Some researchers accredit humankind as the discoverers of the first sign language. Early man, before spoken language, most likely made use of gesture signs. They indicated and formed signs for those things they could not discuss. In this way, early man was doubtless the first discoverers and users of the most primitive sign language.

However, a few people believe that Juan Pablo de Bonet discovered sign language. In 1620, Pablo published a book, which had the first known manual alphabet system.