"I see with eyes."
"But there is something beside seeing with eyes. There is a mind which ponders and selects."
"Too much of honour."
"No. No honour at all: a stated fact. Well now: think of negatives. They are dense in places: clear in places; and, in other places, more or less dense. Understand? Under the negative you put a certain paper; and expose it to light. Light goes through the clear places and stains the paper black: it partly goes through the more or less dense places; and stains the paper grey in various gradations of tint. It fails to go through the dense places and leaves the paper white. There is your photograph, a little black a little white and many different greys. Understand?"
"Yes, Santità."
"Your photograph is an image of the form, the contours, the modelling, the morbidezza, of the object before your lens. It lacks one thing. It has not colour. The process has tralated colour into monochrome. Do you see that?"
"Yes, Santità."
"Now white means a blend of all colours; and black means the absence of all colours. Then grey should mean some colours, of this quality or that, of this quantity or that, according to the clarity or the density of the grey. Understand?"
"Yes, Santità."