“I am I because my little dog knows me.” The words are Gertrude Stein’s; the dog in this picture knew my parents and lived with them before I was born, and they celebrated its existence in a pair of studio portraits. The other shows the dog looking straight at the lens with its paws on the back of a bentwood chair. I prefer the more formal one, with the lady’s wrist watch raffishly slung around the dog’s neck.

Last summer, during a visit to Vancouver, my nine-year-old son climbed the pediment of a cast-iron traffic-light standard and put his palm on the glowing hand that warns pedestrians to stay put. My mother pointed out afterwards that my photograph of the event contained its own French caption, in the word visible over his shoulder: main.