27 July 1814

Logic

5

Ch.3.III. Operations

'.7.VI. Communication

21

5

The touch has been mentioned above as one of the three senses through the medium of which the operations of discourse are capable of being performed. This accordingly is a medium through which in the case of the blind, {by the help of modern ingenuity} it is customarily carried on, in many well-known instances. But where one of the three conversible senses is in this way employed, it is never any otherwise than in a remote way, viz. through the intervention of one of the other two conversible ones if such they may be called. (a)

In the case even of a blind person, this medium may be composed not only of the ordinary audible, but of the ordinary visible signs, if so it be that he was once in possession of the sense of sight, and in that time obtained an acquaintance with the use and import of the ordinary visible characters.

Of late years, the faculty of discourse has even been communicated to persons who from their birth were deaf, and from that cause or any other at the same time dumb: but in all these cases he has been in possession of the sense of seeing, and thereby has been rendered susceptible of discourse and converse by means of visible characters.

Should a human being ever be found, unfortunate enough to have been from its birth destitute of the sense of sight, as well as of that of hearing, to communicate to him the faculty of converse or discourse in any degree or to any purpose will, it seems evident, be necessarily found altogether impractical.

In the same deplorable case will any person be, who being born dumb or deaf, shall have lost his sight without having as yet received in any competent degree that sort of intellectual instruction and literary instruction of which persons labouring under that complicated imperfection are susceptible.

(a)  Exemplify: viz.

1. Finger language.

2. Tangible diagrams.

3. Tangibly marked cards.

4. Tangible musical-notes.