1000 B.C.: Hebrew Law denies the rights of Deaf people. It did not allow Deaf people the right to ownership of property. Ref.
384-322 B.C.: Ancient Greek philosopher, Aristotle, pronounced that Deaf people could not be educated without hearing ("it is impossible to reason without the ability to hear"). He says, "Those who are born deaf all become senseless and incapable of reason."
427-347 B.C.: Ancient Greek philosopher Plato believes in his book "Plato's Cratylus" that all people were born with innate intelligence and it must be nurtured or developed. Without speech, deaf people had primitive thoughts.
345-550 AD: St. Augustine told early Christians that deafness is a punishment from God.
In the 16th century, Geronimo Cardano, a physician of Padua, in northern Italy, proclaimed that deaf people could learn and understand via sign communication. Ref.
"In France, a Spanish alphabet of the 16th century was embodied through the labours of Pereira and his deaf pupil Saboureaux de Fontenay, from the original work of the Benedictine monk, Pedro Ponce de Leon (1520-84)." (Cristhley, p. 33)
"Rather earlier the way was prepared by the teachings of Jerome Cardano (1501-75), who rebelled against the current acceptance of Aristotle's teaching, that connected thought was impossible without speech." (Critchley, p. 33)
This kind of thinking dated back to the ancient Greek is a part of logocentrism and phonocentrism discussed by French philosopher Derrida (on speaking and writing). Phonocentrism is largely responsible for the struggles between hearing people (speech-centered education, language as central to speech) and deaf people (natural language-centered) on education, human rights, and so on since then.
Related links: Timeline: 16th century.