with words than without.
Languages have evolved over time. Words have been borrowed and lent; idioms and pharases have been "coined"; lexicons continue to be revised. Have languages really improved? Or have they only become more and more complex with time?
For instance, look at these sentences:
"The chicken is ready for lunch" and "The children are ready for lunch"
"A jail is a prison" but "A jailer is not a prisoner"
Now, let us consider a word at random: Is "Crib" a verb or a noun?
In "crib a construction hole", crib is a verb, which means "line with beams or planks".
To crib is also to cheat, to copy or to steal.
As a noun, crib could be a baby bed with high sides made of slats, it could be a bin or granary for storing grains, or it could mean the cards discarded by players at cribbage.
In cryptanalysis, a crib is a sample of known plaintext.
In addition to the above, we also have to be concerned with issues such as differences in accents, cultural influences that alter the definition of words or even sentences, idiosyncrasies of spellings, "twists" of grammar, infiltration of "slangs", to name only a few.
What, then, is the result of evolution? Firstly, we are unsure of communicating what we are trying to. Secondly, our "medium" with words is not "pure".
"Lingua Pura" is the one that has no words, it depends on no words to convey information. Therefore, it can convey clearly, it can convey exactly. It is the one true "universal" language.