Advice on two notes written by Albert Einstein describing his theory for happy living has been sold at an auction house in Jerusalem for $1.56 million.
The Nobel Prize-winning German-born physicist gave the notes to a Tokyo courier in 1922 instead of a tip.
He told the messenger that if he was lucky, the notes would become valuable.
Einstein devoted his life to science but suggested in the notes that achieving a long-dreamt-of goal did not necessarily guarantee happiness.
When the courier came to his room to make a delivery, the physicist did not have any money to reward him.
He had at the time just heard that he had won the Nobel Prize for physics and was in Japan on a lecture tour.
Instead, he handed the messenger a signed note - using stationery of the Imperial Hotel Tokyo - with one sentence, written in German: "A calm and humble life will bring more happiness than the pursuit of success and the constant restlessness that comes with it."
A second note written at the same time simply reads: "Where there's a will, there's a way." It sold for $240,000, Winner's auction house said on Tuesday.
The winning bids for both notes were far higher than the pre-auction estimated price, the auctioneers said.
It said the buyer of one of the notes was a European who wished to remain anonymous.
The seller is reported to be the nephew of the messenger.
Albert's advice: Other famous examples
We cannot solve our problems with the same thinking we used when we created them
The true sign of intelligence is not knowledge but imagination
We still do not know one thousandth of one per cent of what nature has revealed to us.