The Fleeting Pleasures of Sin

I've been reading The Great Divorce. It's a very interesting allegory written by C.S. Lewis. In it we meet Ghosts and Solid People. The Ghosts take a bus ride up to heaven and take a look around. Most of them end up prefering where they came from and want to leave. However, the Solid People try and help the Ghosts understand that this place is what they were made for. Here's one of the Solid People, George MacDonald, explaining how sin works.

"The sensualist...begins by pursuing a real pleasure, though a small one. His sin is the less. But the time comes on when, though the pleasure becomes less and less and the craving fiercer and fiercer, and though he knows that joy can never come that way, yet he prefers to joy the mere fondling of unappeasable lust and would not have it taken from him. He'd fight to the death to keep it. He'd like well to be able to scratch; but even when he can scratch no more he'd rather itch than not."