I was asking you: where are we when we draw? The question seems to be expecting a spatial answer, but mightn’t it be a temporal one? Isn’t the act of drawing, as well as the drawing itself, about becoming rather than being? Isn’t a drawing the polar opposite of a photo? The latter stops time, arrests it; whereas a drawing flows with it. Could we think of drawings as eddies on the surface of the stream of time? from a dialogue between John Berger and his son Yves.
— Seeing Through Drawing, a celebration of John Berger, July 2017
For the artist drawing is discovery. And that is not just a slick phrase, it is quite literally true. It is the actual act of drawing that forces the artist to look at the object in front of him, to dissect it in his mind’s eye and put it together again;

A line, an area of tone, is not really important because it records what you have seen, but because of what it will lead you on to see. Following up its logic in order to check its accuracy, you find confirmation or denial in the object itself or in your memory of it. Each confirmation or denial brings you closer to the object, until finally you are, as it were, inside it: the contours you have drawn no longer marking the edge of what you have seen but the edge of what you have become.
— John Berger: Drawing is discovery, August 195