India, March 18 -- The two bougainvillaea trees are currently in bloom, synchronising in perfect jugalbandi with each other, twinning brightly, here at Lodhi Garden. The pink flowers are drifting down continually on the ground. The pair is iconic; every Delhiwale should see it. The city itself, it seems, produces pairs in countless forms. Once you perceive the pattern, you spot it across the megapolis.

Take Kasturba Gandhi Marg, where the British Council stands across the road from the American Center (both institutions are popular for their libraries, though the latter's has severely contracted over the years). In central Delhi, statues of Russian writers stand a short walk apart: Pushkin near Mandi House, Tolstoy on Janpath. Coffee pla...