The gaze of dogs who don’t understand and who don’t know that they might be right not to understand. —Italo Calvino A few days ago, while I was out strolling harmlessly near home, a savagely snarling cattle-dog sprang at my hand. His mistress had him on a short, stout lead, and no harm was done. She was embarrassed: “I’m so sorry! He’s such a good dog at home. He just does this occasionally when we’re out.” Apart from startling me momentarily, the encounter had not upset me in the slightest, but it called up an astonishingly sharp and swift recollection…