“Here are two kinds of light, the light on the hither side of the darkness and the light beyond the darkness. We must press on through the darkness and the terror of it if we would reach the holier light beyond.
We are here — no matter who put us here, or how we came here — to fulfil a task. We cannot afford to go of our own volition until the last item of our duty is discharged.”

Interviewed by Eric Nordern, Playboy (September 1968); later published in Stanley Kubrick: Interviews (2001) http://books.google.com/books?id=iOU9bIlnPHIC&pg=PA73&lpg=PA73&dq=however+vast+darkness+supply+light&source=web&ots=WSx0cc_E1n&sig=OMT0-SOVCFtSN8a1WosgIR1PMWA
Context: The most terrifying fact about the universe is not that it is hostile but that it is indifferent; but if we can come to terms with this indifference and accept the challenges of life within the boundaries of death — however mutable man may be able to make them — our existence as a species can have genuine meaning and fulfillment. However vast the darkness, we must supply our own light.

Source: The Library at Night

Source: Change of Heart

Source: Meditations in Wall Street (1940), p. 80

1960, The New Frontier
Context: But I think the American people expect more from us than cries of indignation and attack. The times are too grave, the challenge too urgent, and the stakes too high — to permit the customary passions of political debate. We are not here to curse the darkness, but to light the candle that can guide us through that darkness to a safe and sane future. As Winston Churchill said on taking office some twenty years ago: if we open a quarrel between the present and the past, we shall be in danger of losing the future. Today our concern must be with that future. For the world is changing. The old era is ending. The old ways will not do. [... ] It is a time, in short, for a new generation of leadership — new men to cope with new problems and new opportunities.

Section 3.13 <!-- p. 183 -->
The Crosswicks Journal, A Circle of Quiet (1972)
Context: St. John said, "And the light shineth in the darkness; and the darkness comprehended it not." The light shines in the darkness and the darkness does not understand it, and cannot extinguish it ( I need the double meaning here of comprehend). This is the great cry of affirmation that is heard over and over again in our imaginative literature, in all art. It is a light to lighten our darkness, to guide us, and we do not need to know, in the realm of provable fact, exactly where it is going to take us.

Source: Unwind