My friend Paul and I point out to each other certain details of the landscape; and Paul's finger, which is pointing out the church tower, is not a finger for me that I think of as orientated towards a church tower for me, it is Paul's finger which itself shows me the tower that Paul sees, just as, conversely, when I make a movement towards some point in the landscape that I can see, I do not imagine that I am producing in Paul, in virtue of some pre established harmony, inner visions merely analogous to mine: I believe, on the contrary, that my gestures invade Paul's world and guide his gaze.