A standard international language should not only be simple, regular, and logical, but also rich and creative.
Edward SapirA common allegiance to form of expression that is identified with no single national unit is likely to prove one of the most potent symbols of the freedom of the human spirit that the world has yet known.
Edward SapirWere a language ever completely "grammatical" it would be a perfect engine of conceptual expression. Unfortunately, or luckily, no language is tyrannically consistent. All grammars leak.
Edward SapirAs a matter of fact, a national language which spreads beyond its own confines very quickly loses much of its original richness of content and is in no better case than a constructed language.
Edward Sapir