Short story where a man makes a deal with the devil for immortality

Question

Can’t remember what book this mid 20th century short story was in - I should still have it on my shelves somewhere!

A guy makes a deal with the devil: his soul in exchange for immortality. “Under the circumstances,” says the devil, “I don’t see how I can collect”. It is agreed that immortality does not extend to suicide.

The devil makes the necessary adjustments, but in the process, removes the guy’s conscience.

The guy has a fine time of it, at least for a while. Eventually however, he becomes bored and dissatisfied.

When he summons the devil back to fix the nagging sensation that something is missing, the devil warns him that he won’t like the fix, but he nevertheless insists that the devil return what he took.

Of course, the guy is completely overwhelmed with remorse once his conscience is back and he is confronted with all the terrible things he’s done.

“He raised the gun to his head, and the devil came in”

Answer 1

By These Presents by Henry Kuttner.

The protagonist is Fenwick, and the story ends when the Devil returns Fenwick's superego:

Then why," Fenwick demanded, "am I unable to enjoy my immortality? What is it that stops me at the threshold of everything I attempt? I'm tired of living like a god if I have to stop with immortality only, and no real pleasure in it."

"Hold still," the devil said. "There. My dear Fenwick, you are not a god. You're a very limited mortal man. Your own limitations are all that stand in your way. In a million years you could never become a great musician or a great economist or any of the greats you dream of. It simply isn't in you. Immortality has nothing to do with it. Oddly enough——" And here the devil sighed. "Oddly enough, those who make bargains with me never do have the capability to use their gifts. I suppose only inferior minds expect to get something for nothing. Yours is distinctly inferior."

The cool breeze ceased.

"There you are," the devil said. "I have now returned what I took. It was, in Freudian terms, simply your superego."

And it ends:

A terrible, smashing awareness struck down upon Fenwick like the hand of a punishing God. He knew now what he had done. He remembered his crimes. All of them. Every last terrible, unforgivable, immutable sin he had committed in the past twenty years.

His knees buckled under him. The world turned dark and roared in his ears. Guilt was a burden he could hardly stagger under. The images of the things he had seen and done in the years of his carefree evil were thunder and lightning that shook the brain in his skull. Intolerable anguish roared through his mind and he struck his hands to his eyes to blot out vision, but he could not blot out memory.

Staggering, he turned and stumbled toward his bedroom door. He tore it open, reeled across the room and reached into a bureau drawer. He took out a revolver.

He lifted the revolver, and the devil came in.