“Love is an abstract noun, something nebulous. And yet love turns out to be the only part of us that is solid, as the world turns upside down and the screen goes black.”

"Come, Holy Harlequin" (1974)
Context: Teach the crippled how to leap,
Throw their crutches on a heap,
Rock, love, carry it away, turn it upside down.
Rock, love, carry it away,
Lift the world up by your levity,
Rock, love, carry it away, turn it upside down.

Source: Colorless Tsukuru Tazaki and His Years of Pilgrimage

Attributed to Lee in "Harpy Hall of Fame: Mother Ann Lee (1736-1784)" at The Pursuit of Harpyness (4 February 2009) http://www.harpyness.com/2009/02/04/harpy-hall-of-fame-mother-ann-lee-1736-1784/; no earlier attributions have as yet been located.
Disputed

Source: The Space Merchants (1953), Chapter 8 (p. 105)

Part 1.3 Rights of Man
1790s, Rights of Man, Part I (1791)

Whoops! It's Christmas (1959)
Context: The central core of truth is that Christmas turns everything upside down, the upside of heaven come down to earth. The Christmas story puts a new value on every man. He is not a thing to be used, not a chemical accident, not an educated ape. Every man is a V. I. P., because he has divine worth. That was revealed when "Love came down at Christmas." A scientist said, making a plea for exchange scholarships between nations, "The best way to send an idea is to wrap it up in a person." That was what happened at Christmas. The idea of divine love was wrapped up in a person.