“Men born in hot countries love the night because it refreshes them and have a horror of light because it burns them; and therefore they are of the colour of night, that is black. And in cold countries it is just the contrary.”

The Desolate City, from Collected Poems (1914)

"Black Flag" in Collected Poems (1983)
Context: For out of black
soul's night have stirred
dawn's cold gleam,
morning's singing bird. Let black day die,
let black flag fall,
let raven call,
let new day dawn
of black reborn.

Light (1919), Ch. XVI - De Profundis Clamavi
Context: Men have gone towards each other because of that ray of light which each of them contains; and light resembles light. It reveals that the isolated man, too free in the open expanses, is doomed to adversity as if he were a captive, in spite of appearances; and that men must come together that they may be stronger, that they may be more peaceful, and even that they may be able to live.
For men are made to live their life in its depth, and also in all its length. Stronger than the elements and keener than all terrors are the hunger to last long, the passion to possess one's days to the very end and to make the best of them. It is not only a right; it is a virtue.

Neo-Conned! Just War Principles: A Condemnation of War in Iraq (eds. Liam O'Huallachain and J. Forrest Sharpe, 2005)
2000s

Source: Shakespeare's Sonnets

Edna St. Vincent Millay, in "First Fig" from A Few Figs from Thistles (1920); said to be a motto Roald Dahl lived by.
Misattributed
Variant: My candle burns at both ends;
It will not last the night;
But, ah, my foes, and, oh, my friends —
It gives a lovely light.
Source: Boy: Tales of Childhood

Misattributed
Source: Edna St. Vincent Millay, in "First Fig" from A Few Figs from Thistles (1920); said to be a motto Roald Dahl lived by.

CI.
Caelica (1633)

C'est ici le combat du jour et de la nuit... Je vois de la lumière noire.
Last words (1885-05-22); quoted in Olympio, ou la vie de Victor Hugo by André Maurois (1954)