Discourse and gibbons, etc.

[Harold F. Schiffman]

I'm still wondering about what is discourse and what is not. The fact that
possums, gibbons or birds or whatever can be deceptive, using behaviors to
deceive other animals, makes me think about the following:

A friend of my mother recently had her car "carjacked."  She had entered
the vehicle and was about to drive away from a parking lot shopping center
when a man tapped on the window and pointed down at the ground.  She
opened the window to ask what was the matter; he continued to point down.
She opened the door to see what he was pointing at, whereupon he pulled
the door open further, dragged her out of the car, got in, and drove off
with the car.

The man did not speak a word; he used deceptive gestures to get her
attention, and got what he wanted.  Is this "discourse"?

Hal Schiffman