Autumn is the time of essences. To try to explain, let me revisit the quintessential autumnal poem, Keats’s “Ode to Autumn”. Some have said that this poem isn’t really about autumn at all. Keats wrote it during a period of beautiful, calm weather in Winchester, around September 19 1819: “How fine the air is,” he wrote to his friend Reynolds. “A temperate sharpness about it.” At times the poem seems to be more about late summer than about autumn: what are poppies doing in autumn? Shouldn’t the harvest be done?

Surely the poem is really about the process of ripening, the way autumn fills “all fruit with ripeness to the core”. The ode is an extended commentary on Edgar’s words to his father Gloucester in King Lear, “Ripeness is all”: like Shakespeare, Keats is talking not just about the ripening of fruit, but the maturing of human beings.