“There will be a small office party next Tuesday,” Mr. Storch announced to his workers. “We’re celebrating the five-year anniversary of Storch Studios.”

“Congratulations!” they chorused.

“I heard that you play beautifully on the keyboard,” Mr. Storch said to Jay Farber, a freelance worker there. “It would be nice to have some music.”

“I have another job that day,” replied Jay, “but I’d be happy to lend my keyboard to you if someone else can play.”

“Actually, I can play,” Mr. Storch said. “Please bring it with you when you come to work on Monday, so it will be available for the party.”

On Monday, Jay Farber brought his keyboard and gave it to Mr. Storch. “Here it is,” he said. “Please take care of it.”

“Thank you very much,” said Mr. Storch. “I’ll put it away in the cabinet till tomorrow.”

The next morning, when Mr. Storch opened the cabinet to set up the keyboard, he saw that it was not there.

“This is really bad,” said Mr. Storch. “I guess we’ll have to use music CDs for the party.”

When Jay Farber came to work the following day, Mr. Storch told him, “I’m awfully sorry about your keyboard. I put it in this cabinet, but it wasn’t there when I came in yesterday morning.”

“You’re kidding me!” said Jay. “I’ve been playing on this keyboard for the past three years, and I love its feel! It costs $500 to get a new one.”

“It’s three years old, though,” Mr. Storch pointed out. “Its value as a used item is only half that.”

“That doesn’t help me,” said Jay. “I need to buy a new one to continue playing.”

“You can buy one second-hand,” suggested Mr. Storch. “Besides, I know I locked the cabinet. It’s really strange that it got stolen.”

While they were debating the issue, another worker piped up: “This sounds like a question from the Business Weekly. Go ask Rabbi Dayan!”

Mr. Storch and Jay said, “Great idea!”

They asked Rabbi Dayan if they could meet with him.

“Is Mr. Storch responsible for the keyboard?” Jay asked. “How much does he have to pay?”

“A person who borrows an item is responsible for it, even if it’s damaged or lost through circumstances beyond his control, and certainly for theft (C.M. 340:1),” said Rabbi Dayan. “However, when borrowing or damaging a used item, it is not necessary to replace it with a new one. The loss or damage is evaluated at the item’s current worth, taking into consideration its depreciation.”

“So he owes me $250, then,” said Jay Farber.

“Actually, in this particular case,” continued Rabbi Dayan, “Mr. Storch is not legally responsible for the borrowed item, based on the principle of b’alav imo (the owner is with him).”

“What’s that?” asked Jay.

“The Torah states regarding one who borrows: ‘If the owner is with him,’ the borrower is not responsible,” explained Rabbi Dayan. “The Gemara (B.M. 94a) interprets this to mean that if the owner of the item is in the employ or service of the borrower, the borrower is not responsible for the item.”

“Why is that?” asked Mr. Storch.

“One of the rationales offered for this law,” answered Rabbi Dayan, “is that when the owner of the item is in the service of the borrower, there is an expectation that the owner will continue to keep an eye on it. Therefore, the Torah granted an exemption (Sefer Hachinuch #60).”

“But I wasn’t working that day,” asked Jay Farber.

“The owner must be in the service of the borrower at the time that he borrowed the item,” replied Rabbi Dayan, “since that is the point at which the borrower assumes responsibility for it. Even if the owner is no longer in his employ at the time that the item is lost, the borrower remains exempt (C.M. 346:1).”

“What if the item was lost through negligence, such as if I hadn’t locked the door?” asked Mr. Storch.

“There is a dispute about this in the Gemara (95a),” answered Rabbi Dayan. “Most authorities rule that it is not possible to make the borrower pay, and he remains exempt. However, if the borrower actively damaged the item, he is responsible for it as any other person who damages (see 301:1; Pischei Teshuva 176:13).”

“This is the halacha,” concluded Rabbi Dayan. “However, Mr. Storch should take into consideration interpersonal decency and gratitude.”