Sign language: Its history and contribution to the understanding of the biological nature of language

Abstract

The development of conceptualization of a biological basis of language during the 20th century has come about, in part, through the appreciation of the central nervous system's ability to utilize varied sensory inputs, and particularly vision, to develop language.
Sign language has been a part of the linguistic experience from prehistory to the present day. Data suggest that human language may have originated as a visual language and became primarily auditory with the later development of our voice/speech tract. Sign language may be categorized into two types. The first is used by individuals who have auditory/oral language and the signs are used for special situations, such as communication in a monastery in which there is a vow of silence. The second is used by those who do not have access to auditory/oral language, namely the deaf.
The history of the two forms of sign language and the development of the concept of the biological basis of language are reviewed from the fourth century BC to the present day.
Sign languages of the deaf have been recognized since at least the fourth century BC. The codification of a monastic sign language occurred in the seventh to eighth centuries AD. Probable synergy between the two forms of sign language occurred in the 16th century. Among other developments, the Abbey de L'Epée introduced, in the 18th century, an oral syntax, French, into a sign language based upon indigenous signs of the deaf and newly created signs. During the 19th century, the concept of a "critical" period for the acquisition of language developed; this was an important stimulus for the exploration of the biological basis of language. The introduction of techniques, e.g. evoked potentials and functional MRI, during the 20th century allowed study of the brain functions associated with language.

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ORIGINAL ARTICLE
Sign language: Its history and contribution to the understanding of
the biological nature of language
ROBERT J. RUBEN
Department of Otolaryngology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, USA
Abstract
Conclusion. The development of conceptualization of a biological basis of language during the 20th century has come about,
in part, through the appreciation of the central nervous system’s ability to utilize varied sensory inputs, and particularly
vision, to develop language. Objective. Sign language has been a part of the linguistic experience from prehistory to the
present day. Data suggest that human language may have originated as a visual language and became primarily auditory with
the later development of our voice/speech tract. Sign language may be categorized into two types. The first is used by
individuals who have auditory/oral language and the signs are used for special situations, such as communication in a
monastery in which there is a vow of silence. The second is used by those who do not have access to auditory/oral language,
namely the deaf. Material and methods. The history of the two forms of sign language and the development of the concept of
the biological basis of language are reviewed from the fourth century BC to the present day. Results. Sign languages of the
deaf have been recognized since at least the fourth century BC. The codification of a monastic sign language occurred in the
seventh to eighth centuries AD. Probable synergy between the two forms of sign language occurred in the 16th century.
Among other developments, the Abbey de L’E
´
pe´e introduced, in the 18th century, an oral syntax, French, into a sign
language based upon indigenous signs of the deaf and newly created signs. During the 19th century, the concept of a
‘‘critical’’ period for the acquisition of language developed; this was an important stimulus for the exploration of the
biological basis of language. The introduction of techniques, e.g. evoked potentials and functional MRI, during the 20th
century allowed study of the brain functions associated with language.
Keywords: Deaf education, history, linguistics, monastic signs, sign language, Socrates
Introduction
The human being has survived, in the Darwinian
sense, through the development and, if compared to
all other species, hypertrophy of language. The
human central nervous system has evolved to allow
for this specialization.
There is Paleolithic evidence that visual-based
language occurred before auditory [1]. This hypoth-
esis comes, in part, from evidence that there was
linguistic communication before the voice/speech
tract evolved into a form that allowed for articulated
auditory communication [2]. Ontological data [3]
demonstrate that the infant can utilize visual and
auditory linguistic inputs equally. These, and other,
streams of evidence indicate that human language is
not dependent on any particular sensory input but
can and does develop when there is appropriate
linguistic flux from any sensory modality. The
enablement of language in the deaf relies on visual
sensory inputs.
The ability of a congenitally deaf person to
acquire language through a ‘‘non-traditional’’ sen-
sory mode, vision, was not widely appreciated or
recognized until the 16th century. The story of
this belated recognition and utilization of the
human central nervous system’s intrinsic character-
istics of redundancy and plasticity is the subject of
this paper.
