The author establishes that Norman Gortsby is accustomed to sitting on a bench in this park at dusk and watching the passing crowd. Gortsby must have heard many hard-luck stories on these evenings. He has become cynical. It would be hard for anyone to get any money out of him. He listens to the young man's story patiently, but he feels sure it is nothing but a scam, and he has no intention of parting with any money. Then when the young man is finished, Gortsby points out the one flaw in his story.
"Of course," said Gortsby slowly, "the weak point of your story is that you can't produce the soap."
The young man is completely flustered. All he can say is:
"I must have lost it."
But Gortsby shows the con-man he is wasting his time.
"To lose an hotel and a cake of soap on one afternoon suggests wilful carelessness," said Gortsby, but the young man scarcely waited to hear the end of the remark. He flitted away down the path, his head held high, with an air of somewhat jaded jauntiness.
This young man is obviously a novice. He has tailored a very good story but hadn't thought about being asked to show the cake of soap he supposedly went out to buy. His story was intended to make the "mark" or "prospect" believe that he was a country gentleman who didn't know a soul in London. Whoever would lend him enough money for one night's room rent might be making a friend of an aristocrat who would conceivably repay his generosity by inviting him to dinner, inviting down to his country manor for shooting, and introducing him to members of a higher social class. This was never said, but implied.
When Gortsby finds a cake of soap on the ground by the bench, he naturally thinks it belonged to the young man and that his whole story was true. Gortsby goes hurrying after him because he thinks he missed a chance to make an extremely valuable friend. He does not have to part with a sovereign. The young man only wanted a loan which he would return as soon as he could get a wire from his people in the country informing him of the name of the hotel he had sent them when it turned out he wasn't going to be staying at the Patagonian. Evidently it would take until the next day for the young man to receive the return telegram from the country.
Gortsby eagerly and apologetically gives the young con-man a sovereign plus the cake of soap.
"Here is my card with my address," continued Gortsby; "any day this week will do for returning the money, and here is the soap — don't lose it again it's been a good friend to you."
No doubt Gortsby has great expectations until he sees the elderly gentleman searching all around the bench they had previously been sharing. It turns out that the soap unmistakably belonged to the old man. Gortsby has not been made a fool by feeling sorry for the young man but by being conned into thinking that the young man was a country gentleman who didn't know a soul in London and might become a friend who could help him to rise in the world socially and financially. Gortsby wanted something for himself. The best way to manipulate people is to appeal to their selfish interest.
Would you persuade? Speak of interest, not of reason.
Benjamin Franklin, Poor Richard's Almanac