Tip of the iceberg

From The Point: "For much of modern history, icebergs have helped us speak about deeper reservoirs of meaning. The phrase 'just the tip of the iceberg' has, at least since the environmental movements of the 1960s, expressed the idea that there is much more to something than meets the eye. As the historian William Cronon observes, internalizing nature through language like this is our best way of understanding it — and ourselves. 'The nature inside our heads is as important to understand as the nature that surrounds us,' he writes, 'for the one is constantly shaping and filtering the way we perceive the other.'"