I have this (apocryphal) anecdote from Norman Lebrecht’s new book, “Genius & Anxiety,” an erudite and delightful study of the intellectual achievements and nerve-wracked lives of Jewish thinkers, artists, and entrepreneurs between 1847 and 1947. Sarah Bernhardt and Franz Kafka; Albert Einstein and Rosalind Franklin; Benjamin Disraeli and (sigh) Karl Marx — how is it that a people who never amounted even to one-third of 1 percent of the world’s population contributed so seminally to so many of its most pathbreaking ideas and innovations?

The common answer is that Jews are, or tend to be, smart. But the “Jews are smart” explanation obscures more than it illuminates. Aside from perennial nature-or-nurture questions, there is the more difficult question of why that intelligence was so often matched by such bracing originality and high-minded purpose. One can apply a prodigious intellect in the service of prosaic things — formulating a war plan, for instance, or constructing a ship. One can also apply brilliance in the service of a mistake or a crime, like managing a planned economy or robbing a bank.

But as the story of the Lithuanian rabbi suggests, Jewish genius operates differently. It is prone to question the premise and rethink the concept; to ask why (or why not?) as often as how; to see the absurd in the mundane and the sublime in the absurd. Where Jews’ advantage more often lies is in thinking different.

Where do these habits of mind come from?

There is a religious tradition that, unlike some others, asks the believer not only to observe and obey but also to discuss and disagree. There is the never-quite-comfortable status of Jews in places where they are the minority — intimately familiar with the customs of the country while maintaining a critical distance from them. There is a moral belief, “incarnate in the Jewish people” according to Einstein, that “the life of the individual only has value [insofar] as it aids in making the life of every living thing nobler and more beautiful.”

And there is the understanding, born of repeated exile, that everything that seems solid and valuable is ultimately perishable, while everything that is intangible — knowledge most of all — is potentially everlasting.