Indigenous sign language: fifth century BC to
sixth century AD
The deaf utilized sign language from at least the 4th
century BC, as evidenced by the statements of
Socrates in Plato’s Cratylus [4]:
Correspondence: Robert J. Ruben, MD, FACS, FAAP, Department of Otolaryngology, Montefiore Medical Center, Albert Einstein College of Medicine, 3400
Bainbridge Avenue *
/3rd floor, Bronx, NY 10467-2490, USA. E-mail: ruben@aecom.yu.edu
Acta Oto-Laryngologica, 2005; 125: 464/467
(Received 8 September 2004; accepted 9 September 2004)
ISSN 0001-6489 print/ISSN 1651-2551 online # 2005 Taylor & Francis
DOI: 10.1080/00016480510026287

‘‘And let me ask another question: if we had no
faculty of speech, how should we communicate
with one another? Should we not use signs, like
the deaf and dumb? The elevation of our hands
would mean lightness; heaviness would be ex-
pressed by letting them drop. The running of any
animal would be described by a similar movement
of our own frames ...’’
‘‘Suppose that we had no voice or tongue,
and wanted to communicate with one another,
should we not, like the deaf and dumb, make
signs with the hands and head and the rest of the
body?’’
An earlier depiction of sign language is repre-
sented by a fifth century BC Greek vase showing
Philomela, whose tongue was cut by King Tereus of
Thrace, using signs. Another early documentation of
the use of visual communication is the Roman coin,
the tessera, where fingers were used to show
numbers.
Monastic signs and the deaf from the sixth to
16th centuries
The earliest known description of a hand alphabet
is that of Saint Bede (fifth to sixth centuries)
who developed or described a system for visual
communication that was used by religious commu-
nities that had taken a vow of silence [5]. Saint
Bonaventure (13th century), as noted in Melchor de
Yedra’s 1593 Refugium infirmorum , had developed a
finger alphabet [6]. Hand signs were widely used,
especially in the Benedictine communities. The
promulgation and maintenance of this form of
communication were probably the basis of the
application of manual language to the deaf in the
16th century.
During the next centuries, there are occasional
references to the use of non-verbal manual
communication by the deaf. One of these was the
recognition of the deaf’s right to the assent of
marriage by the Spanish King Alfonso X (13th
century) [7]:
‘‘Signs that demonstrate consent among the mute
do as much as words among those who speak.’’
Another reference is that of Rodolfo Phrisii
Agricolae (15th century), who in his 1521 De
inventiuone dialectica noted a person ‘‘ ‘deaf from
the cradle and by consequence mute’ who could
express his thoughts and understand those of others
by way of writing’’ [7].
Application of signs for aid in teaching the deaf:
16th to 17th centuries
Up to the 17th century, the Aristotelian concept that
hearing conveyed sound, which was assumed to be
the basis of thought and by inference language, was
the tenet by which the deaf, usually those with
congenital or early-onset deafness, who could not
speak, were considered uneducable. The religious
canons were congruent with this concept of an
inability to think or use language, as written in the
Talmud [8]:
‘‘A deaf-mute is not a responsible person, and, like
a minor and an imbecile, he cannot acquire
property, but ‘for practical reasons’ the Rabbis
laid it down that to deprive them of anything they
possess is robbery.’’
The Catholic Church continued this attitude,
which had been amplified by the writing of Saint
Augustine, quoting the Apostle Paul [7]:
‘‘... born ... deaf, which defect, indeed, hinders
faith itself, by the witness of the Apostle, who says,
‘Faith comes by hearing’...’’
The outcome of these concepts was that these deaf
non-verbal people were considered unable to learn
or achieve salvation.
The utilization and promulgation of vision as a
basis and curriculum for deaf communication begins
in the Benedictine Monastery of San Salvador at
On
˜
a in Burgos, Spain. The 16th century Benedic-
tine, Pedro Ponce de Leo`n, undertook the education
of two brothers, Francisco and Pedro de Velasco, the
children of the lord of On
˜
a and the nephew of the
constable of Castile. Typical of the time, their
parents, Juan de Velasco and Juana Enriquez de
Rivera, were consanguineous so as to preserve
wealth. They had nine children, four of whom
were deaf. The two deaf sisters, Juliana and Bernar-
dina, entered a convent. The brothers probably
entered the monastery of San Salvador at On
˜
ain
1547
/48.
