linguistic:translation, structural:scholar_edition
Pay it forward

On that theme, the phrase " pay it forward ", though it was already in occasional use as a quotation, was popularized by Robert A. Heinlein in his book Between Planets, published in 1951:

The banker reached into the folds of his gown, pulled out a single credit note. "But eat first—a full belly steadies the judgment. Do me the honor of accepting this as our welcome to the newcomer."

His pride said no; his stomach said YES! Don took it and said, "Uh, thanks! That's awfully kind of you. I'll pay it back, first chance."

"Instead, pay it forward to some other brother who needs it."

He referred to this in a number of other stories, although sometimes just saying to pay a debt back by helping others, as in one of his last works, Job, a Comedy of Justice.

Heinlein was a mentor to Ray Bradbury, giving him help and quite possibly passing on the concept, made famous by the publication of a letter from him to Heinlein thanking him. In Bradbury's novel Dandelion Wine, published in 1957, when the main character Douglas Spaulding is reflecting on his life being saved by Mr. Jonas, the Junkman:

How do I thank Mr. Jonas, he wondered, for what he's done? How do I thank him, how pay him back? No way, no way at all. You just can't pay. What then? What? Pass it on somehow, he thought, pass it on to someone else. Keep the chain moving. Look around, find someone, and pass it on. That was the only way…

Bradbury has also advised that writers he has helped thank him by helping other writers.

Heinlein both preached and practiced this philosophy; now the Heinlein Society, a humanitarian organization founded in his name, does so, attributing the philosophy to its various efforts, including Heinlein for Heroes, the Heinlein Society Scholarship Program, and Heinlein Society blood drives. Author Spider Robinson made repeated reference to the doctrine, attributing it to his spiritual mentor Heinlein.