Sign languages are considered by linguists as full-fledged and grammatically very sophisticated languages. But they also have unique insights to offer on how meaning works in language in general.

Sign languages can help reveal hidden aspects of the logical structure of spoken language, but they also highlight its limitations because speech lacks the rich iconic resources that sign language uses on top of its sophisticated grammar.

For instance, the logical structure of the English sentence Sarkozy told Obama that he would be elected is conveyed more transparently in sign language. The English sentence is ambiguous, Schlenker explains, as he can refer to Sarkozy or to Obama. Linguists have postulated that this is because the sentence contains some unpronounced – but cognitively real – logical variables like x and y.

If the sentence is understood as Sarkozy (x) told Obama (y) that he (x) would be elected, with the same variable x on Sarkozy and on he, the pronoun refers to Sarkozy; if instead he carries the variable y, it refers to Obama. Remarkably, in sign language the variables x and y can be visibly realized by positions in space, e.g. by signing Sarkozy on the left and Obama on the right. (1)

See.

Now you know that it was about Sarkozy.

Listen.

Now you know what the other guy meant.

Feel.

Now you understand why the other one is even speaking to you.

Reach out with your senses.

It is all the same at the end.

Ideas may sometimes be conveyed better with images.

But blind people cannot see.

Ideas may sometimes be conveyed better with words.

But deaf people cannot hear.

At the end, you will need to reach out to understand what is said.

But not to the person talking to you.

But to the person inside you.

Listen carefully.

Do you listen anything?

See.

Listen.

Feel.

Why are you even listening?