De Leo`n, the Benedictine, would have had knowl-
edge of 
/360 different signs used for communica-
tion during periods of silence [9]. These signs were
used to describe the activities of daily life, such as
‘‘... eating utensils, objects used in the mass, gar-
ments, food, and tools’’, as well as ‘‘... emotional
states, dignitaries of the monastery ...’’ [7]. It has
been suggested [7] that de Leo` n also utilized the
indigenous semantic ‘‘home’’ signs [10] that these
brothers had acquired when living with their two
deaf sisters. A motivation for this may be found in
the will of their father, Juan de Velasco, in which he
Sign language 465

petitioned the Emperor and was granted the right to
allow his deaf sons to inherit his estates if his eldest
hearing son should predecease them. This unusual
provision would have been more sustainable if the
deaf sons could communicate. The method of
teaching involved use of the written word, a manual
alphabet and the use of both the Benedictine signs
and those indigenous signs that the children had
developed. The education was successful, as attested
by the ability of both boys to speak and to read and
write in Spanish, Greek and Latin.
De Leo`n educated other deaf children of the
Spanish nobility, including at least one of the sisters
of Francisco and Pedro, and recorded his method in
a manuscript entitled Doctrina para los mudos sordo.
This was known to exist up to 1821, after which it
and its copies were lost or destroyed, although there
may be one page remaining [11].
Systematic application and diffusion of sign
language as an aid in the teaching of the deaf:
17th century
During the years after the death of de Leo` n, deaf
education, limited to the aristocracy, migrated from
the monastery to the home. Amongst these teachers
of the deaf was Manuel Ramı´rez de Carrio´n, the
tutor of the congenitally deaf Alonso Ferna´ndez de
Co´rdoba y Figueroa, who achieved a high level of
success. Carrio´n, in 1615, was called to Madrid to
teach the son of the deceased sixth Captain of
Castile, Luis Ferna´ndez de Velasco, the grand
nephew of de Leo`n’s two original pupils, Francisco
and Pedro. Luis’s mother, Juana de Co´ rdoba,
Duchess of Frias, needed to have her son educated
to take communion so that he could be a ‘‘legal’’
person and thus she could be regent until he came of
age. Thus great resource was invested in enabling
him to communicate. Carrio´n’s educational techni-
ques included the use of finger spelling. He re-
mained Luis’s tutor for 4 years until he was called
back to Alonso Ferna´ndez.
The new tutor was Jan Pablo Bonet (1579
/1633),
born near Zaragoza, who began his career as a
mercenary and entered the service of de Velasco as
a translator. He acquired his knowledge of deaf
instruction by rooming with and observing the
secretive Carrio´n. In 1620 he published the first
book concerning the education of the deaf Reduction
de las letras y arte para ensen
˜
ar a ablar los mudos [12].
Bonet did not continue as a teacher but went on to
become a state official. His book was of great
importance as it was the first to widely disseminate
the techniques of teaching the deaf by means of
finger spelling, while deprecating the use of signs [7]:
‘‘In any home where there are mutes ... it is not
well that those who talk to him use signs, nor that
they permit him to make use of them.’’
There was, however, mention of the use of somewhat
arbitrary signs, those for which the meaning is
derived from agreement and not by resemblance to
the word. One such use of this form of ‘‘genuine’’
sign was to explain verb tense [7]:
‘‘For ‘past’ the hand moved back over the
shoulder, and for ‘future’ the hand arched forward
in front of the body.’’
Sir Kenelm Digby, the English ambassador to
Spain, met the 13-year-old Luis and was amazed by
the talent of this young person who could read and
write not only in Spanish but also in Latin, Greek
and other languages. Twenty years later, in 1644,
Digby described Luis in his book entitled Tw o
Treatises: In one of which, the Nature of Bodies in the
other, the Nature of Mans Soule, is looked into: In a way
of discovery of the Immortality of Reasonable Soules as
an extraordinary deaf person who was highly edu-
cated, adept at lip reading and in all ways capable.
