“How does your father cure people? He gives them medicines they think they need. Then they get better. He hopes. I give people money they need. Then they get richer. They hope. I hope. Otherwise they can’t pay me back. It’s obvious.”

Jacob considered.

“So how do you decide whether they’re a good risk?”

“That is a good question.” Baruch seemed to soften a bit. “Maybe you’re not so stupid after all.” He paused. “You need security. The man has to pledge something for the loan, so you have to figure what it’s worth, and whether he really owns it. And you need a good head for numbers. If the risk is high, you’re going to need a higher interest rate to protect yourself. Are you understanding me?”

“I think so. You have to calculate.”

“Yes. But you know what. It’s not just that. It’s an art as well. You really have to understand the man’s affairs. And you have to judge his character. Sometimes that’s the most important thing of all. Character.” He shrugged. “So maybe it’s like being a physician. It’s instinct, you know. I’m a money physician. I look after people’s lives. It’s a terrible occupation.” He looked at Jacob to see how he was taking it.

“I think it’s interesting,” said Jacob frankly.

“It’s not so bad.”

“The Christians call it usury.”

“The Jews call it usury. It’s in the Torah. Thou shalt not lend money at interest. It says so.” He paused a moment. “You know something? The Torah is very good at telling you what not to do. But if there is no profit to be had, no interest, then there is no reason for anyone to lend, and so nobody can borrow anything. They can steal it from their grandmother, but they can’t borrow it.” He smiled. “But there is an escape clause. A Jew is not allowed to lend at interest to another Jew. But it doesn’t say that you can’t lend to someone who is not a Jew. So we can lend to Christians.”

“And the Christians are allowed to borrow from us.”

“By the same logic. They say they mustn’t lend at interest, because it says so in the Bible. But if a Jew is prepared to lend, then that’s all right. They say the Jew is probably going to hell anyway, so who cares? It’s one of the few occupations they allow us to follow, which is very convenient for them.” He made a dismissive motion with his hands. “They get the money. We go to hell.”

“But the Christians lend money too,” Jacob objected. “What about the Italian moneylenders, like the Lombards? I heard that they’re sanctioned by the pope himself.”

“Ah. But they don’t charge interest.”

“So how can they have any profit?”

“They charge a fee instead.”