Our disenchantment of the night through artificial lighting may appear, if it is noticed at all, as a regrettable but eventually trivial side effect of contemporary life. That winter hour, though, up on the summit ridge with the stars falling plainly far above, it seemed to me that our estrangement from the dark was a great and serious loss. We are, as a species, finding it increasingly hard to imagine that we are part of something which is larger than our own capacity. We have come to accept a heresy of aloofness, a humanist belief in human difference, and we suppress wherever possible the checks and balances on us – the reminders that the world is greater than us or that we are contained within it.

To understand light you need first to have been buried in the deep-down dark.