Digby’s book, which was reprinted, translated into
German and widely disseminated, did much to inform
the world of the possibility of educating the deaf.
The codification of sign language syntax,
formation of a curriculum and open access:
18th and 19th centuries
The recognition of sign language as a complete
language and the design and implementation of a
curriculum to teach this language begins with
Charles Michel de L’E
´
pe´e. L’E
´
pe´e, a Jansenist, was
banned from preaching but found his vocation by
chance when he met two deaf girls who were being
taught through pictures. He felt that faith and
salvation should not be dependent on hearing and
could be achieved through signs. Using his father’s
house and his own funds, L’E
´
pe´e established, in
1771, the first free school for the deaf. His first
publication appeared in 1774 [13]. He established
and published syntax for sign language.
The successor to L’E
´
pe´e, in 1790, was the priest
Roch-Ambroise Sicard, who had come to Paris
to learn from L’E
´
pe´e and then established a
school for the deaf in Bordeaux. The Parisian
school for the deaf and de L’E
´
pe´e, major humane
triumphs for France, were highly regarded by
an aristocracy, soon to be eclipsed, who were empa-
thetic with the education of these unfortunates. The
National Assembly passed a law establishing the
school for the deaf on 29 July, 1791 [14]. This was
466 R. J. Ruben

dedicated to L’E
´
pe´e and was sanctioned by Louis
XVI, at that time a constitutional monarch and a
virtual prisoner in the Tuilleries, a month following his
arrest at Varennes. This was the first state-sponsored
school for the deaf and was open to all. It was one of
the last acts of Louis XVI, soon to be called ‘‘King of
the French’’, and then simply ‘‘Louis Capet’’.
Sicard continued the work of de L’E
´
pe´e during the
early years of the French Revolution. Although
politically conservative, Sicard was able to persuade
the National Assembly that aid for the handicapped
was part of the ‘‘natural duties’’ encompassed by the
‘‘rights of man’’. This was the foundation for our
system of the care and education of all children, the
basis for the concept of ‘‘The least restrictive
educational pathway’’ [15].
Controversy: 19th to 20th centuries
During the 19th century, additional educational
systems developed based philosophically on the
premise that the deaf need to communicate orally
and that the use of sign language would interfere
with the development of oral language; sign language
was the path of least resistance and the deaf child
would not be motivated to learn to speak. Until the
1880s both educational systems, sign and oralism,
coexisted. At the International Congress of Teachers
of the Deaf held in Milan in 1880, dominated by
oralists, a number of resolutions were passed. The
ones with the most far-reaching consequence are as
follows [17]:
‘‘I. The Congress, considering the incontestable
superiority of speech over signs in restoring the
deaf-mute to society, and giving him a more
perfect knowledge, declares that the oral method
ought to be preferred to that of signs for the
education and instruction of the deaf and dumb.
II. The Congress, considering that the simulta-
neous use of speech and signs has the disadvantage
of injuring speech, lip reading and the precision of
ideas, declares that the Pure Oral Method ought to
be preferred.’’
Controversy and acrimony characterized the
means of linguistic communication and the educa-
tion of the deaf for most of the 20th century.
Studies [16] have shown that outcomes of the totally
oral educational process have been poor. Towards
the middle of the 20th century there was a
movement towards the incorporation of signs in
combination with oral language, known as total
communication. Today there is the possibility that
early use of the cochlear implant may allow auditory-
based language in many deaf children.
Conclusions
Vision alone is able to establish language. There are
now tools, functional MRI, PET scans and the
recording of evoked potentials, which allow the
exploration of the physiological bases of language. It
is no surprise that these techniques reflect the obser-
vations of Socrates (‘‘of the deaf and dumb who have
words without sound ...’’) that the experiments of
nature, the use of vision, for language acquisition have
aided in the understanding of the biological bases of
language. Language is an intrinsic property of the
nervous system which is dependent on a sensory
input, but not on any particular sensory input.
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