The resulting combination, an artificial language, was over-complicated and completely unusable by his students. For example, where his system would elaborately construct the word "unintelligible" with a chain of five signs ("interior-understand-possible-adjective-not"), the deaf natural language would simply say "understand-impossible". LSF was not invented by the abbé, but his major contributions to the deaf community were to recognize that the deaf did not need oral language to be able to think, and to indirectly accelerate the natural growth of the language by virtue of putting so many deaf students under a single roof.