“[The universe is] haphazard, morally neutral, and unimaginably violent.”

Spark (2014)

Henry Powell Spring in 1944; popularized by John F. Kennedy misquoting Dante (24 June 1963) http://www.bartleby.com/73/1211.html. Dante placed those who "non furon ribelli né fur fedeli" [were neither for nor against God] in a special region near the mouth of Hell; the lowest part of Hell, a lake of ice, was for traitors.
According to the John F. Kennedy Presidential Library & Museum http://www.jfklibrary.org/Research/Research-Aids/Ready-Reference/JFK-Quotations.aspx President Kennedy got his facts wrong. Dante never made this statement. The closest to what President Kennedy meant is in the Inferno where the souls in the ante-room of hell, who "lived without disgrace and without praise," and the coward angels, who did not rebel but did not resist the cohorts of Lucifer, are condemned to continually chase a banner that is forever changing course while being stung by wasps and horseflies.
See Canticle I (Inferno), Canto 3, vv 35-42 for the notion of neutrality and where JFK might have paraphrased from.
Misattributed

At the signing of a charter establishing the German Peace Corps, Bonn, West Germany (24 June 1963);


Source: http://www.jfklibrary.org/Research/Research-Aids/Ready-Reference/JFK-Quotations.aspx According to the John F. Kennedy Presidential Library & Museum] President Kennedy got his facts wrong. Dante never made this statement. The closest to what President Kennedy meant is in the Inferno where the souls in the ante-room of hell, who "lived without disgrace and without praise," and the coward angels, who did not rebel but did not resist the cohorts of Lucifer, are condemned to being whirled through the air by great winds while being stung by wasps and horseflies. Dante placed those who "non furon ribelli né fur fedeli" — were neither for nor against God, in a special region near the mouth of Hell; the lowest part of Hell, a lake of ice, was for traitors.
Source: https://web.archive.org/web/20201213100425/https://www.jfklibrary.org/learn/about-jfk/life-of-john-f-kennedy/fast-facts-john-f-kennedy/john-f-kennedys-favorite-quotations-dantes-inferno According to the John F. Kennedy Presidential Library & Museum in the undated article "John F. Kennedy's Favorite Quotations: Dante's Inferno"
President Kennedy's quote was based upon an interpretation of Dante's Inferno. As Robert Kennedy explained in 1964, "President Kennedy's favorite quote was really from Dante, 'The hottest places in Hell are reserved for those who in time of moral crisis preserve their neutrality.'" This supposed quotation is not actually in Dante's work, but is based upon a similar one. In the Inferno, Dante and his guide Virgil, on their way to Hell, pass by a group of dead souls outside the entrance to Hell. These individuals, when alive, remained neutral at a time of great moral decision. Virgil explains to Dante that these souls cannot enter either Heaven or Hell because they did not choose one side or another. They are therefore worse than the greatest sinners in Hell because they are repugnant to both God and Satan alike, and have been left to mourn their fate as insignificant beings neither hailed nor cursed in life or death, endlessly travailing below Heaven but outside of Hell. This scene occurs in the third canto of the Inferno.
Source: http://www.bartleby.com/73/1211.html According to Bartleby.com
Kennedy's remark may have been inspired by the passage from Dante Alighieri’s La Comedia Divina “Inferno,” canto 3, lines 35–42 (1972) passage as translated by Geoffrey L. Bickersteth: "by those disbodied wretches who were loth when living, to be either blamed or praised. [...] Fear to lose beauty caused the heavens to expel these caitiffs; nor, lest to the damned they theng ave cause to boast, receives them the deep hell." A more modern-sounding translation from the foregoing Dante’s Inferno passage was translataed 1971 by Mark Musa thus: “They are mixed with that repulsive choir of angels … undecided in neutrality. Heaven, to keep its beauty, cast them out, but even Hell itself would not receive them for fear the wicked there might glory over them.”

King quoted here John F. Kennedy who at the signing of a charter establishing the German Peace Corps in Bonn, West Germany (24 June 1963) remarked: Dante once said that the hottest places in hell are reserved for those who, in a period of moral crisis, maintain their neutrality.
According to Bartleby.com, Kennedy's remark may have been inspired by the passage from Dante Alighieri’s La Comedia Divina “Inferno,” canto 3, lines 35–42 (1972) passage as translated by Geoffrey L. Bickersteth: "by those disbodied wretches who were loth when living, to be either blamed or praised. [...] Fear to lose beauty caused the heavens to expel these caitiffs; nor, lest to the damned they theng ave cause to boast, receives them the deep hell." A more modern-sounding translation from the foregoing Dante’s Inferno passage was translataed 1971 by Mark Musa thus: “They are mixed with that repulsive choir of angels … undecided in neutrality. Heaven, to keep its beauty, cast them out, but even Hell itself would not receive them for fear the wicked there might glory over them.”
This is also often quoted slightly differently as: "The hottest place in Hell is reserved for those who remain neutral in times of great moral conflict"
1960s, Why I Am Opposed to the War in Vietnam (1967)
Context: I see this war as an unjust, evil, and futile war. I preach to you today on the war in Vietnam because my conscience leaves me with no other choice. The time has come for America to hear the truth about this tragic war. In international conflicts, the truth is hard to come by because most nations are deceived about themselves. Rationalizations and the incessant search for scapegoats are the psychological cataracts that blind us to our sins. But the day has passed for superficial patriotism. He who lives with untruth lives in spiritual slavery. Freedom is still the bonus we receive for knowing the truth. "Ye shall know the truth," says Jesus, "and the truth shall set you free." Now, I've chosen to preach about the war in Vietnam because I agree with Dante, that the hottest places in hell are reserved for those who in a period of moral crisis maintain their neutrality. There comes a time when silence becomes betrayal.

Salon interview (2001)

"A Coincidence," http://books.google.com/books?id=vmpHAAAAIAAJ&q=%22Although+we+talk+so+much+about+coincidence+we+do+not+really+believe+in+it+in+our+heart+of+hearts+we+think+better+of+the+universe+we+are+secretly+convinced+that+it+is+not+such+a+slipshod+haphazard+affair+that+everything+in+it+has+meaning%22&pg=PA215#v=onepage Going Up Stories and Sketches (1950)

Source: Academy Series - Priscilla "Hutch" Hutchins, Deepsix (2001), Chapter 11 (p. 180)

A Propos of Lady Chatterley's Lover (1929)
Context: Sex is the balance of male and female in the universe, the attraction, the repulsion, the transit of neutrality, the new attraction, the new repulsion, always different, always new. The long neuter spell of Lent, when the blood is low, and the delight of the Easter kiss, the sexual revel of spring, the passion of midsummer, the slow recoil, revolt, and grief of autumn, greyness again, then the sharp stimulus of winter of the long nights. Sex goes through the rhythm of the year, in man and woman, ceaselessly changing: the rhythm of the sun in his relation to the earth. Oh, what a catastrophe for man when he cut himself off from the rhythm of the year, from his unison with the sun and the earth. Oh, what a catastrophe, what a maiming of love when it was a personal, merely personal feeling, taken away from the rising and the setting of the sun, and cut off from the magic connection of the solstice and the equinox! This is what is the matter with us. We are bleeding at the roots, because we are cut off from the earth and sun and stars, and love is a grinning mockery, because, poor blossom, we plucked it from its stem on the tree of Life, and expected it to keep on blooming in our civilised vase on the table.