Margaret Atwood, Negotiating with the Dead -- “Obstruction, obscurity, emptiness, disorientation, twilight, blackout, often combined with a struggle or path or journey – an inability to see one's way forward, but a feeling that there was a way forward, and that the act of going forward would eventually bring about the conditions for vision – these were the common elements in many descriptions of the process of writing.”
Images of passing from darkness into light are common in fiction. In Barry Unsworth's Sacred Hunger, Deakin's childhood escape from the shed where his father locked him up is the last thing he thinks of before dying in Africa -- “That light, that enlargement had been destination enough. He had never found it again, he had run ever since between narrowing walls, under lowering skies.” Unsworth uses a similar image for Paris's emergence from the slave-ship's festering hold onto its deck, immediately before instigating a mutiny -- “In all the years of his life remaining, Paris was to carry the impression of that emergence into light and space.”
Joseph Conrad wrote in “Henry James, an Appreciation” -- “Action in its essence, the creative art of a writer of fiction may be compared to rescue work carried out in darkness against cross gusts of wind swaying the action of a great multitude. It is rescue work, this snatching of vanishing phrases of turbulence, disguised in fair words, out of the native obscurity into a light where the struggling forms may be seen, seized upon, endowed with the only possible form of permanence in this world of relative values – the permanence of memory. And the multitude feels it obscurely too; since the demand of the individual to the artist is, in effect, the cry, 'take me out of myself!' meaning really, out of my perishable activity into the light of imperishable consciousness.”
Anna Quindlen, How Reading Changed my Life – “It is like the rubbing of two sticks together to make a fire, the act of reading, an improbable pedestrian task that leads to heat and light. Perhaps this only becomes clear when one watches a child do it.”
E.O. Wilson would of course link these metaphors to the fact that we are a diurnal species, many of whose ancestral predators were nocturnal.